epoxy primer Q

[61K10]

I have some pieces that were blasted to bare metal and shot with epoxy primer. question is i have urethane high build primer. how do i prepare the epoxy primer to use the urethane? epoxy will be aged. so what to do? just scuff the epoxy?--------- thanks in adv---------

[CMACDONALD1]

I would scuff for sure. I would probably use the red scotch brite pad myself.

[hugger6933]

The only primer I am speaking to is the PPG brand as that is all I use. The P sheet on it will tell you after 7 days you will need to sand with 220 grit paper and recoat with one to two coats of epoxy primer. After that sets then you can go on with the high build. After recoating you can coat right upon the epoxy within 24 hours after the 24 scuff with a red scotchbrite pad ,after the 24 and before the 7 day mark. hope that is clear didn't sleep and my mind is not clear. good luck and happy sanding

[61K10]

thanks for the reply-----I didn't use ppg but your directions are probably close. will look up p sheet. so why use epoxy? any other primer thats more home--painter friendly?

[hugger6933]

Yes there are more home painter frindly primers like good ol grey laquer primer. It can stay mixed up for almost ever just shake the gun when ready to use. However the laquer type primer has been used for decades it comes nowhere close to the protection of the metal that the epoxy primer does. It adheres to the panel kinda like melting on a plastic coating ,and that is exactly what it feels and looks like. So you can have easy and cheap or good and expensive. And the two never mix

[zicc1835]

ihadnt picked up aspray gun in 30 years ....i used the E in my garage at home and was very pleased with the results .....i was that lacquer guy 30 years ago)

Originally Posted by hugger6933

Yes there are more home painter frindly primers like good ol grey laquer primer. It can stay mixed up for almost ever just shake the gun when ready to use. However the laquer type primer has been used for decades it comes nowhere close to the protection of the metal that the epoxy primer does. It adheres to the panel kinda like melting on a plastic coating ,and that is exactly what it feels and looks like. So you can have easy and cheap or good and expensive. And the two never mix

[CC69Rat]

From what I have read there is a chemical bonding process that really needs to happen between your Epoxy and first pass of Urethane primer / high build. You want to prime your Epoxy within the 1min - 7 max day window to make sure you get a good bond. anything beyond 7 days can cause the primer to lift over time .. (just what I was told)

If you go beyond the 7 day work window, just knock it back down (not all the way off) with 220 / Red scotch brite and re-coat with Epoxy x2. Wait 1 day, then Urethane primer. .. but not longer than 7 days.

I really think knocking the first Epoxy off is just to keep the film build down, but of course it helps with the bonding concept too.

[61K10]

thanks for the reply's---received a -mail reply from the paint store teck line---after 7 days to sand and re-shoot with one coat of epoxy sand (scuff) 7 day window--shoot the urethane primer (which has it's own directions) so if blasting to bare metal have both materials ready and body work done---yah right-------

[CC69Rat]

I usually lay the epoxy pretty thin and use multiple coats so my 2x is probably = 1 avg coat. But yes, I agree. It's tough for me to get the Epoxy down, do the body work and prime all in that 7 day window .. (cause I don't do it every day. Weekends only when the wife allows me out of my cage.)