I just sprayed Nason epoxy on a fender and did not allow enough flash time between the three coats. There are about a dozen small craters. Can I fill these with metal glaze, block the fender, apply another light coat of epoxy and then spray color? Or do I have to sand it all off and start over?
09-13-2012 02:01 AM
When did they appear? Was it some time after flash time or right away?
If it's right away that could be contaminants.
I never had solvent pop on Epoxy but if it's a dozen small holes why not block it out and spot in some epoxy? It's not much more work and you wouldn't have to wonder about that area and how it will hold up. If it's a reaction and not solvent pop then sanding it down will just give you the same problem again cause it will re-reveal that stubborn area that gave you problems to begin with.
09-13-2012 06:22 AM
You have a 24 hour window with Nason for recoat and cross linking of the chemical components (at 72*, less if higher if I recall) - it's probably gone now. My thoughts are that you possibly have polish/wax or other chemical (WD-40? Teflon spray? etc?) problems rather then solvent pop. I've only used the Nason epoxy once - disliked it. Resand with 320-400 wet, removing the craters and recoat.
09-13-2012 06:52 PM
I sanded the fender down until the craters were gone, wiped with wax and grease remover, sprayed one nice even coat of nason epoxy primer and the craters are back in what looks to be the same locations! What am I dealing with and how do I fix it? The rest of the car has been no problem, just this one fender. Is there any way to fix this other than a can of aircraft stripper and a putty knife?
09-13-2012 07:55 PM
Originally Posted by kmoses
wiped with wax and grease remover
If you take the wax and grease rmover out of the loop and use Ajax on a grey scuff pad and a clean water rinse, odds are you won't see the fisheyes again.
09-13-2012 08:56 PM
So sand again, clean with Ajax and grey scuff pad, rinse well with water, when dry spray with primer. Is it the wax and grease remover causing the problem?
09-13-2012 09:18 PM
It can cause more problems than it solves..
This time just "dust" on a "ground" or mist coat at first and then once it is showing good behavior put it on wetter etc...
no primer if it's nice and flat
10-03-2012 11:31 PM
Be careful when using ajax,comet etc. Be sure and rinse WELL these products tend to leave a film behind and if you dont rinse it you will have delamination problems, Wax and grease or a good waterbase cleaner will do a great job.
10-04-2012 12:13 PM
I've had the same problem with Nason Epoxy primer and what Milo said is what I've had to do to resolve it. Since then, I just use SPI epoxy primer.
10-08-2012 07:55 PM
I sanded the fender until the craters were gone starting with 220 and finishing with 500 wet. Using a grey 3M pad and Ajax I washed the fender and then rinsed with water twice and let it air dry overnight. This afternoon I sprayed both fenders with Nason Ful-Thane Holly Red and other than a few dust nibs they were glassy smooth and crater free! Thank you for all the help.
10-08-2012 10:25 PM
The problem with wax & grease remover is people do not know how to use it. It must not be allowed to evaporate dry, it must be wiped dry. FWIW Ajax and Comet are two completely different products. Comet would not be advisable to use in prep work IMHO.