Epoxy Primer before or after body filler thoughts….

[Moparfiend]

Whats your opinion and rationale?

 

[snakeoil24]

Before, Seals the steel and all Bonding putty is porous.

 

[eldubb440]

both...... epoxy is all I use

that being said, there are quality "direct to metal" fillers (which I also use) that can be used on metal or over epoxy

I like to seal up my bare metal with epoxy right away..........not so much to fill over it; just to hold the metal from rusting, because things always take longer than they should

 

[Sahara]

I paint for a living, and I don’t pretend to know everything, but my experience is that primer sticks best to metal, and everything else sticks best to primer. Has worked well for me for forty years.

 

[Moparfiend]

Thanks its unanimous so far! All good points gents!

 

[eldubb440]

I paint for a living, and I don’t pretend to know everything, but my experience is that primer sticks best to metal, and everything else sticks best to primer. Has worked well for me for forty years.

I actually scratch my bare metal with 80 by hand before priming as a DA tends to "polish"...... years ago, I used 80 on a da and the primer didn't bite..... only seen it once, but once was enough

 

[JimKueneman]

Epoxy first. It is what seals the metal. Filler on metal can get moisture behind it (think rust pinholes). Of course here in Az you would likely never notice! Make sure you follow any recommendations by the epoxy manufacturer on windows or sanding grit for adhesion for the filler over epoxy. My current project.

 

[Moparfiend]

Epoxy first. It is what seals the metal. Filler on metal can get moisture behind it (think rust pinholes). Of course here in Az you would likely never notice! Make sure you follow any recommendations by the epoxy manufacturer on windows or sanding grit for adhesion for the filler over epoxy. My current project.

View attachment 1246983 View attachment 1246984

Jim nice proj. Is that a Duster? What coating are we looking at? I see a gloss type finish there.

 

[snakeoil24]

Epoxy first. It is what seals the metal. Filler on metal can get moisture behind it (think rust pinholes). Of course here in Az you would likely never notice! Make sure you follow any recommendations by the epoxy manufacturer on windows or sanding grit for adhesion for the filler over epoxy. My current project.

View attachment 1246983 View attachment 1246984

Beautiful job

 

[JimKueneman]

Jim nice proj. Is that a Duster? What coating are we looking at? I see a gloss type finish there.

66 Valiant. Motobase yellow base and SPI Universal Clear following Barrys “Perfect Paint Job” directions

 

[Mackman]

I seal everything with epoxy, then sandable primer before filler.

 

[Moparnocar]

both...... epoxy is all I use

that being said, there are quality "direct to metal" fillers (which I also use) that can be used on metal or over epoxy

I like to seal up my bare metal with epoxy right away..........not so much to fill over it; just to hold the metal from rusting, because things always take longer than they should

How is the feathering of filler over epoxy?

 

[JimKueneman]

How is the feathering of filler over epoxy?

Not sure what the question is? If you sand through the epoxy when working the filler you just spritz on a bit more
Epoxy to cover it up and more filler. It won’t be a linear process trust me!

 

[barbee6043]

Both. Epoxy, then filler, then epoxy, then high build urethane primer, block, sealer, topcoat/
Or just rattle can it!!!!

 

[Cranky]

A friend of mine had a Ferd pickup where the paint came of the top of the hood and cab and started rusting so he sanding it and sprayed a couple of coats of epoxy primer on it.....it lasted for years.

 

[Moparnocar]

Not sure what the question is? If you sand through the epoxy when working the filler you just spritz on a bit more
Epoxy to cover it up and more filler. It won’t be a linear process trust me!

Epoxy I've used has been rock hard, hard to feather/sand. So you epoxy, Bondo, sand Bondo, filler primer over that? I've had problems feather edging over epoxy

 

[Moparnocar]

I seal everything with epoxy, then sandable primer before filler.

When do you " block" it out? After sandable primer?

 

[eldubb440]

Epoxy I've used has been rock hard, hard to feather/sand. So you epoxy, Bondo, sand Bondo, filler primer over that? I've had problems feather edging over epoxy

Southern poly epoxy sands pretty nice and is all I use start to finish (also reasonably priced)......I agree, some epoxies are almost impossible to sand, but not all

also, I like body fill over 24 grit grind with direct to metal filler.......I epoxy my panel first, it lays in the lows and pits after I rough it up with the 24; but I actually prefer the rough metal for applying filler

I get my bodywork close and bury it with a couple epoxy coats, board and/or block sand it out with 120/180 dry, fine tune anything with some glaze and reprime (with epoxy)......ready to sand and paint

 

[Mackman]

Most epoxy primers I have used were not sandable. If you sand into them, you run the risk of your topcoat shrinking into it. I had flaws in a paint job show up weeks after it was shot, where I had sanded into the epoxy primer in spots. Now, if I have filler or spot icing to add, I shoot a layer of sandable primer/ filler first.

 

[JimKueneman]

Epoxy I've used has been rock hard, hard to feather/sand. So you epoxy, Bondo, sand Bondo, filler primer over that? I've had problems feather edging over epoxy

SPI epoxy sands like 2k. Many of us SPI users will use the epoxy as our 2k with poly. The Valiant is just poly and epoxy. Make a strong chip resistant base