Your Auto Painting Questions
Answered
This page is
jam-packed full of car
painting tips and steps on how to paint a car
in answer to your auto painting related questions.
All answers are given by our resident auto painting
industry expert Dave Gage, Car
Cosmetics. There
are some extremely valuable car painting tips provided here,
with the list increasing weekly.
A good number
of topics have been covered for your convenience
such as how to setup a paint spray gun, applying clear
coat, auto paint mixing and heaps more important
steps on how to paint a car.
Each topic has been
categorized clearly to make it easy for you to navigate your
way through this page.
Our Topic
Areas
1.
Paint Spray Gun
Related
2.
Clear Coat
Related
3.
Auto Paint
Mixing 4. Welding &
Preparation for Paint
5.
Auto Paint
Chemistry - Acrylic Lacquer/Enamel.
6.
Surface
Imperfections -
Causes of Orange
Peel, etc.
7. Automotive
Paint - General
Questions
8. Painting Vehicle
Accessories -
Front Bar Cover
9. Paint Brand
Recommendations
10. Special Effect
Additives –
Pearl, Metallic
11. Dealing with
Rust
12. Supporting
Products - Paint
Primer, Sealer
13. Applying Aerosol
Paint
14. Working with
Fiberglass
15. Custom Paint
Finishing – Candy
Apple Red Application
16. Full Vehicle
Re-Spraying
17. Graphics - Application
18. Auto Scratch
Repair
19. Paint Job
Accessories -
Heat Lamps, Sanders
20. Repairing/Painting
Plastic Parts
21. Masking
Related
22. Paint Application
Related
23. Painting
Rims
24. Sanding
25. Compressor
Related
1. Paint Spray Gun Related
Question:
I'm new to working with water-based paints, could you tell me
what I need to use to clean my gun with after use?
Answer:
Quite simply, to clean your gun after using water-based paints
use clean tap-water.
Question:
I'd like to learn more about which paint spray gun to use. The
guns I have are dev620/dev670, my 620 I use to spray on base
coats and my 670 to spray on clear coats and
single-stage.
In your opinion, which is
the better gun to use SATAjet or DeVilbiss?
Answer: As
for which spray guns are the best, well that's not really a
question we can answer easily. Both makes are excellent and do
what they are designed to do.
However, there are many
professional painters who favor one over the other, not
really for any other reason than for the feel of it. I (Dave
Gage) have used both and I really favor DeVilbiss, only because
of the weight, balance and feel. Both makes of spray guns are
in the global top 5 and are renown worldwide for there
reliability and excellent construction. In addition, both guns
are proven in the motoring world.
So to re-cap, it's a matter
of personal choice when choosing a paint spray gun. We suggest
you try both makes and choose the one that feels right for you.
Don't make the mistake of choosing the paint spray gun that
looks the best or costs more/less; when painting cars the paint
spray gun you choose will become an extension of your arm, so
like a pair of shoes it needs to feel and fit just
right.
Question:
My vehicle surface is clean, smooth and ready to go. I have an
FX300 paint spray gun from Sharpe. It says to run it at about 29 psi at
the gun. I have a 3.5 hp compressor with a 60 gallon
capacity. The cfm (cubic feet per minute) is 15.8. I have a
moisture filter at the gun and one at the tank.
I also have a pressure gage
at the gun. I'm running about 50ft of 3/8 inch hose to the gun.
I need this due to the distance from the truck. I may have
in the past had too wide of a fan spray, about 9 inches. Also
in the past, due to not understanding what I was doing, I was
about 5 inches away from my material, trying to keep the
material going on wet and thinking each coat had to be glassy
smooth, which then created too much material going on too fast
and therefore paint runs.
I believe I've learned that
the first coat doesn't have to be glassy smooth, but clean.
Second coat goes on when the first coat is tacky but not sticky
and the third coat goes on?
Any imperfections can be
sanded and buffed out. I thought the 3rd coat was to be
PERFECT?
My spray temp has been
between 70 degrees Fahrenheit and 80 degrees Fahrenheit.
Humidity?
The other area I suspect is the reducer. The paint I'm using is
a 2:1:10%. It feels like I may need 15% because it just does
seem to lie down.
I did a test on an old hood
I have and it was better, but like I say it wouldn't lay down.
I still have little bumps, not orange
peel, but little
bumps.
At this point any
other tips you can email my way would be
appreciated.
Answer:
What we recommend is as follows:
Generally speaking if you
are using a conventional type of spray gun you ideally need a
constant pressure of around 70 psi, anything lower and you risk
applying the paint too thick/too heavy, hence the surface
imperfections: lumpy/bumpy appearance.
Our best advice would be to
upgrade your compressor. Although you're using a compressor
with a 60 gallon capacity tank with a cfm of 15.8, most
conventional spray guns need up to around 19 cfm. HP
(horsepower) isn't really an issue in your case.
You say that it tells you to
run it at about 29 psi, however this is dependent on the type
of material you are spraying, 29 psi does seem rather
low.
We currently use 2.5 bar
which equates to around 37.5 psi (1 bar = 15 psi.)
Question: I
would like to know more about the different kinds of automotive
paint spray guns, how to setup a paint spray gun and how to use
a paint spray gun correctly?
Answer: The
following car painting tips are very valuable as this is an
important part of auto painting to understand and get right.
Our best advice to learn how to use an automotive paint spray
gun would be to watch How to Paint
a Car - The
System (Part 1 & 2).
This shows auto painting
professionals demonstrating on-screen how to correctly use
paint spray guns, especially in relation to the surface being
painted. This is extremely important if you want to achieve a
uniform paint finish.
Paint companies recommend
specific paint spray gun setups for applying their products
with. This would indicate a specific fluid tip and air cap that
should be used with the particular paint product that would be
available from the dealer of the paint spray gun.
This is a great reason why
you should purchase your paint spray gun from a paint supply
store instead of from a tool store that sells a variety of
tools without servicing any of them.
These settings are available
from information sheets and application guidelines or from your
auto paint supply store worker.
For further information on
how to setup a paint spray gun, please refer to
'How to
Paint a Car - The
Written Guide'.
For risk of repeating
ourselves, we recommend you take a look at our
"Auto Painting
Tips" newsletter
archive and issues 02
& 03
on Paint Spray
Guns.
In there we talk about HVLP
spray guns (High Volume Low Pressure), different types of paint
spray guns, what you must consider when purchasing a paint
spray gun, how to thoroughly clean a paint spray gun and paint
spray gun manoeuvrability.
You will also find
information in those issues about why purchasing an expensive,
top quality HVLP paint spray gun will more than pay for itself
in just a few paint jobs; saving you money overall.
Question:
What car painting tips do you have regarding the use of
hardener & thinner when spraying auto paint primer through
a paint spray gun?
Answer: It
depends on which type of auto paint primer you use. If 2k auto
paint primer is used then hardener should be used, if it's air
dry auto paint primer then thinner should be used.
Question:
Do you have any data on what types of paint spray guns I should
use for base coat clear coat application and auto paint primer?
Any info on the correct PSI settings and spray fan
settings?
Answer:
Various countries use different types/makes of paint spray
guns, here in the UK we generally use either
(SATA or DeVilbiss GTI's).
As for the setup, well there
are many types dependent on what types of paint you are using.
Again here in the UK, most auto body shops only use water-based
paints and HS lacquers.
Try speaking to your local
auto paint supply store and asking them the same question for a
second opinion.
2. Clear Coat Related
Question:
My dark blue 1994 Honda has peeling clear coat on the bonnet
and roof. To respray, does all the clear coat have to be
removed? I propose to give it a good wet sand, followed by a
primer to aid adhesion and coverage of minor scratches and bare
bits, base coat and new clear coat.
Answer:
Yes, the way to do it is to flat (sand) the peeling clear coat
back (so no more peeling is evident), then apply a light coat
of primer (x2) should be enough. Then when fully dry apply 2 to
3 coats of base color. Then when dry, lacquer the full area
with 2 coats of clear coat.
Question:
The lacquer/clear coat finish I have is shinier than my first
attempt but still not perfect. Would using a rubbing compound
improve the situation or would I be wasting my time? If you
think I should try buffing it up what product would you
recommend?
Answer:
Indeed buffing the lacquer would improve the gloss
finish.
We recommend that you use a
fine grade wet and dry flatting (sand) paper first.
Lightly flat (sand) the
lacquered panel with 1500-grit wet and dry paper, then
use Farecla rubbing compound.
Apply a small amount to the
panel and use a machine polisher to gently polish the panel
with. Once happy with the finish, hand polish the panel and use
a quality wax polish i.e. Autoglym super resin polish, this will seal and
protect the finished panel.
Question: I
have a motorcycle and I decided to change the color. I didn’t
use any finishing coat or top coat. Will the color of my
motorcycle look shinier if I use a top coat or a finishing
coat? Do I have to use sandpaper before I apply the finishing
coat? What grade of sandpaper should I use?
Answer: The
panels of the motorcycle should be flatted down using
1,500-grit wet and dry sandpaper.
The color you then wish to
apply will of course now be done so over a newly flatted
(sanded) surface.
Approximately between 3-5
coats of color may be applied to the panels.
Then up to 3 coats of clear
coat/lacquer. This would indeed give the finish that showroom
shine.
Base coat isn't shiny but
matte in appearance, the glossy shine comes from the
lacquer.
Question:
Using the methods outlined in your video I successfully
prepared, primed and base coated the areas which required
attention. However I have not as yet mastered the application
of the finishing lacquer coats. The finish is OK but is more of
a matte finish than a clear gloss. What if anything
would you think I had failed to do?
Answer:
There is no set defined method of painting. Many painters
employ various methods of applying lacquer/clear
coats.
To achieve optimum results
when applying base coats and clear coats, it should be carried
out in a warm, environment, a temperature of at the very least
22 degrees C, with plenty of ventilation and sheltered from the
elements. Paint does not respond well to temperatures below 22
degrees C.
Also, when applying lacquer,
be careful not to apply too much, too soon. Apply one coat,
leave between 5-15 minutes before applying your second coat.
Once the second coat has been applied, if the finish is
shiny/glossy at that point, do not apply any more lacquer. It
is not a case of the more you apply, the shinier the finish
becomes, it doesn't work like that.
Question:
My car color is white, I need to re-paint it the same color.
Please let me know if I could use a clear coat to finish the
job so I can get a better gloss on my white car or can I mix
clear coat with the final coat of white paint? Is it true if I
use clear coat on my white color car it will change color after
some time?
Answer: If
you use a clear lacquer over the top of white 2 pack
gloss/solid, depending on the make and quality of the clear
coat/lacquer, it may well discolor (go yellow in
appearance).
This is largely due to the
pigment in the clear coat, although lacquer is almost clear, it
is in fact opaque, with a yellow tinge. You would clearly see
this by emptying a gallon of lacquer into a clear plastic
container and holding it up to the light, easily seeing the
color difference.
Always remember that you get
what you pay for with auto painting.
If you spent just $30 on a
gallon of lacquer don't complain if the color looks off after
so long a period, whereas if you spent $300+ for a gallon of
lacquer, the end result would have much more longevity if it
would ever degrade at all.
Think of white 2 pack gloss
as a colored lacquer (paint+lacquer), there would be no sense
in applying a further coat of clear lacquer to a coat of
colored lacquer which is essentially what white 2 pack gloss is
- white lacquer.
Our advice, would be to
paint the vehicle in a white base coat then use a clear coat
for that showroom shine. The purpose of using a base coat clear
coat application is that the base coat will compensate the risk
of de-coloration from the lacquer, it would do this by being
brighter from the onset.
Some issues with 2 pack
gloss paint are related to heavy metal content which is
considered unsafe for the environment.
Question:
Is there a way to safely remove peeling clear coat from undamaged paintwork
underneath?
Answer: The
answer to this question is no, not really. The clear coat binds
itself to the undercoat color. Peeling is usually a sign that poor quality
materials have been used to paint the car with.
3. Auto Paint Mixing
Question: I
don't understand the thinning out recommendations on paint
products, can you give me a simple form for etch, clear and
base coats for 500mls?
Answer:
Thinning for different types of paint products requires
different amounts. The general rule of thumb with
solvent based paint products is as
follows:
1. Etch Primer = 1:1 ratio (1 part paint to 1 part thinner)
2. Primer = 2:1:1 ratio (2 parts paint to 1 part hardener &
1 part thinner)
3. Base Coat = 1:1 ratio (1 part paint to 1 part thinner)
4. Clear coat = 2:1:10% ratio (2 parts paint to 1 part
hardener and then add 10% of thinner).
Please note: These are fairly generic ratios. As a customer,
you should ask the paint supplier for a technical data sheet
for all the types of paint being used, as they carry all of the
information required to use these materials i.e.
pressure/temp/air-cap/nozzle size, etc.
Question:
We are doing our first paint job on a small project. For the
primer (Tintable Polyurethane) we bought the tint.
They said 5-1 including the tint. Now what do they mean 5-1?
The paint gun is gravity feed nothing fancy so how do we mix
the correct amount?
Also the Paint (Low VOC Polyurethane Enamel) they said that it
is a 3-1 of Acetone and Catalyst, how will we mix
that?
Answer:
Firstly, the ratios to which you mix any paint are relative.
i.e if the ratio is 5:1, then this indicates 5 parts of paint
to 1 part of hardener/thinner/catalyst. So in broad terms the
ratio should always be the same.
For example:
 |
If you were to mix
5 liters of paint, then you would add 1 liter of
hardener/thinner/catalyst. |
 |
If you were to mix
2.5 liters of paint, then you would add 0.50 liters
of hardener/thinner/catalyst. |
The same rule applies for a
ratio of 3:1 - 3 parts paint to 1 part
hardener/thinner/catalyst. So to mix 3 liters of paint, you
would add 1 liter of hardener/thinner/catalyst.
As for the amount you would mix to do a particular job, well
that depends on the size of the individual panels. Rule of
thumb usually indicates that 1/5th (20%) of a liter per
panel.
This would allow for 2 to 3 quality coats per panel. The larger
the panel, then more will be required.
Question:
How do you mix the base coat and the clear coat? Also, I wanted
to put flake into it. What is the best way to do
that?
Answer:
Dependent on the manufacturer and make of paint, generally
speaking, base coat is mixed 2:1 (using a 2k base product of
solvent base.) Which means 2 parts paint : 1 part thinner
should be applied.
Lacquers:
using a MS (medium solid) system lacquer, again should be 2:1 -
2 parts lacquer/clear coat : 1 part hardener plus depending on
the environmental temperature anywhere between 5-10% of
thinners.
We covered metallic paint in
"Auto Painting Tips" issue 27.
Question: I
would like to know how to mix car paint so I can use it in my
spray gun, including how much thinner & hardener should I
use?
Answer: You
see, it really depends on what type of paint you are
using.
If it is a 2 pack type paint
then you would generally use 2 parts paint to 1 part hardener,
with a touch of thinner, usually 10%.
So the rule of thumb would
be a ratio of 100:50:10 of paint:hardener:thinner
respectively.
The best car painting tips
we can give you on this topic with paint mixing being a
systematic process, is that if you prepare the surface of your
vehicle properly, mix all products correctly and apply them
correctly, you will be left with an excellent paint
job.
The proper paint
mixing ratios are included with product information
sheets. Calibrated mixing cups and measuring sticks
are available at your auto paint and supply store.
If you are ever in any
doubt, simply ask for advice from a member of staff who you
bought your paint from, it is their job to guide you
accurately.
Color shade paint mixing on
the other hand is really a job you should leave to the
full-time professionals.
They will follow stock
vehicle color codes or codes attained from paint chip
catalogues. This service they provide forms part of the paint
system you purchase.
Question:
I've got hold of a 2 HP (horsepower) compressor and I've picked
up a Big Gazebo, (both were cheap as finance is a major
problem).
The thing I'd like to know
is:
a) How to Mix the Paint?
What ratio of paint to thinner?
b) Can I get away with
buying different makes of paint, thinner, auto paint primer and
clear coat from somewhere like eBay? What are the associated
risks?
c) How Much Paint Primer,
Color, Clear Coat will I need to paint my Alfa Romeo 156? How
would I find this out?
Answer: For
part a) please refer to our answers previously given on
auto paint
mixing.
There are many risks
associated with paint mixing the various types/makes of paints.
The best advice would be to buy all from the same manufacturer,
as part of the same paint system.
The better quality paint
products that you use the more desirable and durable the end
result will become.
As for the quantity, this
depends on the color and condition of the existing paint
finish.
A safe rule would be to
always buy more than you require, the supplier you purchase the
paint materials from will be able to guide you, it's their
job.
4.
Welding & Preparation for Paint
Question:
I'm currently buying a XB Falcon ute with a considerable amount
of rust. What I want to do is cut it out and replace it
with rust repair
panels. I can
use a mig or a tig but which one would be the preferred
welder?
Then after that, I would
like to know how to get to the final part of painting, that is
the step by step process for stripping and getting the car
ready for paint.
I'm going to be leaving the
ute in the same color, so do I have to rub back the whole ute
or can I wash it and then paint straight over the top of the
old paint?
Answer: Use
mig welding to weld in the rust
repair panels and as for the paint work, wash the car
using a strong detergent, DO NOT WASH AND WAX!
Primer and paint will not
stick to dirt, wax, or grease. This is why you will have to
take your time to remove all such debris from the surface of
the vehicle being repaired using wax and grease remover. This
will leave the surface as clean as possible.
You will need to be
meticulous in this area. It is important you do this after you
wash the vehicle, before you sand it, after you sand it and
between undercoats and top coats. Remember that each paint
system will come with its own recommended products.
Then flat the old paint work
using 800-grit wet and dry flatting paper before applying the
new paint.
Question: I
currently have a maroon red Honda Civic hatchback and wish to
spray it blue do you have any advice?
I was also wondering about
surface prep, the paint is already in good condition and I want
to remove it, how deep do I have to sand it down?
Answer: You
really don't have to remove the paint, no need to make
unnecessary work for yourself.
The original paint work
needs to be lightly sanded, using 800-grit wet and dry
sandpaper, this will provide a sufficient base for new layers
to bond to.
Any repair work should be
carried out, only prime the areas that require it, then apply
the new color.
5. Auto Paint Chemistry - Acrylic
Lacquer/Enamel.
Question:
Please explain to me the difference between Acrylic Lacquer and
Acrylic Enamel.
Answer: For
all intents and purposes, the use of lacquers and enamels in
automotive painting is obsolete.
Alkyd (natural-based) and
acrylic (plastic-based) enamels dry by evaporation of the
reducers first and then by oxidation of the resin or
binder.
The result here is that the
paint finish may appear to dry quickly through evaporation of
its solvent base however, the material continues to harden as
resins combine with oxygen in the air.
This is why infra-red lamps
were used; the heat from them would speed up this
process.
During this curing process,
a dry synthetic film would solidify over the top of the finish
to offer a tough, shiny color coat.
Wet sanding this coat to
remove bits of dirt or debris would destroy that film and
require touch-up painting to repair the surface
blemishes.
When compared to the
durability of Urethane products, alkyd and acrylic enamels fall
way short.
Although they can cover in
just one or two coats they cannot hold up to the same kind of
harsh environments.
In addition, the application
of any lacquer based product over enamel would result in
surface wrinkling
. This is because the
materials in enamel cannot hold up to the strong
chemicals in lacquer.
A special sealer has to be
applied first to prevent lacquer solvents from penetrating and
ruining enamel bases.
Acrylic
Lacquer has been a favorite paint among auto
enthusiasts for years.
It is easy to mix, can be
applied at relatively low pressures, dries quickly and can
generally be repaired and re-coated within 10 to 20 minutes
after the last coat has been sprayed making it popular with
custom car painters.
Lacquer requires a number of
coats to achieve color and coverage expectations. Then coats of
clear lacquer are sprayed over color bases for protection and
for required buffing.
To buff lacquer color coats
you would affect the color tint. This is why clear coats are
applied so that buffing shines them to a showroom finish
without disturbing the underlying color base.
Due to the amount of
Volatile Organic Compounds (VOCs) emitted by lacquer solvents,
regulatory agencies minimized the use of lacquer paint or
required that it only be sprayed in down-draft paint spray
booths equipped with special filters and air-purifying
systems.
This is a factor to consider
if you're contemplating a complete paint job for your
car.
If you are using Acrylic
Enamel or Lacquer then we recommend you consult an auto
paint supply store member of staff for advice and
recommendations that apply to your specific need.
Question: I
have a 1974 Challenger that currently is painted enamel red,
underneath is the original b5 blue metallic enamel.
Is there anyway to paint
this with lacquer without taking it to bare metal to do
so?
Answer: If
the enamel is a synthetic based product then you can't apply 2k
clear coat over the top, it will cause crazing.
6. Surface Imperfections
Questions:
For two years I’ve worked with SPIES HECKER PERMAHID water
based paint and I have one problem: On the light colors (EXL
from Peugeot) or silver color, the base coat always dries
spotted (cloudy). I try more or less base coat reducer, low or
high pressure, two full coats and dry coats, dry between coat
and still no joy! Maybe you could tell me where the problem
lies because I ask the technicians from Spies Hecker and they
say this is not possible. With Dupont or Autocolor I don’t have
this problem.
Answer:
Spotting/clouding in light colours i.e. silvers/blues etc. is
largely due to low temperatures during application and damp
conditions.
Firstly, when applying the
base coat colour, apply one light coat first, followed by 2
full coats as soon as the first coat is dry (do not allow the
second and third coat to dry in between).
Then when dry, tack cloth
clean the surface before applying the drop coat, usually 1 to 2
drop coats. Ensure the base coat is fully cured before applying
clear coat.
TIP: Water based paints
respond better to infra-red curing rather than low bake or by
using compressed air being blown onto the surface.
Question: I
recently painted some areas on my car that had scratches on
them. I noticed that one of the areas I painted I could still
see sandpaper scratches under the paint. How can I correct
this?
Answer:
Scratches under the base coat are a result of poor preparation.
To rectify this, the area should be flatted down (sanded) with
800-grit wet and dry sandpaper, then apply 2 coats of 2k
primer. When dry, wet flat with 800-grit wet and dry paper once
again, then apply 2 to 3 coats of base coat, then
lacquer.
Question: I
would like to know what causes edge mapping (when primer edge
can be seen under dry paint) and how this can be
stopped?
Answer:
Mapping is caused by a couple of things:
1 - Area not flatted properly prior to primer being
applied.
2 - Primer not flatted properly prior to painting.
Solution: Prepare the surface area properly,
i.e before applying primer ensure all repairs are flatted with
800-grit wet and dry sandpaper, then dry and pre-clean with
panel wipe. Apply 2-3 coats of 2k primer (not aerosol primer)
when dry, flat using 800-grit wet and dry along with a flat
rubbing block to ensure that the area is completely
flat.
Question: I
have a 1988 Honda Shadow VLX 600 with metal fenders and gas
tank, other pieces are plastic.
I'm trying to use spray paint to paint it. I hear it's possible
for a novice to make spray paint look like a professional paint
job given the right instruction?
Well here's what is happening...I sanded the plastic down using
320-grit paper. Then I used filler primer, I put about 7 coats
on.
Then I wet sanded it with 1000-grit paper, had it baby smooth
and looking beautiful. Then I used regular primer over that,
wet sanded that down with 1000- and 1500-grit.
Then I used truck and suv black spray paint gloss I think. I
put 7 coats of that on, looked really good but had
orange peel. I was told to spray clear over that,
then wet sand it.
When I sprayed the clear, I don't know why, it must not have
been dry because it wrinkled up when wet sanding. Why do you
think this happened?
That is problem 1, problem 2: I followed the exact same steps,
except I let the paint dry for 3 days then wet sanded it, then
1 hour later shot it with clear truck and suv spray paint.
It instantly crinkled up and cracked REALLY bad! It looks like
it's been burned! I cannot figure out what is going on so maybe
you can tell me how to do this properly?
I've almost got the pieces sanded back down, now I just want to
do it right this time as it's getting very
expensive.
Answer: It
sounds like the paint products you're using are incompatible
with each other, hence the unwanted reactions you're
experiencing. Make sure that the paint products being used are
fully compatible and are part of the same paint system, ALWAYS!
We also suggest using 2k products only.
We suggest that once the primer is fully dried (best way would
be to use a hired heat lamp for 40 minutes) wet flat with
800-grit wet and dry paper. Then apply only 3 to 4 coats of
black followed by 2 coats of clear coat.
Once fully dried again (using a hired heat lamp for 40 minutes)
gently wet sand to remove any orange
peel and dirt
inclusions using 1500-grit wet and dry paper.
Then gently machine polish to a high gloss finish.
Question:
The hardener I was working with hardened at the bottom of my
spray container, the effect was an orange
peel texture after
applying the mixture. My remedy was to decrease the paint
flow volume and increase air pressure. Was I right in doing
this to eliminate the orange
peel effect?
As far as the hardener
problem, I mixed the two for a longer period but then would get
tiny clumps sprayed out of my spray gun nozzle. Poor cleaning
of the spray gun perhaps? Please advise.
Answer:
When paint mixing any 2pack component, it is essential the two
components are mixed thoroughly.
Depending on the air
temperature, it may well have to be applied fairly quickly
(usually within the hour), an ideal temperature would be around
22.5 degrees C.
Then the spray gun should be
emptied and cleaned out straight away to avoid the epoxy drying
in the spray gun.
Orange Peel is usually down to a combination of
faults. Please refer to our Auto
Paint Repair section
on Orange Peel for a detailed breakdown of the surface
condition, causes, preventions and solutions.
Question:
Thanks for your expertise. I am learning a lot and I feel my
project ('97 Ford F150 GT) will be a great success with your
support.
However, I have painted a
few work trucks and though my preparation work on the bodies
has been thorough, my application of the paint has left me with
a lot of wet sanding.
There has been a
pin hole like orange
peel effect and even
after wet sanding for hours on end I still get little
pin holes. Most people don't see it but I can and
it is unacceptable to me. I want my truck to be a show stopper!
Any advice?
Answer:
Please refer to our Auto
Paint Repair section
on Orange Peel for a detailed breakdown of the surface
condition, causes, preventions and solutions.
As for pinholes, this is usually caused by too much clear
coat being applied, again 2-3 coats is all that should be
required.
Specific lacquer and
urethane paint finishes can be wet sanded and polished to
remove nibs, flatten orange
peel and smooth out
blemishes.
This work is normally
carried out on clear coats instead of on actual color coats and
may require additional light applications of clear
afterwards.
This is why professionals
will rarely remove the masking from a vehicle until they are
pleased with the entire paint job and are sure that they have
taken care of all imperfections.
7. Automotive Paint
Question: I
wish to paint my 1987 Corvette flat black, it’s currently in
gloss black. No body work is needed and all trim will get the
flat black treatment.
Can I simply scuff the surface with 800-grit and shoot it with
the flat black? Will the new paint job need wet sanding after
completion?
Answer:
Flat the car with 800-grit wet and dry, mask the car then apply
2 to 3 coats of 2k matte or satin finish black. Providing there
are no imperfections or problems then no further work will be
required.
Make sure when ordering the paint that you order 2k matte/satin
finish. The reason for this is that the auto paint supply shop
will mix in the matting agent for you.
Question: I
have a query about the water-based paints that are on the
market. Are they more expensive than the other paints or are
they cheaper? Usually I was buying a liter of paint for under
£20, could you tell me roughly how much these new paints are
going to set me back?
Answer:
Indeed water-based paints are much more expensive and depending
on the product make, you could be spending anywhere between £45
to £90 per liter in the UK market.
Question: I
have a question about the new water-based paints that are now
available because cellulose has been taken off the
shelves.
Can you tell me more about
this new paint and is it better or worse than cellulose because
I used cellulose a lot and I don't really know much about this
new paint. I've done a lot of research on water-based paints
and I find people have mixed feelings. What do you guys think
of this new system?
Answer:
Indeed there are a lot of mixed feelings out there with regards
to water-based paints. Modern paint technology is far superior
than many people think.
Mixed feelings are a result
of new technology vs. old mind-set, i.e. many professional
vehicle painters are not welcoming of change, and because they
don't fully understand water-based paints, they don't like
using them. It's hard to teach an old dog new tricks!
The truth is, water-based paints are extremely good and have
secured their place in the motor repair industry. The downside
is that many auto body shops now have to invest in brand new
equipment, spay guns, new ovens, etc. because the old drying
technology isn't sufficient enough to cope with water-based
products.
Our personal feelings are that water-based paints are better
than 2k paints purely because they don't require as much to
cover and are far less harmful to the environment.
Question: I
have primed my car with 2k-beige primer and at the moment it is
sat there rubbed down to a 1500-grit sandpaper
finish.
I rubbed it down in stages
from 600-, 800- onto 1500-grit. I have checked it over and over
for any imperfections and all is well.
I bought midnight blue paint
and was told to just mix it 50:50 with 2k thinner without any
hardener.
The car has been prepared
including back of doors, door wells and the back of the boot
and bonnet.
I was told that 5 liters of
ready to apply paint would be enough, is this true or would you
advise me to buy a bit more to be sure?
Also, I am unsure of the
room temperature the 2k paint has to be applied to the car in,
is it about 60 degrees Fahrenheit?
I just need to know a bit
more about the base coat/room temperatures/how long you leave
the paint to dry between coats?
Please could you give some
more advice on the stages that come after the car has been
primed?
Answer:
50:50 is the right paint mixing ratio for 2k base coat. As for
the quantity of paint needed, this will usually always depend
on the opacity of the color being applied.
For example, when covering a
light colored primer, you will need to use more of a dark color
(midnight blue) than a lighter color, due to the high contrast
between the two.
Painting yellow or a similar
light color over a light colored primer will generally require
less paint.
The same rule applies when
working with darker colors; if you use a dark colored primer
such as dark gray, then less dark colored base coat will be
required.
Discuss this with your auto
paint supplier, they will advise you according to your budget,
on the best paint set-up for your project.
As for temperatures, the
panel temperature should be around 25 degrees C with paint
applied in a dry atmosphere.
The ambient temperature
should also be around 25 degrees C, drying times between coats
should be around 5 to 10 minutes.
Don't forget that 2k base
coat is only a color and will require 2k clear coat lacquer
over the top. A correct base coat clear coat application will
always give you a top coat with a glossy showroom
finish.
Usually 2-3 coats of lacquer
is all that will be required.
8. Painting Vehicle Accessories - Front Bar Cover
Question:
I'm painting a VN and have purchased a new front bar cover. I
have wet sanded it using 400-grit sandpaper and then cleaned it
using wax and grease remover.
The problem is I can't get
the paint to sick to it! I'm also having trouble with fry ups
in the paint, is that because the temperature is too cold or
because the surface is not clean enough before
painting?
Answer:
Firstly, establish what the the cover is made from. If it is a
plastic type material, it will require an adhesion
promoter.
This is a special type of
plastic primer, which should be used once the cover has been
flatted down and cleaned using wax & grease
remover.
Usually this product can be
purchased in aerosol form with 2 coats needed at room
temperature, 25 degrees C.
Then a 2k primer should be
applied over the cover, 2 coats will be enough.
If the cover is to air dry,
leave it for at least 24 hrs. at room temp.
Then wet flat using 800-grit
wet and dry flatting paper.
Apply the color in light
even coats leaving 5 to 10 minutes between coats.
Don't try to apply too much
color with the first application, this is usually the
cause of cracking
or crazing.
Usually 2 to 3 coats of
color will be enough, dry for around 30 minutes at 25 degrees
C, then 2 to 3 coats of clear lacquer should be
applied.
Again light even coats
leaving 10 to 15 minutes in between. Leave to dry again for
around 24 hrs at room temp.
9. Paint Brand Recommendations
Question:
Here in the United States there is PPG paint and Dupont paint
including several others. What brand do you
recommend?
Answer: To
be fair and honest, both brands are very good and there is very
little difference between them both.
In terms of overall paint
quality, there isn't much in the way of poor quality in use
nowadays.
10. Special Effect Additives – Pearl,
Metallic.
Question: I
painted my car with metallic paint 2 months ago and now I can
see some small scratches which I patched beforehand. In
addition, the shine of my clear coat is a little down. Please
help.
Answer: The
scratches have appeared largely due to poor preparation before
the metallic paint was applied.
Best advice, re-flat the
area using 1,500-2,000 grit sandpaper (wet and dry), using 2-3
coats re-apply your metallic color, being extra careful not to
apply too much.
Once the base coat has dried
(cured) apply up to 3-4 coats of clear coat/lacquer.
If it is an air dry product
that is being used, leave for up to 24-48 hours to cure
properly before you commence polishing. This would then restore
the gloss finish.
Question: I
find your "Auto Painting Tips"
newsletters very
interesting and helpful.
I'm doing up my Fiat Punto
as it's in desperate need of a re-spray. This will be my first
time spray painting.
I was going to spray my car
so that it changes color when you walk around it but thought it
would be too hard for a first timer so I've decided to spray it
black and put red and blue speckle bits into it.
Do I put these into the
paint or lacquer?
Also could you give me any
advice on the best way to go about it and what amounts of paint
I would need, etc.?
Answer: You
will need to introduce a pearl stage into your base coat clear
coat application.
Firstly, purchase around 3
liters of black 2k base coat. Then 0.5 liter of red pearl
and 0.5 liter of blue pearl.
After applying all the black
base coat, apply 2 very light coats of both pearls, then 2-3
coats of clear coat.
11. Dealing with Rust
Question: I
understand that rust
removal can be
performed with a chemical stripper. This is new to me and
I was wondering if you could give me the name of this product
and whereabouts I might be able to purchase it?
Answer: You
can of course use a chemical stripper to cure rust however,
this is not the method that we favor the most.
The easiest and most
professional method, that indeed an auto body shop would use
and indeed any home auto painter, would be rust
removal by sanding.
However, if you want to use a chemical stripper, there are
various products on the market and indeed worldwide. The most
popular product is Jenolite. Jenolite can be bought from most auto paint
supply stores.
How does Jenolite work?
First, thoroughly clean the
infected area, brush the solution on, then leave it to work on
the rust (always following product guidelines.) You would then
wipe the area down, removing the rust and then primer straight
over the repaired area.
Always bare in mind that
rust is almost cancerous; it spreads once it has infected body
work. Whilst most chemical strippers will remove it, this
method is more of a retardant (makes the progress or growth of
rust slower) than a total cure.
The most secure way to get
rid of rust is to quite simply cut out any infected areas and
replace them with rust
repair panels.
However, this is not always
possible depending on where the rust is located on the
bodywork. If you cut the infected area out, there is absolutely
no way it can come back unless a new case of rust develops
elsewhere on the bodywork.
Question: I
want to fix some rust problems on my car, it has deep rust on
the wheel-arch and kick plate area.
I'm first going to remove
the bulk of the rust using 80's grit paper, do I then need to
apply some kind of etch primer, if so can I buy this in a
can?
Then, I apply the primer,
let it flash off properly, then rub with 320-grit then 500-grit
sandpaper?
I masked up the area to
protect from over-spray etc. from the top-coat and the etch and
primer coats.
How then do I apply the
top-coat to achieve good blending in?
Answer:
Yes, you will need to apply etching primer to the panel,
however this will only be needed if you sanded down to bare
metal.
If paint still remains on
the surface then no etching primer will be needed. Yes, etching
primer is available in an aerosol spray can.
Gently apply the color coat
in light and even coats, you only need to apply as much color
as it takes to cover the repair/primer area.
Then 2 coats of clear
allowing 10 to 15 minutes in between coats.
All else is
correct.
12. Supporting Products - Primer,
Sealer
Question:
What is the difference between primer and sealer?
Answer:
Primers are materials that are applied over
bare metal once the metal has been properly
prepared.
Their category comes under
the different products that are separately designed to provide
a variety of surface preparation functions.
Together, they can be
classed as undercoats: those materials applied to auto body
surfaces in preparation for paint applications.
These would also
include:
 |
Epoxy
Primer |
 |
Primer
(Primer-Surfacer) |
 |
Sealers |
Sealers
A simplistic definition
of sealer is that it forms a sort of barrier between the
undercoat and top coat (paint).
They really can be the
difference between an adequate paint job and an excellent
one.
In providing a little more
detail, the purpose of sealers is:
 |
To protect
undercoats from the materials and solvents in
subsequently applied paint top coats. |
 |
Add maximum
adhesion capabilities for those top
coats. |
 |
Ensure a uniform
color match. |
Question:
What would cause primer to "curl" in certain
places on the surface?
I tried to prime my truck
but the primer ended up not sticking at all and curled
terribly. I could peel it off like a weird tape, what
happened?
Answer: The
layer of primer is separating from the surface of the vehicle
because of a lack of physical bonding.
Checklist:
 |
Check if this
defect is on the whole unit or in specific
areas. |
 |
Check other units
to determine if a pattern exists. |
 |
Check for
contamination such as oil, sanding residue,
over-spray, water, solvent cleaner residue, etc.,
on substrate prior to primer
application. |
 |
Check for
non-sanding or etching primer. |
 |
Check that the
correct amount of hardener was used. |
 |
Check for poor
surface preparation prior to primer
application. |
 |
Check solvent
selection (too fast). |
 |
Check for
incompatible products. |
13. Applying Aerosol Paint
Question: I
would like some advice on how to go about spraying with
aerosols - things like wing mirrors & spoiler
fins.
Also, the main problem with
the paint work on my car are the scratches (through to primer)
on most panels. A re-spray is out of the question. Any advice
would be appreciated.
Answer:
Using aerosols to paint wing mirrors etc. is quite an easy
task. The same rules apply whether you are using a spray gun or
canned paint.
First, make sure the repair
area is clean from any dirt, dust and debris.
Then, the surface to be
painted MUST be flatted using 800-grit wet and dry paper also
any damage such as chips, scratches etc. should be
repaired.
The surface should then be
cleaned thoroughly and then primed before applying the
color.
As for scratches to the
bodywork, unfortunately if these are deep enough, then a
re-paint will be in order.
14. Working with Fiberglass
Question: I
have put a pair of side skirts on my car but I have problem
with them. After I had fitted them, I put a skim of filler over
the top of them to hide the join. I sanded the filler down and
primed and painted them but after a few weeks they had cracked
along the join. Could you tell me why this is? What can I do to
stop this happening again?
Answer: We
assume the kit is made from glass fiber? If this is so then the
kit needs to be flatted (sanded) down with 80-grit paper then
glass fiber should be applied over the joint (NOT BODY FILLER).
Then flat (sand) down the glass fiber with 80-grit paper before
applying the final coat of body filler. The reason it cracks
with the use of filler is because the filler isn't
flexible.
Question:
I’m painting a ‘07 Corvette fiberglass deck lid but having
trouble getting the paint to stick correctly. What am I doing
wrong, what should I do different?
Answer:
Fiberglass is a fairly easy product to work with and paint
over. Firstly, ensure that the gel coat that features on the
fiberglass surface is flatted (scuffed) correctly using
800-1000's grit wet and dry sandpaper. Making sure that you
scuff absolutely all areas both hidden and obvious.
Once you're finished
flatting down the whole surface area, make sure that any
imperfections on the lid are filled in using a 2k self-leveling
polyester finishing putty.
Once that is done, apply up
to 3 coats of 2-pack high build primer. Once this is done,
leave it to stand for 24 hours in an environment where
temperatures are not going to go below 20 degrees C.
Then flat (sand) down once
again using 800-grit wet and dry sandpaper all over for a good
key, i.e. so that the subsequent top coats are provided with
plenty to adhere to without any further fear of these coats not
sticking.
Referring back to the 2k
self-leveling polyester finishing putty, in the US, you will
find this product referred to as Bondo or Rage.
Question:
I'm currently working on fixing a fiberglass body kit onto my
car. On a basic level would you be able to give me some tips on
preparing it?
Also, what are the ratios
for primer, paint and lacquer when it comes to adding the
hardener and thinner?
Answer:
Fiberglass is easy material to work with. Firstly, make sure
that the kit fits properly by running a trial fitting, any
trimming should be done at this stage.
Then any splits, cracks or
pin holes should be filled. Then the kit needs to be flatted
down ready to be primed.
2k primer should then be
applied using 4 good coats, then flat down with 800-grit wet
and dry paper before applying the color.
As for the ratios this
depends on make and type of paint. Your best bet would be to
ask your paint supplier for a technical data sheet, this will
give you the correct paint mixing ratios to use.
15. Custom Paint Finishing – Adding
Stripes
Question:
I’m unsure of the steps involved to paint candy apple red
paint.
I was planning to lay down several coats of black, after that
do I wet sand it before laying down several coats of candy
apple? Will I then have to wet sand the candy apple?
Would I use a rubbing compound on the candy coat or only on the
clear coat?
Answer:
After laying down the black paint, when fully cured (if the
finish is free of any dirt/dust/debris) gently scotch the
surface with ultra fine grade scotch pads (like using ultra
fine sandpaper).
Then fully clean the surface
with pre-clean panel wipe (solvent based cleaner).
Then apply 3 to 4 coats of
candy coats (no need to sand the color). When dry, apply 2 to 3
coats of clear coat.
Question: I
have a 2006 Ford Mustang GT and I would like to paint racing
stripes on it. However, I'm unsure of the surface preparation
that is required.
What is involved and do I
need to plan on clear coating the entire hood, top and trunk
area?
Answer: It
really depends on the types of stripes being used. Ideally
painting them on is the best way to do them. If you can lay out
a pattern on your car with tape, you're halfway
there.
In this instance, it's not
only fast and inexpensive compared to other types of custom
painting, it's also easier to do yourself.
You may wish to look at
custom painted car magazines or visit custom painted car shows
to gain a good source of ideas.
Once you have a few designs
in mind, try drawing on a sketch of the car. You'll be able to
work out a lot of details that way and you may come up with a
better way to enhance the effect.
It is highly recommended
that you use a base coat/clear coat paint system for your
stripes. The original paint work needs to be lightly sanded
where necessary, using 800-grit wet and dry sandpaper, this
will provide a sufficient base for new layers to bond
to.
Finish by clear coating the
entire panel will ensure a nice flat finish with no edges
around the stripes.
A base coat/clear coat paint
system would be ideal if you intend to choose adding stripes
consisting of more than one color. That way you can apply two
coats of clear over the first color.
If you get any overspray
from the second color on the first, you can sand it out of the
clear without damaging the underlying color coat.
After applying the second
color (and third, if applicable), apply two or three additional
coats of clear over the area.
Flash and drying times are
also critical to a successful multi-color paint job. Applying
masking tape or masking paper to freshly painted surfaces that
have not yet dried adequately will cause you much more
work.
Product information sheets
will provide a specified time to allow the paint to dry before
taping.
Likewise, clear coats must
be added within a specified time or the base coat will need to
be scuffed again using 800-grit wet and dry paper and
additional base coats added.
16. Full Vehicle Re-Spraying
Question: I
would like to take this opportunity to know your personal
preference on how to go about re-spraying a whole
car.
To be more
specific:
 |
Do you paint the
hood, trunk lid, bumpers and doors in
situ? |
 |
How do you go on
about painting around the door shuts? |
 |
Do you take the
doors off first and paint the shuts (also finish it
off with clear coat) and then put the doors back on
and paint the outside of the car? But then wouldn’t
the overspray get in the door shuts through the
door gaps? |
 |
Or is there a
special way of masking the painted door
shuts? |
Answer: The
professional method of repainting a whole car is to remove the
doors, hood, and trunk lid from the vehicle. Once you
reach the paint application stage, the color would be applied
to all areas.
The doors are then re-hung
back onto the vehicle and so is the hood and the
trunk lid. Once everything is back on the vehicle, you
would then re-paint them again in-situ. Effectively, you are
painting the parts twice. This makes absolutely sure that all
areas are covered, but more importantly you don't need to mask
anywhere afterwards.
So to confirm: paint the
whole of the door (front and back), same with the hood and
trunk lid, hang them back on, open all these parts,
re-paint them, apply lacquer. Then shut them, paint the outside
of the car, apply lacquer.
17.
Graphics - Application
Question: I
am painting my truck. The base color is speedway blue and I
would like to put sun yellow graphics down the side. How do I
go about putting graphics on without messing up the base
color?
Answer:
This can be quite a difficult process to get it right. Unless
you are a skilled graphic designer, painting graphics will be
tough to achieve.
The easiest, cheapest and
most effective way is to have somebody cut them out of vinyl
and apply them to your vehicle, i.e. stick them on.
If you are feeling artistic
enough, you could always try using stencils to achieve what you
want, but unless you are able to get the edges of the graphics
absolutely crystal sharp, it could turn out to be a bad
idea.
Stencils are often used when
painting flames onto a car. However, the actual application
stage is carried out using an airbrush. The purpose of this is
so that the paint application is very thin and you don't end up
with a thick layer of paint all around the edges.
You could try visiting your
nearest reputable graphic designer and ask them to design and
make you whatever you require.
18. Auto Scratch Repair
Question:
What grade of sandpaper grit can I use on a deep
scratch?
Answer: Use
240-grit sandpaper first, going down to 320-grit in order to
fine off the surface before applying primer.
Question:
My wife and I just bought a Honda Odyssey and it has a scratch
in the door.
We do not want to paint the
entire door for one scratch. After getting the touch-up paint
from the local dealership what is the best prep and paint
method on getting the scratch to blend in to the original paint
job? Would you use a little airbrush gun to do the job and if
so what are some good ones to use?
Answer:
Touch up paint bought from a local dealership isn't the perfect
solution to get rid of a scratch, this is dependent of course
on the severity of the scratch.
The method that we would
recommend would be to flat down the scratch, i.e. sand the
scratch out of the panel, apply up to 3 coats of color over the
freshly primed area and then finish by adding a new coat of
clear.
By carrying out a local
repair on the scratch using touch up paint, you will find it
extremely difficult to blend in the repair properly with the
surrounding paint finish. Afterwards, it would be highly
visible where the scratch had been.
Always bare in mind that
touch up painting is only to be used for touching up minor
chips, scratches and nicks and is not meant to be used on
noticeable surface damage i.e. obvious scratches seen at a
distance for example.
19. Paint Job Accessories
Question:
Could you recommend any ideal heat lamps or sanders etc. and
where to buy them?
Answer:
Generally, 2-pack paint products should use medium wave or
short wave infra-red portable stand-up heating lamps, that can
be simply plugged into a mains electricity supply.
Most who work in the
automotive repair industry use medium wave infra-red. Any
decent quality automotive equipment supply store or auto paint
supply store would stock such items.
For sanders, again all you
would have to do is inquire down at your local auto paint
supply store or automotive distribution center.
Chicago
Pneumatic would
be an ideal choice of manufacturer to use for any home auto
painter, they offer dual action air sanders for example for
approximately $45+.
20. Repairing/Painting Plastic
Parts
Question:
I’m trying to paint plastic parts in my truck such as the
dashboard. After I painted it, some areas started to crack or
as some call it ‘spider web’ out. How do I prevent
this?
Answer:
First the dashboard needs to be cleaned thoroughly. Use a water
based solution containing a mild detergent (i.e. dish washing
liquid or similar). Next, clean again using a solvent based
cleaner (i.e. pre-clean panel wipe).
Next, using a fine scotch
pad or high grade sandpaper, lightly rub down the whole
dashboard (only gently to avoid deep scratches).
Then apply 2 coats of single
pack adhesion promoter (plastic primer clear).
When dry, after 10 mins at
20 degrees C, apply 2 to 3 coats of vinyl coat paint (this can
be bought from most paint supply shops).
Allow 5 to 10 minutes
between coats and allow to cure for 24 hours before
handling.
Question: I
damaged the Flares around the right front fender on my 2006
Toyota Tundra. I bought new flares from Toyota, they came
unpainted. How do I prep them for painting?
Answer:
First, clean the flares with a solvent based cleaner (i.e.
pre-clean panel wipe). Then flat with 800-grit wet and dry
before applying 2 coats of primer. When dry, flat the primer
with 800-grit then apply 2 to 3 coats of color.
Question: I
have ordered replacement bumpers/plastic rear corner covers
(e.g. Chevy S-10 Blazer, right/left corners) in the past and
when they’re shipped they arrive damaged sometimes with a deep
scratches that needs fixing. What is the best way to fix this
damage?
Answer: For
the time being, we can tell you that repairing plastic is no
different from repairing metal. The only thing that you do need
to be careful of with plastic in particular is that you use
flexible fillers.
When you visit your local
auto paint supply store to buy your products, explain to them
what you wish to achieve and what type of material you are
working with i.e. not repairing rigid metal panels but flexible
bumpers, etc. and they will give you the recommended product in
which to use.
21. Masking Related
Question: I
back-taped around the areas I painted but some of the spray
primer (not much) got under the tape, how do I prevent
this?
Answer:
Apply 2 lines of masking tape to prevent this.
22. Paint Application Related
Question: I
didn't blend my paint well and two of the areas I painted are
lighter than the color of my car, should I repaint these
spots?
Answer:
Increase the paint flow slightly to ensure the paint is going
on wet and not dry.
Question:
When I try blending in silver paint i.e. onto a bumper wing or
bonnet, I can't figure out how to stop that dull grey line
showing around the area just sprayed? I just end-up re-spraying
the whole wing/bonnet!
Please, please could you give me a few tips or simple ways to
avoid this?
Answer:
When painting silver it's important to remember that due to the
high metallic content of the paint, the silver won't lie down
on the panel that's being painted.
So, here's what you need to do:
Firstly, only spray the area that needs to have the colour i.e.
primer/repaired area.
When fully covered i.e. you can't see any primer bleeding
through the colour, let the silver dry for around 15 to 20
minutes at 22 degrees C.
Then lightly apply a further coat of silver, blending away from
the repair (remember that you are only blending away so don't
apply heavy coats.) Usually 2 light blending coats is more than
enough.
When fully dry (again 15 to 20 minutes at 22 degrees C) lightly
tack cloth the whole panel before applying 2 coats of 2k clear
coat.
To re-cap: Silver is difficult to blend away and to be fair,
even professional auto body shops often struggle to achieve a
perfect result. Often is the case to paint for example a door,
they often have to blend away down a full side. You're not
alone in your troubles with this one Emmett, however if you
follow this advice, you should start to see an improvement with
your results.
Question:
After sanding my primer with 1500-grit paper it was smooth, I
then applied 3 coats of paint which once dried had a rough
feel.
I applied my lacquer over
this and was left with a rough not smooth appearance. Should I
have sanded my paint or used a rubbing compound or should this
be done to the lacquer only?
Answer:
Once the vehicle was flatted (sanded) with 1,500-grit paper and
the base coat color was applied, if it dries with a rough feel,
that is a fair indication that the paint (base color) mixture
was either too thick or the paint was too cold, i.e.. the
environment in which you were painting in was below 22 degrees
C.
If the paint is too cold and
applied onto cold surface panels, due to cold environment
temperatures, it comes out lumpy (to emphasize the point.) It
doesn't flow properly.
So make sure that
you:
a) Are painting in an
environment where the ambient temperature is at least 22
degrees C.
b) That you have indeed mixed the paint mixture correctly
according to product mixing instructions.
You shouldn't have to flat
(sand) down base coat (color coat) in-between
applications.
We suggest that it was an
environmental issue you were having; it was perhaps too cold on
the day you were painting and the paint wasn't mixed correctly.
It won't be a product related issue.
23.
Painting Rims
Question 1:
Clear coat is coming off of the aluminum rims? What
can I do about this?
Answer: Lacquer doesn't adhere to bare metal
very well. The manufacturer would use a clear powder coating
and not 2k lacquer. Strip all the old clear coat off of the
rims (using Starchem
Paint Stripper or
Nitromors paint stripper). Then flat the rims using 800-grit
wet and dry flatting/sand paper (using luke warm water with
a touch of mild detergent – NOT WASH AND WAX detergent),
then polish the rims using metal polish (Autosol).
Question 2: Is it possible to get the rims
coated with powder again? Or is the metal polish going to
protect the rims just as well? The powder lasted about 12 years
- I'm not sure how long metal polish will last? Maybe I'd have
to polish the rims once a year or so?
Answer: I would polish them a couple of
times a year, they look much better than powder
coating.
24.
Sanding
Question 1:
Can I wet sand the base paint before I put clear on it for a
smoother finish?
Answer:
There should be no need to wet flat base coat before applying
the clear coat. If there is an issue with the base coat, wet
flat with 1200-grit wet and dry flatting paper, then re-apply a
further 2 coats of base. Try to ensure a smooth and even
application before applying the clear coat.
Question 2:
How long after I spray clear can I wet sand it?
Answer:
Clear coat can be wet flatted around 24 to 48 hours after the
application.
25. Compressor Related
Question:
If I use acrylic paint, will a 1hp compressor give a quality
spray?
Answer: As
for a 1hp compressor giving good paint results, I would say
not. The volume of air required is around 13/16 cfm (cubic feet
per min) most guns require at least this volume of air to give
good results.
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