I am trying to finish the prep work to epoxy prime my 68 coupe. Replaced rear lower quarters so I have some body filler to put on not to mention a little on the quarters. Questions are, do I prime first then start working the filler or the other way around, will metal prep hurt the filler?. And how do you repair the drip rails that have rusted out? It just in the front forward part of the drip rail in both sides about 2 inches long hole. Thanks

 

Any bare metal must be primed with your primer/sealer before body fillers. If there is any rust sand blast/wire brush or grind it down until youno longersee the discoloration or it will return.There are some fiberglass type fillers that last much better than Bondo. Almost as good as metal. The drip rail you can either make a patch piece or cut a pair off a donor car.

 

you dont have to use primer before filler. if you do make sure to use an epoxy filler not the 2k sandable kind

 

why cant you use the 2K sandable kind under the bondo?

 

you can i just like to seal it with the epoxy,since it is water proof. I also like to use the epoxy again over the filler before the 2k to minimize bleed through

 

Couple questions here since I am a nood at this as well.

What is 2k?

After media blaster you seal the whole car with an epoxy primer correct? Can you use filler right over the primer or do you sand away the primer to bare metal to use filler? Am I reading this right? I always thought that body filler need to be on bare metal. At least that whats I have been told.

 

2k= 2parts basically a catalized primer compared to lacquer which is a 1k that has no activator.

you can epoxy prime and wipe filler directly over the epoxy normally with in a certain time frame(have to check the tech sheets) sometimes if your within the window you actually dont even have to sand the primer.

filler is applied over bare metal in most cases you want at the minimum a of an 80grit sand paper "tooth" for it to bite into or a 36 grit. always prime at leas two coat of 2k primer over filler. i like to spray it on one day let it fully cure then sand the next morning then reprime and wait to the next day. it aids in reducing sand scratch swelling.

 

You guys don't use a metal prep of some kind (phosphoric acid) on the bare metal before you start spraying? Oxidation can and willstart when the metal is exposed, even though you can't see it.

 

Best thing for you to do is find a shop local that does restoration not collision work and ask them what to do. If you bondo over bare metal you are making maybe a five year repair. The sealing primers that have zinc are the best base coat, but they are getting harder to find and you need to be careful spraying them.