when you epoxy prime your car, 2 coats and plan to start doing the body filler in a couple should you scuff it up with 80 grit,in the tech sheets it dont say

You should prep the area the same way you would any other repair area. If it's major you should strip it to bare metal for metal straightening but, if its minor filling roughing it up for adhesion is fine, JOHN

You don't need to use 80 grit, 180 or 220 will suffice. 80 grit will cut through the epoxy for sure, compromising the performance of the epoxy primer. After your filler work is done apply two more coats of epoxy before applying any primer surfacer. You will have some normal cut throughs on the epoxy as the filler is sanded and it is up to you if you want to apply more epoxy to these areas before applying additional filler if needed. I've used this method since about 90 and have seen excellent results, no adhesion problems, no corrosion issues, and no shrinkage as the epoxy is a solvent barrier after full cure.

Is it OK to apply body filler over un-sanded DPLF Epoxy Primer? Tech sheet says it must cure for 24 hours before doing body work but does not say to sand the DPLF before appling the filler. I have my 70 doors primed in DP74LF and let them cure for a week. Just cleaned with DX330 and applied filler over some small door dings and block sanded everything. Looks real straight and sanded fine. Have to re-prime some areas that went to bare metal though. What do ya think "sevtchevelle"?????? Am I ok with this?

ttt

thanks guys

I believe the sheet says wiat 1hr before appling filler over DPLF. Thats NOT something I would do, I would wait atleast 3 days.
Epoxy is a slow curing product if you apply filler too soon it WILL peel right off, as the still escaping solvents loosen the filler.
Being that its late Oct and you are from NJ, Id wait longer then 24 hrs

Scuff the DPLF with 180 or even a red scuff pad, 180 would be the best. A good quality filler like Evercoat's Rage Gold will stick to anyhting!!!

Id feel better if you had some type of mechancial adhesion between the filler and epoxy

"Epoxy is a slow curing product"-

How about applying fill/sand over DP, is there a reason it shouldn't be done after say a 30 min "flash"? I am getting ready to spray and having to wait a few days to apply surfacer over the DP would really be a problem.

((("Epoxy is a slow curing product"-

How about applying fill/sand over DP, is there a reason it shouldn't be done after say a 30 min "flash"? I am getting ready to spray and having to wait a few days to apply surfacer over the DP would really be a problem.)))

If in doubt, just scuff the epoxy with a red scotchbrite pad prior to spraying the primer surfacer. I'm sure it would be OK to just apply the primer but it only takes a few minutes to scuff the epoxy just in case. Bob

Originally posted by baddbob71:
If in doubt, just scuff the epoxy with a red scotchbrite pad prior to spraying the primer surfacer. I'm sure it would be OK to just apply the primer but it only takes a few minutes to scuff the epoxy just in case. Bob Scuff the epoxy while it's still wet? I was planning on 3 coats epoxy (5 min flash) and 3 coats surfacer (after waiting 30 min for epoxy to tack). If I were to scuff the epoxy after 30 minutes it would make a mess.

Sorry, I misunderstood, no problem with applying surfacer over DP after a 1/2 hour flash time.

Appling primer over 30 min old DPLF is no problem, its just when you apply filler over it too soon.
You might want to double check the flash times. Depending on the hardner used the flash time varies. I believe 401 is 30 mins and 402 is 60 mins.