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The Auto Painting Tips Newsletter
With Chris Curwen & Expert Auto Painter - Dave Gage (Car Cosmetics) August 28th, 2007 - Issue 18 In this issue:
For minor nicks and scratches, you can sometimes polish or buff them out as long as they are shallow enough exposing only paint at their deepest point. You will have to apply new paint if you can visibly see primer or the bare metal itself. To repair nicks, the use of touch-up paint is an easy and inexpensive method. You can easily attain small bottles of stock factory colors at auto body paint and supply stores and other auto parts outlets. All of these touch-up paints match the paint code on the vehicle's identification tag. You can use the small brush attached to the bottle to apply the paint with or alternatively any other fine paintbrush. It is crucial to cover nicks as soon as possible especially where bare metal is exposed. Oxidation will attack the bare metal where rust and corrosion will begin. This process will continue on regardless under the paint and ultimately cause the paint to peel off. In earlier times, applying dabs of clear fingernail polish to nicks in an effort to protect the bare metal from rust and corrosion was a common practice. Compared to small nicks, long deep scratches are a more serious problem. Although it is possible to use touch-up paint for minor scratches, touch-up paint is unable to provide efficient results when used in long strokes. Depending on the type and color of the paint finish, it may be a better idea to use an aerosol touch-up can or a regular spray paint gun and feather in new layers of fresh paint after carefully sanding scratches smooth. In 'How to Paint a Car - Part 1' a professional demonstrates how to repair vehicle bodywork that has suffered common 'key' damage extending over both the driver and passenger doors. Painting Panels Vehicles are composed of a number of separate sections and parts that are welded or bolted together, resulting in a single motorized unit. Professionals concerned with auto painting will refer to these parts as panels, such as quarter panels, door panels and rear body panels. If there is a lot of body collision damage or the paint job is a simple repaint, the painters have to spray complete panels in lieu of spraying specific spots. The type and style of the existing paint finish is pretty much crucial in determining whether to spot paint the panel or paint the entire panel. The size of the repair area and the ability to blend new paint into the surrounding body paint must also be considered. If a vehicle had minor dents scattered over its hood, it would be much easier and the finished look much more uniform and professional if the entire hood was completely prepared and painted all at one time. Likewise, it is true for other panels also. There are some situations where you can getaway with painting just parts of panels, as opposed to entire units. Lower panel sections up to featured grooves, ridges or trim lines on doors, wings or quarter panels are examples of this situation. With the arrival of base coat/clear coat paint systems', blending has more or less eliminated panel painting. Even with the availability of the correct paint code, the surface properly prepared and the paint applied perfectly, a panel painted separately will most likely not match the rest of the vehicle. Blending can also be achieved using single stage paint products; however, if you are not well-versed in the art of blending, a base coat/clear coat system is the best option for you to work with. Although it is true that the actual color of the repaired area may not match the adjacent panels exactly, the blend will create such an illusion that the affected area will not appear to have ever been damaged. On the other hand, you can easily spot two adjacent panels that have been painted separately. While painting panels, color blending and uniform paint feathering are of utmost importance. Your aim is to apply the paint in such a manner that no definite edges are visible. This will allow you to make the area appear as if it had never been repaired or repainted. This is the main reason why some single-panel repaint jobs require the adjacent panels on either side to be lightly sprayed with feather coats of paint; it makes them appear similar in color. You will see video footage of this technique being carried out including where to mask the bodywork to achieve this result in How to Paint a Car - Part 1 & 2. ******************************************************************************** Questions & Answers: Our first question this week comes from Yvon Benoit: Hello, All of your tips on how to auto paint are very helpful and I want to thank you. Could you tell me if I have to use hardener or thinner when I spray primer through my paint gun? The reason is I sand blasted all the parts under the hood like the inner fenders and the frame and a few other things. Ans: It depends on which type of primer you use. If 2k primer is used then hardener should be used, if it's air dry primer then thinner should be used. ******************************************************************************** Our second question comes from Clinto: Hi, I find your newsletters very interesting and helpful. I am 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'd 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? Ans: Firstly purchase around 3 liters of black 2k base coat. Then 1/2 a liter of red pearl and 1/2 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. ******************************************************************************** Our third question comes from Neil Croft: I've got hold of a 2 hp 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, Primer and Clear Coat from somewhere like eBay? What are the associated risks? c) How Much Primer, Color, Clear Coat will I need to paint my Alfa Romeo 156? How would I find this out? Ans: For part a) Neil please refer to our answer in Issue 13. There are many risks associated with mixing the various types/makes of paints. The best advice would be to buy all from the same manufacturer. 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. ******************************************************************************** Our fourth and final question this week comes from Brett Carthy: Hi, Can you tell me if my step-by-step plan here is OK? 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 gray primer, let it flash off properly then rub with 320's then 500's? I mask-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? Ans: 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. Etching primer is available in aerosol spray can form yes. 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 10/15 mins in between coats. All else is correct Brett, good luck! We hope this all help guys. ******************************************************************************** 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: The Complete Paint Job Happy Painting! Chris Curwen & Dave Gage www.LearnAutoPainting.com © 2007
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