Ok guys this is my first attempt at really painting and i'm running into some problems. I'm using a harbor freight hvlp gun with a 1.4 tip, craftsman 6hp 30 gallon compressor and i've run both 25 and 40 psi at the gun. Using the ppg shopline bc/cc system and i've used dupli-color rattle can primer, which i think may be causing some problems but some things with it still don't make sense.

I started out by painting my ls6 intake and front bumper support i used the same method i'm using for my engine bay, dupli color rattle can primer and then bc/cc over that and both of those turned out pretty good for the first pieces i've painted.

Now on to the problem i'm having, after shooting one coat of base once again over the rattle can primer under the hood i had an excessive amount of trash so i put up some plastic and a couple fans inside my garage to try and cut down on debris and it did help out. So i scuffed the first coat with a red scrotch brite pad and shot 3 more coats, on the third coat i had one small place about the size of your finger nail that started to wrinkle up. So i sanded down the area reprimed and tried to blend it in and since then the problem has only gotten worse and started to attack other areas of the paint. Here is the small spot that started this
And now i've got real problems, after scuffing the basecoat and putting on two light coats and a heavy coat i've got this:
However where the original wrinkle was it now looks ok
So do you think this is a direct result from the laquer based primer reacting with the bc/cc? Although no problems on the intake or bumper support, i didn't realize this could be a problem until i already had the engine bay primed and ready to go. I've went through about three different mixtures of paint, 1 pint and 2 quarts mixed at different times is that a problem? Also is there such a thing as too many basecoats? Everything i've gathered so far it seems to be some type of chemical reaction from something and trying to make the paint lift, oh and by the way i've been breaking down the gun and cleaning with paint thinner and then running a bit of reducer through it. Sorry for the long post guys but any help would be greatly appreciated.

Thanks, Scott

 

Yes the Laquer based primer is what caused the results in your pictures. You should really uses the primer (Type) PPG recommends. You may find that the other parts may start to blister later (hopefully not).. Roger

 

Yep, rattle can primer is the culprit, seen it all the time in the shop...that is why it is banned! You should also be sealing the areas before base coating for best results. Hard to spend the extra money for a do it your selfer though, sealers are just as expensive as top coats. Chuck

 

the primer may be cheap but it should work. the main issue u are having is due to excessive coats. i recommend you start over. If you end up using the same primer make sure its dry completely and when you apply the base do very light coats. Its less of a shock to the other materials you are using. I would never recommend rattle can primer though. But the wrinkle is from too much base. try lighter coats and more time to dry. You have like a 24hr flash time with base. You can tell its too thick because of how shiny it is. Its not like clear. Lighter coats and more time in between

 

Im with bandit here, looks like you hosed it on a little too thick and it started lifting.

 

Yup!! Like was said^^ too much too fast without proper flash time. The primer should be laid on in light coats as well. The reducers in the paint are what are reacting with the prior coats.

 

That is also caused by too much time between coats and not enough time for fully cured . .

 

Ok guys thanks, i do believe i wasn't waiting long enough and putting it on to thick. I'm gonna try and sand the wrinkles out and lay on some light coats with about 30min or so in between coats.

 

its definately going to take some trial and error for your first time. Try a lil finesse and good luck. Hope you project comes out good.

 

There is some good info in this thread.

OP,

Is there any reason you decided to go with the rattle can primer instead of the Omni primer? A quart of it isn't very much. Reduce it 10% and you can use it as a sealer if you want.

Also with that 1.4 you will be putting out a lot of product. I tend to use that size for filler primer. Not saying that it won't work just becareful when you spray it so it won't run especially your first coat of clear. If the first coat of clear runs to much it can take the base with it which means you have to sand it all back down. You can let the last coat of base dry a little longer to help prevent this. Keep us updated.

Also did you use wax and grease remover on bay before you sprayed it. When I first saw it I thought there might have been grease under the primer but I would say the guys that have posted so far are probably right.

I use comet cleaner with a green scotch brite pad on engine bays before I spray them. The comet helps break up any grease and combined with the scotch brite pad helps scuff the paint/metal so the primer/sealer will stick better.

 

I went with rattle can primer because at the time i didn't know any better, after i had everything sprayed then i ran across some info online about it being laquer based and could possibly cause some problems, most of the old school guys say it's fine and they been doing it that way for years and the other half of people disagree with doing it this way. So i figured i would go ahead with it and see what happened, ecspecially after i had no issues with my intake or bumper support. Yes i did wipe/clean everything before the primer was sprayed.

 

Finally got those wrinkles knocked down and resprayed and then last night sprayed a tack coat and 2 pretty wet coats of clear. Just debating on whether or not to try and knock down some of the orange peel and then respray another 2-3 coats or leave as is. What do you guys think?

 

Did you end up repriming with a catalyzed primer or did you sand out the lifted areas and shoot more rattle can?

 

I sanded the wrinkles out and applied more basecoat very lightly with 25-30 minutes between coats.

 

That looks much better, nice work. Patience is all it took. Chuck

 

looks good