End the debate. Whats best. Etch primer vs. Epoxy

[lyrikz]

I keep going back and forth between etching primer and epoxy.. I mean its literally a toss up on everyones opinion on what to use. My truck is bare metal right now. Im going to paint it with a basecoat/clearcoat paint job. I want to seal the metal, then use some kind of build primer, then do the paint job.

I have done a few full paint jobs before, but they all had factory paint that was in decent shape so i never had to use epoxy or etch primer. Just sealed the old paint and bc/cc away......

Whats best?

Etch primer

Epoxy

[SactoJim]

Both work fine, but the epoxy is probably the best bet for your use.

Most "etch" primers chemically adhere to the metal via acid in the primer. You'll find most etch primers won't allow any polyester type materials (filler, polyester primer) to be used over them due to adherence problems.

Epoxies stick mechanically to metal (via prepping the metal and they are just plain sticky). The up side is you can use polyster products over them. The other good thing about epoxies is they have more "body" than etch primers and have better filling characteristics.

[Fastfun]

I would go with epoxy. I like to use a system and that is if I choose PPG I like to go from the bottom to the top with one brand that are all compatable.

[lyrikz]

Originally Posted by Fastfun

I would go with epoxy. I like to use a system and that is if I choose PPG I like to go from the bottom to the top with one brand that are all compatable.

Thats what i plan on doing...

After viewing the poll results, gonna go with the epoxy....I also read that the epoxy's are somewhat thick and can almost do the job of a build primer, so i might be able to skip a coat....

[hugger6933]

Depending on the activator used you can paint over the e-prime without sanding, but most of the time some bodywork will be needed. That can go over the e-prime as well with just a little scuffing. Jim

[lyrikz]

Originally Posted by hugger6933

Depending on the activator used you can paint over the e-prime without sanding, but most of the time some bodywork will be needed. That can go over the e-prime as well with just a little scuffing. Jim

I have read quite a bit, and everyone says to remove that ecoating... Now, for inside body panesl and what not its fine.. But if your painting on an exterior with ecoating, you want to remove it....

Chop/cut/rebuild just had a segment on that...

[bad6772]

Etch Primers and Epoxy Primers are kinda different ...Etch has as jim pointed out has acids in them that kinda eats into the metal. , Etch is not really as out dated as everyone thinks and has its place...And Spies still wants it laid down over ANY of their product, where an Epoxy would not be used . and i am guessing that would go for Dupont too.For the most part,Etch can be used and should be used under most surfacer primers, and should just be (pissed on)...Not full coverage..Most if not all Epoxies will allow you to spray directly over bare metal....as Jim said they are just a very sticky product......But an Etch could be used, (pissed on) followed by a good surfacer primer and pretty much do the same thing.....I have done both and never had any issues either way..If it was me i would just do an Epoxy and forget about it...Less Products to buy


Edit:Just my 0.2......And most if not all polyester primers,have good etching and corrosion properties....But i would do an epoxy first,do your body work and the poly prime......

[56fleetside]

For the past 7-8 years we have not used etch at all here at the shop, we just strip em to metal clean the metal thoroughly then epoxy primer. Once primer cures a few days we block and do minor bodywork right on the epoxy(filler feathers much better to epoxy than metal) then poly prime whole thing with 3-4 coats. Once poly is cured a couple days we block with 180 and then spray 3-4 coats of high build urethane on followed by blocking with 400 then run over it with 800 and most of the time its ready for paint. I never paint straight over the poly tho....thats pretty much like spraying raw body filler

[lyrikz]

Originally Posted by bad6772

Etch Primers and Epoxy Primers are kinda different ...Etch has as jim pointed out has acids in them that kinda eats into the metal. , Etch is not really as out dated as everyone thinks and has its place...And Spies still wants it laid down over ANY of their product, where an Epoxy would not be used . and i am guessing that would go for Dupont too.For the most part,Etch can be used and should be used under most surfacer primers, and should just be (pissed on)...Not full coverage..Most if not all Epoxies will allow you to spray directly over bare metal....as Jim said they are just a very sticky product......But an Etch could be used, (pissed on) followed by a good surfacer primer and pretty much do the same thing.....I have done both and never had any issues either way..If it was me i would just do an Epoxy and forget about it...Less Products to buy


Edit:Just my 0.2......And most if not all polyester primers,have good etching and corrosion properties....But i would do an epoxy first,do your body work and the poly prime......

Originally Posted by 56fleetside

For the past 7-8 years we have not used etch at all here at the shop, we just strip em to metal clean the metal thoroughly then epoxy primer. Once primer cures a few days we block and do minor bodywork right on the epoxy(filler feathers much better to epoxy than metal) then poly prime whole thing with 3-4 coats. Once poly is cured a couple days we block with 180 and then spray 3-4 coats of high build urethane on followed by blocking with 400 then run over it with 800 and most of the time its ready for paint. I never paint straight over the poly tho....thats pretty much like spraying raw body filler

This poly that you two mention. Is that a build primer? Once you put that poly on, you recommend goig back over it with another primer before paint???

The epoxy im using is the dp90LX. If that matters.

[hugger6933]

The poly is also called 'high build primer'. Yes the poly prime would be next after the epoxy. I wolud spray 3 or 4 coats of poly then block sand like crazy. If you have some wavy panels a repeat may be needed. After that I would cosider a cuople coats of eurethane primer and possibly non-sanding sealer as well. After all of that you will be ready for a top coat [finally]. I would use a base coat-clear coat system. It is a lot of work. No wonder I am tired all the time. Just typing out the stepsand seeing the work in front of me makes me need a nap. Jim

[lyrikz]

Originally Posted by hugger6933

The poly is also called 'high build primer'. Yes the poly prime would be next after the epoxy. I wolud spray 3 or 4 coats of poly then block sand like crazy. If you have some wavy panels a repeat may be needed. After that I would cosider a cuople coats of eurethane primer and possibly non-sanding sealer as well. After all of that you will be ready for a top coat [finally]. I would use a base coat-clear coat system. It is a lot of work. No wonder I am tired all the time. Just typing out the stepsand seeing the work in front of me makes me need a nap. Jim

I have done a few bc/cc before but i have never wanted to do that build primer yet.. I know its alot of sanding.... Now that i have this truck, i want it glass smooth and i think that build primer is the way to go....

I will come back here when i start spraying that.. My metal is almost ready for some epoxy now.. Still have a bit of welding to do...

[lyrikz]

Originally Posted by hugger6933

The poly is also called 'high build primer'. Yes the poly prime would be next after the epoxy. I wolud spray 3 or 4 coats of poly then block sand like crazy. If you have some wavy panels a repeat may be needed. After that I would cosider a cuople coats of eurethane primer and possibly non-sanding sealer as well. After all of that you will be ready for a top coat [finally]. I would use a base coat-clear coat system. It is a lot of work. No wonder I am tired all the time. Just typing out the stepsand seeing the work in front of me makes me need a nap. Jim

I put some epoxy on the truck.. COOL STUFF.. Goes on really nice and is rock solid...
Question. Once i do ALL my body work and filler and what not and its all smooth, can i seal everything back up with epoxy before i paint or do i have to use a different primer???
So basically.
epoxy, body work, poli fill, smooth, epoxy, basecoat, clear coat.....

[Painter D]

I'm in the same boat as "bad6772" he hit the nail right on the head. I've used both epoxy and etch on different stuff ,and had good results with both. Do which ever one you are most comfortable with.