The Stovebolt Site Forums The Shop Area Paint and Body Shop clearcoats, primers - epoxy, primer surfacer, self-etching

What is the difference between epoxy primers and self-etching? I told my paint supply place what I wanted my primer to do, and he said I need a self-etching and a primer surfacer. The self-etching can go over bondo, but I can't put bondo over the self-etching. If the primer surfacer is 2k? (3 parts), what does the etching primer do? Also, I have another piece I used just the self-etching (didnt need surfacer) and I'm not sure if I can paint directly on top of it (it's been weeks).

Also, I'm about to spray clearcoat over my metallic paint. Anyone have any suggestions/tips on how to do it? I think I wait the flash time then spray the clear after spraying the paint. I was told by an Dupont rep. that I should then later buff the clear with a 3M yellow buffing pad. thank for any help!

Etching primer contains acid to adhere to the metal and retard corrosion. Epoxy can be shot directly over metal and does provide a good corrosion protection. If you want better, just apply the etch under the epoxy. Some brands of paint have a recommendation to apply etch over CURED plastic filler others don't. Applying a 2K urethane primer over an etch is my personal undercoat of choice. The urethane is a perfect surfacer for blocking and such and the etch provides the corrosion protection. Epoxy is very poor for surfaceing. If the item is not going to be surfaced then epoxy works great, like on a frame or a trailer.

Again, some brands have a recommendation to spray paint directly on top of the etch prime. Some say only certain paints.

What brand etch and paints are you using.

On the clear issue, check out this site ( http://www.autobodystore.com/cgi-bin/config.pl? )and get his video called "Painting 101" it is well worth the money. Refer to yor tech sheets on flash times. You generally wait from 20 minutes to a few hours to clear. there are some brands where you can wait up to a full week before clearing!

Yes, you can cut and buff the clear to a perfect finish.

[ 11-18-2001: Message edited by: MARTINSR ]

I'm using Transtar (www.transtarautotech.com) self-etching #6111 and I was using their primer surfacer, but I switched to the brand 5-star (www.autobodybrands.com) which is yellow. The 5star doesn't plug the sandpaper almost immediately like the Transtar surfacer did (unless sanded with water).

Thanks for the link. I'm going to find that message board on there very helpful too

Acid style etch primer are ment more for etching into galvanized or Aluiminum ,Epoxy primer are more for pourus materials such as sand blasted bare metal Etch will not stop corrision to any extent Try laying down a couple coats of epoxy before doing your filler work {Let primer dry over night} Then after your filler work is finished go over it with your 2K system