Epoxy primer and body filler.

This topic seems to start more arguments than who shot first. Han or Greedo......
I have been encouraged to shoot my project with epxoy primer prior to doing the body/filler work. I have used epoxy over body filler before but never under it.
I have read about a 1000 different posts in regards to Filler first vs epoxy then filler. And it seems to be a matter of preference
Back when I did paint and body work for a living we never put filler over anything other than bare metal. But my expertise ends about circa 1982
So 2 questions:
1.If I use epoxy primer first how long should I let it "Cure" before applying the filler? Until all the solvents are gone or during the 7 day recoat period that most of them seem to have.
2. Can I use short strand fiberglass filler over the epoxy primer. And is the application time frame the same as filler?
Just trying to update my old brain and techniques.
Thanks as always.
Torchie.

Is epoxy sealer the same thing as primer ? I just talked to a man who used epoxy sealer on a job and he said he loved it .. the paint went on smooth and didnt have trouble with coverage .. I will try the sealer on my next paint job .

I'm not much for using bondo at all usually, but I rarely go for show car results. The few times I have gone that way were mostly done as you said with bondo first and then primer. Not but a year or two before those would show some separation from the steel on mine. The last time, I did it the other way and so far after several years, the results are still better. I'm thinking over time, going on top of the primer with the bondo may stay better. I don't forsee your work requiring anything very thick anyway...lol!
I have no answers for curing times but that should be on packaging or container. It would be different for varying kinds of finish.

Yankee Transplant said:

Is epoxy sealer the same thing as primer ? I just talked to a man who used epoxy sealer on a job and he said he loved it .. the paint went on smooth and didnt have trouble with coverage .. I will try the sealer on my next paint job .

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Some people use epoxy primer as a sealer before painting YT. I never have but I always shoot a sealer over my primer and under my Single stage color. Now a days it is a acrylic enamel sealer. Color covers better for sure.

smallfoot said:

I'm not much for using bondo at all usually, but I rarely go for show car results. The few times I have gone that way were mostly done as you said with bondo first and then primer. Not but a year or two before those would show some separation from the steel on mine. The last time, I did it the other way and so far after several years, the results are still better. I'm thinking over time, going on top of the primer with the bondo may stay better. I don't forsee your work requiring anything very thick anyway...lol!
I have no answers for curing times but that should be on packaging or container. It would be different for varying kinds of finish.

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The supposed purpose of the epoxy primer first is to act like a moisture barrier as well as locking everything thing down smallfoot. To keep the filler from doing exactly what you discribed. In some posts it has been said that if you apply the filler during the recoating window no scuffing of the primer is needed. Others claim that if you don't wait the filler stops the epoxy solvents from escaping.[S
Truthfully. In the all the time I have been using filler I have not had it pop off from bare metal in the time I have owned the cars or trucks. In Some cases that was 10 years. And notice that I call it filler, as BONDO was considered a dirty word by the craftsmen that taught me the trade.LOL
And besides. If I keep rolling the cab over on it's top I may need more than filler.
Torchie.

I'm not a body man. Every time I go to the autobody supplies/ paint store it seems thing have changed since the last time I went. I ask the guy behind the counter and he is very helpful. The last time I painted a truck I used 2 part epoxy primer sealer and was told I could use filler or 2 part spot putty over the primer sealer. I don't remember the proccedure. I would suggest you talk to who you are buying your supplies from and say what they say. I would imagine different products would have different proccesses. Good luck and let us know what stuff you used and the proccess.

I hear that on the bondo...the only instruction on body work I ever got was an old craftsman that still used lead....but his work was beautiful! When he got thru with his panel replacement or patch, it didn't need much lead. Did all his body work with a torch and a coat hanger and a pair of snips...

Go to this site and look around Torchie. http://www.southernpolyurethanes.com/

They have a forum for paint and body questions. The owner even puts his number on the site and says call him anytime! That's standing behind your product! I've heard nothing but good reviews for them, but haven't used them myself yet. I plan to the next paint job I do.

kenny c said:

I'm not a body man. Every time I go to the autobody supplies/ paint store it seems thing have changed since the last time I went. I ask the guy behind the counter and he is very helpful. The last time I painted a truck I used 2 part epoxy primer sealer and was told I could use filler or 2 part spot putty over the primer sealer. I don't remember the proccedure. I would suggest you talk to who you are buying your supplies from and say what they say. I would imagine different products would have different proccesses. Good luck and let us know what stuff you used and the proccess.

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The guy behind the counter is the one encouraging me to use the epoxy primer kenny. Talked with my bro who ran body shops for 30 years and he said that they never used epoxy primer and the whole "moisture" thing is just a marketing ploy from the people that sell epoxy primer.
It does seem as if it is geared more towards the DYI body/paint guys because it seems to take them much longer to get a car in paint.

Bamamav said:

Go to this site and look around Torchie. http://www.southernpolyurethanes.com/

They have a forum for paint and body questions. The owner even puts his number on the site and says call him anytime! That's standing behind your product! I've heard nothing but good reviews for them, but haven't used them myself yet. I plan to the next paint job I do.

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Thanks for the link Bama.
Much of what he says ties in to other threads I have read about using the filler during the 7 day recoat window with out having to scuff.
It may just boil down to my resources($$$) when the time comes. And it is getting here soon.
Torchie.

smallfoot said:

I hear that on the bondo...the only instruction on body work I ever got was an old craftsman that still used lead....but his work was beautiful! When he got thru with his panel replacement or patch, it didn't need much lead. Did all his body work with a torch and a coat hanger and a pair of snips...

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Sounds like the guys that taught me. And they taught me lead work as well. All gone now........
The original plan was to use lead on this project but that is out of my reach money wise for now. So in an effort to move forward I am back to using Premium Rage filler. Good stuff.
Torchie.

Torchie ,

I read 999 of the articles that you did and here is what I came up with about epoxy........ It is expensive but I thought it was worth it because ......

1] I did not take my body to bare metal . I had a combination of bare and old paint of unknown type and the epoxy will seal the old paint in so it does not lift later AND it also acts as an etching primer so you can eliminate that extra step [ and if you subtract the price of the etcher from the epoxy it's less costly.

2] The epoxy takes the " bondo" and grabs it ...even down to the feather edge.
You can start the body work the next day .

I then use a 2K " high build " primer to cover all the mistakes I did above ... man a good 2K can cover a lot !!! The next day after the 2K I sand with 400 grit...

This is where I use a 1K [ no mixing] sealer to make everything uniform and one color for the paint.... I wait a couple of hours after sealing with the 1K and then paint .

OK for the record this is my first "REAL" paint job and learned a lot ..it did not help that I used an Acrylic Enamel ..... what I really learned was .....
BASE COAT------ CLEAR COAT !!!! for my next paint job... I will post pictures when I get it all together next week

Oldog