Barry, the one booth at NACE that I spent more time than any other was Evercoats. I had writen notes to ask them, I went back to the booth many times, I even got one of the R&D techs card so I could call him about a test I am going to do and he wanted to hear the outcome.

These guys were very open to discuss on and off the record all of my (sometimes bizarre) questions about the products.

I have seen this question brought up many times "Epoxy or bare metal?" To qualify my comments as being nonpartial, I have NEVER in my life applied epoxy prior to filler, NEVER. So I am one of the bare metal guys. Not because I think it is better, but because I have simply never had the push behind me to do it doing collision repair every day. It does take a little more time that we never seem to have.

That being said, I think it is the right way to do it (epoxy first that is) just by the science of it.

People have said, "The filler manufacturer (Evercoat for instance) says BARE METAL, they do NOT say epoxy". To which I reply "They can't endorse a brand of epoxy for fear of alienating all the other epoxy companies and they can't say ANY epoxy because there are junk products out there". It is that simple, they can't say use SPI epoxy, NO PPG, DuPont, etc jobber would have Evercoat on their shelf! They would loose BIG numbers in sales. They can't say "Any" epoxy because they would get bit by failures when people put Evercoat filler over some junk low grade epoxy and be blamed for it.

I posed these thoughts to the Evercoat guys and they agreed. A quality epoxy primer is best. They just can't put it in the tech sheets. Bare metal is "good enough" and is "safe" that is why they say it. NOW, if you look at the tech sheet for EVERCOAT polyester putties it says to apply it over "OEM Cured finishes" and "Two part primers". So they are opening the door there a little.

Brian

Everything they said is true! There is no reason to recommend the procedure.
This is not a procedure for their production body shops that is probably 90%
of their business.

If they did, look what happen here bad application of some sort and guess who they would call? Fiberglass evercoat.

It would be nice if Fibreglass-Evercoat would offer an epoxy primer, then we might see them make a recommendation.

Everyone I want to thank you for the great and heated discussions. I'm sorry if I caused such a ruckus with the link on the test. But I'm re-sanding my weld line and trying to get out any remaining surface rust and then shooting my epoxy primer tomorrow. The high here in SA is supposed to be in the low 80's. Thanks again and if you see a big cloud of smoke from the south its me laying down that epoxy.

MP

MP, you say you are trying to get any remaining surface rust out before you spray epoxy. If you have two pieces of metal, lets say 2 inches long, one inch wide, welded all around the outside edges, and there was some rust in between them, without any 3m spray weld on it, just bare metal with the rust. If you sprayed two good coats of epoxy on both sides, would it still rust, rust a little or not at all.

Now add filler to that like dura glas, then two more coats of epoxy, it should be airtight? Will it rust.

Thanks Rob

http://webpages.charter.net/2manitowoc

thats kinda where I'm at. My weld line is on the floor of my cab so I'm having to clean both sides of the weld line due to me not being able to get back to it. everything I've read here about rust is once is starts unless you chemically stop it or remove it will continue to rust. So even though I'm going to do the exact same prep procedure : 2 coats epoxy, then filler then 2 coats epoxy and I'm using the Evercoat Rage filler I'm going to make sure all rust is gone. Man I can't tell you how sorry I am for not immediately getting back to those weld lines to cover them. This "re-cleaning" the weld line is a pain in the you know what. But to answer you question, I think once rust starts unless its treated with a rust-encapsulator or removal of the rust all together, the rust will eventually run its course. Now this is just what I have read and based off of all the work I'm having to do to get that weld line clean. I hope this helps and if it does not do a search for "rust" on this board, there is some very knowledgeable people on this forum
good luck.

satexas as right, you need to get rid of the rust first before epoxy. Epoxy won't help if put over rust, may slow it down a little by sealing, but it will come back. They make products like rust convertors and acid based products, but I am not too confident in them and believe the best way is to get rid of it however you can, sandblasting to replacing the piece if neccessary. When you have two pieces of metal overlapping each other this is often a trouble spot, and may just compound the problem.

Oxygen is one of the three parts that has to be present for rust to occur, can oxygen get through several coats of epoxy, I don't have a clue, but just guessing I wouldn't think it could. Anybody else on here that could enhance us on this subject.
Rob
http://webpages.charter.net/2manitowoc

Here is a discussion of rust Hope the link works..
From experience in the marine and industrial environments to keep a piece of steel from rusting we work to keep it sealed with a good quality material..the epoxies have been proven to be the best for this...

It is up to the applicator to get a good even coating applied to the metal and to get any edges or overlaps sealed like for example a lap joint..

Doing a good job of a lap joint like say in a floor pan, first a fellow would try his best to get a good tite joint. then using a brush work the epoxy into the seam until no gaps are remaining in the seal of the joint, that is if any are there at all. that depends on the quality of the metal work.

Following that shoot 2 wet coats of epoxy primer and then you are good to go.. this procedure is about the best I know of in actual practice..

OMT

__________________
I would rather make it work than make it popular..And if it does not work it will not be popular..

A young man a couple of years fresh out of body shop told me exactly the same thing as you just did, on how to apply it, thats two for two, I'm convinced thats the way to go, nice tubing bender
Rob
http://webpages.charter.net/2manitowoc

Well I did after all the DVD watching, form reading and question asking. I laid down my first ever line of sprayed epoxy(2 coats that is). The one thing I have to say is thanks everyone for your help. I must say it took an awful lot of prep work to get those weld lines ready etc. For a full 20 minutes of priming. But heck I painted my first line of paint and it was cool. I wore the special breathing mask and goggles and man getting the gun set up with the proper filter and PSI setting etc.. seemed to take for ever. But finally I got to mixing my mp170 and mp175 and thought wait 2 to 1 and you know the rest. Put it in my HVLP with two strainers when filling my gun and then POOF. I was laying my weld line to sleep, the part that was tough was the underside of the truck, I watched the paintucation DVD and he shows gun technique but I could not get it right but I got the primer down. I must admit it looks really shinny now but I'm sure it's going to look dull after it sits tonight. Can't wait to see what it looks like in the morning(eeewww). One question I have is after all the test info. How can I make sure before I put in my filler the epoxy primer has good adhesion to the metal? Well once again thanks everyone this was a trip and I can't wait to try more.

MP

ohh no sa, sounds like your already hooked on it. Be prepared for many more hours of tedious sanding and sore arms and fingers in years to come.
I must admit that I still sneak out to the garage and take a peak at something I've painted when things go well. Maybe it sort of a reward for all the work that you did to get to that point, and know that you are just about done and have to admire the fruit of your labor. Heck I even still peak in the booth at work at the end of the day when something I did bodywork on was painted that day. Gun technique will come with time, then everythings natural and you automatically make adjustments when needed. As far as testing your adhesion. Like mentioned before epoxy is not fully cured for a week or so, I guess you could take a fingernail or something after this time and try scraping it. I am not sure of answer on this, but sure someone will have it for you.

If you prepped the metal surface with some good sanding scratches and it was cleaned well there will be no adhesion problems with the epoxy. The only times (few) I have ever had problems with epoxy adhesion was when there was poor prep prior to it's application. After a week in good temps the epoxy will be hard as a rock. I tried the epoxy you're using years ago and yes it will lose the gloss as is cures, some epoxies don't and will stay somewhat shiny after it is cured. You can start applying filler the next day and there's no need to worry at all about epoxy adhesion if your prep work was good. Epoxy rules IMO, you just can't beat the durability it offers. If you run out of the MP primer consider switching over to SPI as it's much higher quality IMO and priced right.

I was looking over my steps on prepping for paint and I show epoxy then filler then sand, but should I lightly sand the primer before I put on the filler? I looked at the P-sheet and it does not mention that. I wen to evercoat to review their sheet for Rage product and it gave not mention on what to do. Any advice?

MP

If you apply the filler within a week you'll be fine without scuffing, after that when the epoxy has reached full cure a simple scuff with sandpaper or a red scotchbrite is all that's needed, I've used a red scotchbrite for years. Some prefer a light scuff with 180 grit.