so everything went smooth and primer layed down. Now I'm painting fairings for a motorcycle and primed with acrylic sealer that i had left over from previous paintjob.
Sanded down with 400 then cleaned with soapy water. then wax and grease remover. Then the basecoat

Paint layed down great but after about 4 minutes or so I noticed cracks, more in some parts and none in others. I layed down the paint pretty thick like I always do and outside temp was 80 degrees using med reducer.
I have no idea why this happened. Seems like the paint didnt even stick to the primer. Never had this problem before or any problems in the past like this. Dont want to move forward without knowing what happened here.







the material I used





I woke up today and checked the parts overnight and some parts that were good had weird cracks like the paint shrunk. These parts were perfect when checked after an hour





A few fairing's I painted came out great though.

 

a little trouble shooting here: some of those cracks look deep enough that it could be in the fairing itself, not the primer.

Did you use any bondo/putty? If you did, did you let it dry completely and sand smooth before laying the sealer? sometimes when you use bondo/putty and lay it too thick, the top surface will dry but underneath it still takes longer to fully cure.

BUT if there is no cracks in your fairing or bondo, then is your primer sealer or base coat old? are your mixing ratios correct? How many coats of sealer are you spraying? IMO you dont need more than 2 coats. and sealer is not something you lay down thick. its a refinishing coat. Primer surfacer you can lay thick because you usually go back to sand it down and smooth it all out. but primer sealer should be sprayed like a basecoat. You're looking for coverage not film buildup.

Are you letting the primer sealer dry over night and then spraying basecoat? or are you spraying wet on wet? If you lay the primer sealer too thick, it too can dry on the surface but still not be fully cured underneath. And if u are letting it dry over night, you do have to come back the next day and wetsand it before applying basecoat.

are you letting each coat properly flash before you spray on the next coats?


when you go to re-do this, dont use any soapy water.
Starting from the base-- sand it down with your 400. rinse with water, then dry it off, then degrease it. Spray your primer sealer. (You dont need more than a coat or two since you've already once sealed it in the previous paintjob attempt.) Let it flash properly. depending on your weather or the instructions on the paint can, its typically 15 or so minutes. Then go to spray the basecoat and clearcoat. (or just basecoat if its singlestage). NO degreasing in between coats.

the wrinkled paint looks like the surface beneath it was not properly cleaned or sanded before you sprayed the base. It was either not degreased properly, or there was no chemical bond, or no mechanical bond, depending on how you prepped everything.

 

I let the sealer dry for days. and no bondo/putty. some parts came out great.
I let the basecoat flash between coats 14 minutes
I am told the sealer was junk and should have used a 2k.

 

so you sprayed sealer, let dry, then sanded it with 400 before applying basecoat?

or did you let it dry for a few days, then went straight to spraying basecoat? (without sanding the sealer)

theres no issue with letting the sealer dry. its mostly just a waste of time. its easier to just sand, spray sealer then basecoat all in one session.

IMO you'll usually ensure a better bond if you spray everything wet on wet (with flash time inbetween), and not letting anything cure over days before going for the next coat of something.

and again, your base coat shouldnt be sprayed heavy either. just a nice even thin coats (2-3 coats) that provides even coverage, not film build up. that sweet spot inbetween wet and dry. dont spray dry, dont spray heavy. Your base coat is your "appearance" coat. meaning its, just color. nothing more, nothing less. the clearcoat is what makes your basecoat pop, and gives protection.

 

yeah I sprayed sealer, let dry, then sanded it with 400 before applying basecoat
my base-coat is heavy enough to get full coverage. I spray fast

Im going to sand the imperfectiosn and lay another basecoat see what happens. Dont feel liek stripping it down and re priming/sealing

 

yeah u dont have to strip anything down unless the problem lies within your sealer or panel

but then again those big long cracks on your fairing looks like its coming from the sealer, unless your basecoat really is that thick




goodluck

 

to hot, to quick of a reducer, to much paint. I have had it happen to me before. You need to slow reducer and less paint. You are doing to need to sand down and restart, Make sure to feather your edges out and seal and blend your base coat in.

 

Yeah I already finished the basecoat. just sanded the cracks flat and primed with over the counter filler primer and then sanded it down and painted over it. came out perfect. Ran out of paint gonna get another pint to throw 1 more coat of paint on a few panels

motorcycle fairings are a bitch to paint compared to cars