Paint issues

[Brenner]

I have been attempting to bring my projects appearance from the 80's into the 2000's and am in the process of paint work. I have body panels from 4 different bikes and have repaired, sanded, prepped, and primer, to the best of my ability in attempt to do a decent job. My questions goes out to those who have repainted their bikes and or performed panel repair and repaint. How many of you have found a chemical reaction between the original factory primer and today's solvents in basecoat? I have a total of four pieces of the bike that are reacting and the remaining panels are not affected. The panels are off different bikes so I can't rule out it is only from one bike. My concern is a slow lifting reaction that occurs while the paint is flashing and does not show while wet. It looks like I will have to strip the panel completely down to the plastic to remedy this concern and I realize there is not much else that I can do but I just thought I would ask if anyone else has run into this?

[Flyinfool]

Is it your primer that is reacting with the factory paint that is under it, or is it the base coat (first color coat) that is reacting with the primer that you used?

[Brenner]

It looks to be my basecoat reacting with the factory primer under the factory paint believe it or not. I have used high fill primer with no reaction and water sanded and laid the paint no problem. An hour after still good but two hours or so later it starts to lift as the base coat flashes off. Now this is only on certain parts of the panels which is what I find weird but I attribute that to were the sanding broke through the original paint seal. I had more than one part do this and have already remedied a couple by sanding down past the factory primer and recoating with my primer and laying the paint a little heavier in attempt to hide the issue . So far success with some panels but one fairing side is bad and I know it is a bad area that will show any imperfection. Going to try to water sand and cut it down again today. I hate the idea of sanding it all down to the plastic but it might be a last resort and I am using professional automotive products not no cheap rattle can job. Again it lays well and starts to flash real nice but while drying starts to lift the old primer and paint down to the plastic.

[slowrollwv]

Some of the parts may be painted with lacquer and others with enamel.

[Daveand Barbie]

You might spray a coat of sealer on before priming.

[Marcarl]

I've had some of the issues where you speak of as well. Can't really say what causes it, or which part is reacting with which part. What I found to be helpful was to change primers and then wait a full day before using any topcoat.

[Brenner]

I suppose you are right. I am glad to fear that I am not the only one that had this issue. I looked the problem parts over since my last post and again the lifting was down right to the plastic and when peeled I had the factory original primer and paint in my hand. I have had no problem with my primers (2K high solids) and same manufacturer base coats with previous projects and on other parts and sad to say I do let them dry and still have this result but I will just cut it down again and water sand then primer/sealer let dry then base, same as before. I will win but I am getting a little antsy as I do not know if this bike will be ready for my April 08 deadline when I will have to insure it as my insurance runs out on the virago then. I am overly particular and trying to cover all my bases at once which can be overwhelming at times. If worse comes to worse I will insure my Harley for a month or so until the Venture is ready and the substitute the venture in for the rest of the insurance term. I need to learn the venture so I can confidently pass my M2 exit course in October with it. People tell me to take my Virago as it will be easier but I have to sell it to pay for this years insurance, money is a little tight but I still want to play. My priorities are straight but some times I need to wheel and deal to afford the luxuries. I will find the income I need and when it comes it will come fast.

[turtle]

Some plastic parts are hard to get primers to lock out . Ifeel you had any cut through the base solve goes through causing the problem. Prime with a water base primer and make sure you have enough fill build even though you can't see a UT through if you don't have enough film build it still can happen.

[Oldseadog]

I had the same problem when I tried to repaint a couple of parts. I blamed the problem on the fact I was painting with Lacquer over enamel, and, the temperature wasn't the best for painting. I ended up removing all the original and starting from bare plastic.

[Brenner]

Thanks guys, I have a heated shop and am using base clear. Yup I think my issues are due to cutting through the factory paint when repairing the panels. I am not a professional but can make my projects look a lot nicer than a rattle can job. I will attempt to remedy this problem today and as mentioned earlier believe it to be due to the factory primer/ sealant but with patience I should be able to establish a positive result. Patience- that is one thing I am learning to build. Wish me luck...

[utadventure]

Brenner-

 

My comments come from the miniscule amount of painting I've done.

 

Primer is designed to seal the surface before applying paint. In metal it prevents it from rusting until you apply the paint, in wood or drywall it dries quickly to prevent the material from absorbing the final paint thus showing the wood grain or joints. ABS plastic doesn't have either issue.

 

When I painted my '86, I repaired the damage and prepped it by using a wax remover. Wax or polish will cause the paint to bubble or frog-eye as it dries. Next was to spray the surface with a binding agent, this is made to help the paint adhere to the plastic. Next is to paint and then clear coat. Some painters recommend to paint with clear coat first to even out the surface of minor variations.

 

I've painted four bikes using this process and never used primer and while the jobs show my amateur abilities, I haven't had any other issues with the adhering or finish.

 

Good luck!!