Danza

Hello everyone,

Hoped to get some quick answeres from the pros/experienced amateurs regarding proper technique when appying fillers over bare metal.

The area in question is a welded hole from a windshield washer squirter. The hole was filled using a steel backing plate, then the recessed area was filled with weld. The current surface is slightly lower than the surrounding metal requiring the use of body filler to create a smooth surface.

I have seen several methods that amateurs have used to apply the filler, but no pros so I would like to get some opinions.

<U>First Method</U>

Apply a fiberglass filler such as Evercoat Everglass to the bare metal.

After this is applied/sanded, polyester filler such as Evercoat Rage Xtreme can be applied to smooth out the surface.

The final filler coat is applied using a glaze such as Evercoat Metal Glaze.

Block sanding is done with the aid of a guide coat primer like SEM 38203

Finish with light coats of acid self etching primer

<U>Second Method</U>

Use a metal wash like BASF RM 801 to clean the area that got welded.

Use an epoxy primer (not acid) to coat the bare metal then let sit for a day or so.

Use Evercoat Rage Xtreme.....same method as above from this point.


The main question here seems to be the level of corrosion resistance you give the surface while taking into account the inability of most fillers to be applied over most primers.

I'm pretty certain filler cannot be applied over an acid etch, but apparently can be applied over the epoxy primer? This epoxy primer would provide the corrosion resistance. In the first method does the fiberglass filler provide corrosion resistance?


Thanks for all of your help in advance

Car in question:

swappedcx

Products like "all metal" are DESIGNED to be applied directly to bare raw metal surfaces. Most other fillers I spray a epoxy primer first, then apply the filler over top. Of course many will come in and say you can apply the filler to bare steel...which I have also done with no ill effects.

Here is what I would do if it were me.
Clean the area. Spray with epoxy primer. Apply filler. If bare metal shows through, spray with epoxy after all body work is done. If you have a rattle can of Acid etch primer (usually in a purple can, I believe it says ACID #8 or something is what we use) and your bare metal spot is smaller than a quarter, you can use that rattle can acid etch in place of re spraying epoxy. This is a 100% acceptable practice. Then hit it over with primer surfacer. If you have no bare spots shoot with a primer surfacer. Sand, base, clear, done.

Danza

thanks for the help.

I was getting a bit confused as I'm pretty sure the evercoat products say to apply over bare metal but I'd like this to hold up indefinately w/ as little chance of corrosion as possible.

7andaswitchblade

I use a roll on epoxy primer (no need to mask the car, worry about over spray, put it in a booth) and then sand with 80 grit once cured. Then I would use something like evercoat glazing putty.

Honestly though, I have used filler over bare metal many times with no corrosion issues. It seems like 50 percent of jobs are done like that still, and it used to be the way everyone did it. If you are building a show car though, why risk it I guess. Use the epoxy first and make sure you give everything plenty of time to cure, you don't want any shrinking or swelling after the paint is on there.

Danza

thanks for the help/input guys.

Seems like fillers like everglass/duraglass are safe to use over epoxy primer even though evercoat says use over bare metal?

swappedcx

You really cant go wrong either way. Applying it over bare metal will not give you corrosion issues that you should worry about, and applying over epoxy is just another "just incase" step.