Is it true that epoxy primer provides the best moisture barrier?

[bull]

I was down at my favorite body/paint supply store and ended up buying a quart of SEM 39308 Rust Seal to take care of the superficial rust in areas like the inner roof, under the dash, inside the sail panels, etc. The guy behind the counter is very knowledgable as far as I can tell and he recommended that I prime over the SEM stuff with an epoky primer to keep out moisture. I told him I had some other kinds of primers but he seemed fairly adamant that I should use epoxy and nothing else. Guess I didn't know the stuff was that good at keeping moisture out.

Is he correct in saying that it's really that good? If so, what is it about epoxy that makes it so much better than the other types of primer?

[Charger-Bodie]

Epoxy primer is the best for moisture seal,BUT the metal needs to be 100% clean.

[bull]

Epoxy primer is the best for moisture seal,BUT the metal needs to be 100% clean.

I was planning on putting the epoxy over the SEM sealer.

[Charger-Bodie]

Epoxy primer is the best for moisture seal,BUT the metal needs to be 100% clean.

I was planning on putting the epoxy over the SEM sealer.

Thats fine, Basically my point was do not put it over a  rusty surface.

[bull]

Epoxy primer is the best for moisture seal,BUT the metal needs to be 100% clean.

I was planning on putting the epoxy over the SEM sealer.

Thats fine, Basically my point was do not put it over a  rusty surface.

Wouldn't dream of it.

[lexxman]

So if you were to sandblaster then epoxy prime,that would be the best.But the problem remains is what to do about those small tight spots that are hard to get in?

[bull]

So if you were to sandblaster then epoxy prime,that would be the best.But the problem remains is what to do about those small tight spots that are hard to get in?

Short of dipping the car in a swimming pool full of epoxy I don't see how it's possible for anyone to get it all. Let's face it, you do what you can do and you let the rest go.

[motorcitydak]

What about using a self etching primer on the rusty parts?

[Troy]

I don't think you want to spray etching primer on anything rusty.

Troy

[motorcitydak]

http://www.eastwood.com/rust-solutions/treatment/eastwood-rust-converter-aerosol.html   

[69*F5*SE]

The Eastwood stuff is supposed to kill/convert the rust (I've never used it).  If the rust is dead you can then topcoat it with epoxy primer or Eastwood's Rust Encapsulater.  Etching primer won't kill rust or keep the metal from rusting.  Two products that I have used and know works is Picklex 20 (to kill rust) and ZeroRust.  Both very good products.  Read up on them.  Nothing beats clean bare steel and epoxy in my opinion but, Picklex 20 will keep your clean bare steel from rusting for a long time if you can't get to epoxy priming it right away.


http://picklex20.com/

http://zero-rust.com/

[Captain D]

Just so that I'm understanding everything okay...Right now, my Charger has been taken down to the metal and just has etching primer on it. The car will have the epoxy primer in a few months, but is having the etching primer on the car beneficial or a hindrance in rust prevention? In other words, should it be sanded off before the epoxy is applied or is it okay just to leave it on and go ahead with the epoxy on top of that?

Thank you,
Aaron

[69*F5*SE]

Not the most popular way but, you can apply the epoxy over the etch primer. Sand it good first.

[lexxman]

So if you were to sandblaster then epoxy prime,that would be the best.But the problem remains is what to do about those small tight spots that are hard to get in?

Short of dipping the car in a swimming pool full of epoxy I don't see how it's possible for anyone to get it all. Let's face it, you do what you can do and you let the rest go.

That's what I figured,but the plan is I think I'm going sandblaster,epoxy prime and go through with an undercoat gun full of picklex-20 or something in the tight spots.And after that hope for the best.

[69*F5*SE]

Remember, Picklex 20 must be top coated with epoxy primer or even ZeroRust etc.. No etch primer on top of Picklex 20.  ZeroRust is NOT for outer panels. ONLY backsides of panels or body interior and inside frame rails etc...

[b5blue]

I had some epoxy primer done and I can tell you if you are going to wait for paint, make sure it's thick enough to protect. Where my guy went light (it LOOKED OK) the rust started coming back pronto. Upon sanding and trying to treat it I found this out. For some reason unknown to me there were dots of rust in the thicker areas too...the whole thing is going to have to be reworked. So for 500.00 basically all I got was my side 1/4 and back windows sandblasted and some idea of what not to do!

[troy.70R/T]

The dots of rust were probably caused by water coming from the air suppy.

[b5blue]

So his line dryer was bad to....Thanks! He was just suppose to treat the bad areas (mainly the roof) and I told him exactly what to do (absolutely no bondo or fillers) I pulled the car a month later when I stopped by and saw what was happening was not what I said. Anyway I'm glad what I told him to do agrees with what you guys say, even if he didn't do it.   

[troy.70R/T]

I feel for you. I have had more than my share of bad experiances with body men. Seems like they will cut every corner and cover up everything just to avoid the work and save themselves time and money. If you are going to have someone else doing the body work on your car you NEED to stop by and check it out EVERY day.

[b5blue]

Exactly! Now that I relocated my #1 guy I'll be OK, but I'm going to do as much as I can myself beforehand with his guidance.(and everyone here!) I was on this topic like a bum on a Bologna sandwich!