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With Chris Curwen & Expert Auto Painter - Dave Gage (Car Cosmetics)

October 23rd, 2007 - Issue 26

In this issue:

• We cover modern day Urethane Paint.

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To follow on from last weeks issue on Basic Paint Ingredients this week we shall cover in more detail modern day Urethane Paint.

To recap on Urethane Paint Qualities:

• They are very versatile.
• Cover in just a few coats.
• Dry quickly.
• Can be wet sanded to repair minor defects or blemishes.
• Offer a very durable finish with maximum scratch, impact and ultraviolet light resistance.

Further urethane paint qualities include they dry much better when subjected to heat.

Professional auto painters frequently use paint booths equipped with heaters or infrared lamps to help urethane paint cure to its maximum strength in a short time.

At the factory, urethane paint jobs are baked at temperatures around 450 degrees Fahrenheit. This can be done because car bodies are bare and do not include any plastic pieces that would melt under those conditions.

This baking process further hardens paint pigments and additives and then helps them adhere to body surfaces better than ever before. Baked on factory finishes provide a solid base for repainting as long as the finish is properly prepared and scuffed.

Urethane Paint Instructions for the DIY Painter

For repaint jobs, you would generally use heaters or lamps at temperatures below 140 degrees Fahrenheit for about 30 minutes. Higher temperatures could damage sensitive engine computers or melt plastic assemblies.

You must be aware of the initial flash times of urethane paint before you begin using any force drying methods, including heat lamps.

Most paint products will need to rest for at least 15 minutes or more enabling the majority of solvent materials to evaporate. If you were to apply too much heat too soon, the solvents would evaporate too quickly, leaving behind blemishes.

If you do not have access to heat lamps, make sure that the environment that you allow your painted surfaces to dry in are as dust free as possible.

If automotive paint isn't left to dry in a clean, dust free environment it will be ruined by dust, dirt and debris that will stick to the wet painted surfaces.

Double check with the person who supplied you with your automotive paint the recommended stand alone drying time for the paint system that you intend to use.

Product information sheets list specific heat application times for particular temperature ranges.

Many top name paint manufacturers offer their own brands of urethane paint products. All of these companies believe they have the best products. Likewise, auto painters all have their own personal preferences.

However, just as with wax and polish brands, you can rarely get two auto enthusiasts to agree that one kind of urethane paint is better than all the rest. These decisions are based on all kinds of experiences.

It depends on your own unique experiences.

One painter may have applied a certain product over an incompatible base to cause a less than satisfactory result; another may have used the same product differently to arrive at a perfect finish with plenty of gloss and adhesion.

As much as users may disagree as to which brand is best, manufacturers are adamant about two things:

You must always use only those products included together as one paint system.

In other words, if you decide to apply Glasurit paint on your car, be sure to use Glasurit reducer, hardener, primer, sealer, cleaner and paint, etc. throughout the entire project.

Never mix those products with any other different brand. All products listed as part of a manufacturer's paint system are designed to be used together not mixed around.

Chemical bases and other important chemical combinations have been thoroughly tested and researched to give you the best results for your money.

Inadvertently mixing brands is asking for trouble. Should you mix brands, you are taking the risk that the new paint finish on your car or truck will wrinkle, craze, mottle and orange-peel or otherwise suffer damage that may be very difficult to repair.

Painters' second area of agreement applies to the use of all recommended personal safety equipment.

In addition to spraying paint in well-ventilated areas away from all sources of heat and flame, we insist that you wear respirators and strengthen that protection with a hood, rubber gloves and painter's coveralls.

These recommendations are clearly printed on paint product labels, which even go so far as to mention the kind of NIOSH (National Institute for Occupational Safety and Health) approved respirator to use when applying that particular material.

With paint manufacturers having to meet strict regulations and exacting product standards, it is quite safe to say that all of their products should perform as expected when properly mixed and applied.

To further ensure that the paint finish on your vehicle exhibits the deep shine and excellent adhesion expected; be absolutely certain you follow all recommended surface preparation instructions.

If you don't, the new paint you carefully spray onto your car's surface could dry to a separate film that would be easily peeled off in long sheets.

To refresh your knowledge on this topic, please refer to our series on 'Surface Preparation'.

We also cover in great detail, all aspects of surface preparation in How to Paint a Car - The System.

Surface Preparation is Paramount

One very important part of surface preparation to remember taking into account that baked-on urethane paint offers a durable, hard paint finish, is that new paint solvents might not penetrate the surface to guarantee quality adhesion.

Therefore, you will be required to scuff the paint with 180-220 grit sandpaper or a Scotch Brite pad before applying new paint so that the new paint can adhere to the old paint.

Again, to see a professional demonstration of an old paint surface being scuffed ready for the application of new paint materials please refer to How to Paint a Car - The System Part 1.

Information of this nature must be confirmed with your auto paint supply store member of staff for the specific job you are contemplating.

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That's all we have for you this week. Thank you very much for reading. We both hope this issue has been of valued interest to you.

COMING NEXT ISSUE: We cover in detail 'Special Effect Additives' such as Metallic and Pearl.

Please refer to our September 18th issue to read our introduction on Metallic and Pearlescent Paint ready for next weeks issue.

Happy Painting!

Chris Curwen & Dave Gage
www.LearnAutoPainting.com