Can I shoot epoxy primer as final coat of primer over my poly coat? Is it better to wait till after the 7 day window and sand it before topcoat or just topcoat without the extra sanding within the window? Is there any build characteristic to epoxy?
most epoxys you can use as a seal coat then paint. some may require a little reducer to thin out for a better laydown.
Yea, the can says to reduce using urethane reducer for a sealer, some say that epoxies don't sand nice though and I guess that's my major concern...
no sanding, lay it down like your painting, wait the 15-30 minutes what ever it calls for and spray your color.
I use PCL epoxy and always sand it. 400 for single stage 6or 8oo for BC CC. I find this to work the best.
If you reduce it and use it as a non-sanding sealer it does a good job of locking down the work below its surface so sanding scratches don't show up in your finish coat provided you let any high-build primer already on the surface sufficiently shrink down
I used SPI epoxy and thinned it as recommended above. Works great to show any flaws you missed and seal the work underneath.
Just did my car the other day. Epoxy was wet sanded with 600 after being sprayed over the high build. The wet sanding process was technically not needed but we wanted to ensure it would be flat. Top coat then went on followed by the clear process. I have had other cars with beautiful paint jobs that were done simply by reducing the epoxy and using as a sealer...they turned out great as well.
Hey, how thick is your polyester primer, and what's it covering? If you've layed down several thick coats to cover filler/metalwork, I'd let it sit a week or more. These coats of filler primer are gonna shrink, and you'll wanna block them lever BEFORE you seal the job with your reduced epoxy. Some preminum brands of epoxy have great build, but they're not ment to replace proper metal/prep work! " Humpty Dumpty was pushed "
I'd want my final coat of primer or sealer dead smooth, otherwise you are putting paint on an orange peal surface that will show in the right light when finished. Bob
You can use it wet on wet but if outside the window it needs keying, If you thinking of using it as a finish coat its not UV stable.
Agree.....I've done it both ways, but letting it dry and blocking it out makes a perfect surface to paint over. You have already sanded the car twenty times, what's one more? Also, as said above, make sure your coats under it are fully shrunken out.
For what it is worth, poly primer is not meant to be sealed and painted over. Poly primer is nothing more than sprayable body filler. You really should put down a couple coats of a regular primer surfacer, then sand it. Followed by sealer (if you are going to seal) then paint. You wouldn't seal and paint over body filler would you? I know guys do it, but that doesn't make it right. I have seen many failures do to this very subject.
The polyester is a hybrid primer from Evercoat, (Finish Sand) and can be topcoated as is, but I just wanted to seal it for safetys sake.
I really am not trying to be augmentative here. But polyester, is polyester. No where on that products data sheet does it say you can topcoat directly with paint, nor does it say you can't? If you could/should though I would think they would be putting that in print. Polyester by nature is a sponge and needs to be topcoated with a good primer surfacer. Just my $.02. Good luck to you. Glenn
I use the epoxy type primer for blocking with 220 then urethane primer with 320 which sprays like paint and leaves a nice finish with very little peal. Final coat of urethane primer sanded with 400. Use sealer for sure and paint.
I'm going by what my local Evercoat rep told me. Anyway I'm not topcoating it with paint, I'm epoxying it first.
Glenn your dead right about the Polyester, it soaks up moisture like a sponge, I won't use it these days as it causes to much microblistering unless its baked, If i was to use it I would sand dry and seal with Epoxy primer.
I live in dry mid-western Canada, I have bare metal sandblasted years ago and it still has no rust, I'm not worried about moisture problems....
Not to hi-jack this thread-but how long should you leave high fill urethane primer before you block out and top coat?
spray your epoxy sealer when you are completely finished with your body work, wait for it to flash, then start laying down your color. The sealer helps keep your body work from sucking up your color and causing blotchy areas.
I have done it like that,i mixed the epoxy 4-1-2 it claims to be a sealer when mixed that way,spray the color on an hour later,no sanding,wet on wet.however i have noticed that the top coat seems to haze out a bit,seems like it is sinking in?,might be something to watch out for.Harvey
Hey, Unless you're up against a hard deadline, I wouldn't block or prime or seal a high-build for several days or up to a week! All high builds shrink somewhat, and you don't want that going on under your top coat
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