The Perfect Paint Job 06/2013 Edition

AndyK

****
Staff member
The Perfect Paint Job

06/2013​
Our goal is to accomplish a paint job that has a strong foundation, maximum gloss and will last for many years. This type of painting is not practical for the everyday production body shop but it will serve you when you do your next restoration or a street rod job. We are going with the assumption that the metal or fiberglass has been stripped of all paint.

All bare metals and aluminum should have 80 grit DA scratches.


Spraying primers:


Bare metal is always best cleaned with 700-1 Waterborne Wax and Grease Remover and 710 Wax and Grease Remover, then let it sit 30-60 minutes before applying the epoxy!

After first reading our Epoxy Tech Sheet mix enough SPI Epoxy Primer to spray 2-3 wet coats over the entire car. Spray one wet coat and let flash about 30 minutes then apply a second wet coat. Let the epoxy sit overnight then apply body filler or glazing putty over the epoxy. Let the epoxy sit 24-48 hours before applying polyester primer.

It’s not necessary to sand the epoxy before applying the fillers (within the first 7 days of spraying epoxy) as they will bite into the epoxy and feather great. When you have finished sanding all of the bodywork you are likely to have some bare metal spots from sanding. Spray one wet coat of epoxy over all filler spots and over any bare metal spots. Now let the vehicle set overnight.

The next day you can start spraying the 2K primer over the epoxy. Once again, it is not necessary to scuff or sand the epoxy before applying primer. The most important thing to remember at this point is spray one wet coat of 2K primer and let it sit for 10 minutes before applying the second coat. Follow this procedure between all coats of 2K Primer. This step when abused messes up more paint finishes than anything else! When all of the primer blocking and any necessary primer repairs are finished it’s always best to use the epoxy as a sealer. Mix up enough epoxy to go around the car with one wet coat and adding a double shot glass of SPI 885 Urethane Reducer per quart. Let the epoxy sit for 30 minutes. Stir one more time and strain. Spray one full wet coat of epoxy over the entire car. The epoxy should sit for 6 hours before spraying basecoat or the next option is let it sit over night and wet sand the epoxy with 400-800 then spray the base.

Spraying the basecoat:


Next to rushing the 2K primer, rushing the basecoat is the second cause for the final gloss and depth of a paint job to look bad. It’s very important to use the slowest urethane reducer in your basecoat that you can get away with regardless of outside temperature. Just allow enough extra time for the basecoat to flash off and dry. The difference between a very slow grade and medium grade reducer will show up in the final gloss. The slower grade reducer also has better solvency and will give you far better adhesion. Spray the first coat and let it totally dry before spraying the second coat. It’s best to wait 30-45 minutes between coats of base. Always wait 45 minutes between base colors that contain a lot of black pigment.

If your basecoat isn’t perfect:

After two coats of base the vehicle should sit overnight, and then do any minor wet sanding with 800-1500 grit sandpaper to remove any orange peel or trash. Apply the next two coats with 45 minutes of flash time in between coats. Some colors will require additional coats. If this is the case always wait 45 minutes between coats. Let the basecoat sit overnight. A word of caution: There are 2-4 basecoats types that cannot be sanded or you will lose adhesion so avoid those basecoats. Check with your basecoat manufacturer.

Clear Option 1: Applying the clear in a single day


The following day tack off the vehicle, then apply a wet coat of SPI Universal Clear and let the first coat of clear sit 30 minutes. Spray the second wet coat of clear and let it sit 30 minutes. Let the clear sit for 30 minutes before applying each additional coat as well. Normally 4-5 coats of clear are applied during this process. Then proceed with normal wet sanding and buffing when you are ready.

Clear Option 2: Layering multiple coats of clear over multiple days:


Spray 3-4 coats of clear waiting exactly 30 minutes between coats. Do not bake! You can set the booth at 80°-90° and leave it on if you wish. The next day, if possible, let the car sit in the daylight/sun all day regardless of air temperature as all we want is UV light. The following day or anytime after, wet sand the car with any grit between 400-800 and put it back in the sun for at least a half a day; a full day would be better. Clean the car with 700 waterborne wax and grease remover, then clean it with 710 wax and grease remover. Do it carefully as anything left behind will destroy the paint job. Let it sit 45-60 minutes then apply 3-4 more coats of clear waiting 30 minutes in between coats.

DO NOT BAKE!
The booth heat can be set at 80°-90° if you wish.

Anytime after the day of last spraying the car give the car one full day in sun. Wet sand the next day with the grits of your choice, pull the car out for at least a half day in sun then buff it at your leisure. It’s advisable for black, dark blue and dark green paint jobs to have an extra day in the sun with any of the above steps, as blacks dry/release solvents slower and this step will prevent the black from showing fine scratches and it will help you get rid of swirl marks when buffing.

Wait a long time before waxing:

NEVER wax one of these multiple coat jobs for at least six months or you will run the risk of delamination down the road. You can use detail spray to make the bugs wash off easier and to make drying easier as these products are designed to breathe.
 
As we do every year before we print the catalog, we go through and fine tune all the tech sheets, the reason is as I receive tech calls all year long, I do listen and use those conversations to fine tune the tech sheets.

A major change you may see this year in the perfect paint job is where we recommend cleaning bare metal with the 700 first and then 710 next, I almost made this change three years ago because some of our shops were using this process but decided to listen more and to find out there are many shops doing this.

You will also notice the major changes in the epoxy sheet, right down to the statement of if you want to use rust converters buy the rust converter paint system, not SPI.

Also the statement about cold weather, if you can't control the heat, don't spray the epoxy.
 
Do the 80 grit da scratches and new cleaning steps apply to fiberglass as well as metal?
 
Fiberglass can be 180 or 80, I usually have both in different areas when I do one.

Damn, I knew it and it never fails, we leave something out.
 
Would you be willing to make a procedure for production shops? If only for on-line?
 
Kent, I don't know if I'm qualified to do that, I talk to 10-15 of our production painters a day and they all do there repairs different.
 
Just a best practice write up might be beneficial. Make a baseline procedure then we can adapt as needed. Not everyone wants a show car but want a daily driver to look good.

You are our trusted advisor. You wouldn't have to put up with me as often!
 
The most important thing to remember at this point is spray one wet coat of 2K primer and let it sit for 10 minutes before applying the second coat. Follow this procedure between all coats of 2K Primer. This step when abused messes up more paint finishes than anything else!
Next to rushing the 2K primer, rushing the basecoat is the second cause for the final gloss and depth of a paint job to look bad.
This is a little confusing. First, let sit for 10 minutes before second coat of 2k. Next statement implies rushing the 2k causes problems. I think I would be rushing to spray a whole car in 10 minutes, and refill the gun, etc. Is the 10 minute statement an exact, or no less? For example, is 30-60 minutes between coats of 2k going to be a problem?
 
MX442;29098 said:
This is a little confusing. First, let sit for 10 minutes before second coat of 2k. Next statement implies rushing the 2k causes problems. I think I would be rushing to spray a whole car in 10 minutes, and refill the gun, etc. Is the 10 minute statement an exact, or no less? For example, is 30-60 minutes between coats of 2k going to be a problem?

Not a problem but after 5-10 minutes with that product, its not hurting or helping, there are just a couple of solvent we want out in this time, the rest come out very slow.
 
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