Bondo Showing Through Red Primer

So in order to get the car on the road this summer we are going to run with red primer.

When I spray primer over bondo patches you can see the bondo through the primer. Not in that it is transparent, but the texture of the filler.

It will look goofy.

Any ideas?

 

bondo sucks up a lot of primer, you need to use a high fill primer first

 

Sealer or primer surfacer...thicker stuff

 

well you didn't sand the bondo fine enuff. The very least i will prime over is 120 grit. You can sand what you have with 120grit or 180 grit. put a tracer coat on it first. sand her smooth and put on three more coats of primer, then you'll be all good

 

Sand it?

 

Nope that's not the problem. Smooth as a baby's bottom.

 

what 36-3window said.

 

As stated, filler is pourous and the primer will sink into it and continue to do so for some time. This is called staining. Using a sealer will counteract this when its time for topcoat. As for now, it is basic rule to spot prime bodyworked areas with 2 coats before you shoot the overall panel. I usually do 2 coats on the filler and 3 overall. It gives me enough build to really block the bodyworked areas as well as help keep it from staining.

 

How many coats did you spray? I usually spray 3-5 wet coats of high build on top of filler. One thin coat won't hide the filler.

 

I know exactly what you are talking about. ---and the fix. Sand your bondo to a point where the surface is fairly smooth--as in 180 grit paper sanding. You want a bit of "tooth" left in it. Prime 3 wet coats.--Yes, you will see the filler because of texture issues. Let it set for a day or two. Go back and sand again with #280 grit paper over the entire area. This will give a uniform finish and texture to the bondo'ed area and to the surrounding non-bondo'ed area. Then reshoot the primer. You will not see the bondo area then.

 

prime then get some flat paint,primer is porous,unless it's an epoxy, so moisture will get to the metal and rust will prevail, flat paint should kill the flashing of the bondo.

 

I'd say I've never done bodywork only to the bondo stage and considered it done. the primer is a part of it too. I like high build primer. 3 coats - guide coat and block.

how else do you know you got it right?

 

2k high build

 

You aren't using rattle can are you? Ever try dura glass?

 

A roller leaves a smoother surface - actuall y done in some shops that don't have enough booth space and it's legal in many restricted areas where they cannot spray outside a booth.

 

I just want to make it through the summer. Then teardown blast and proper finish.

 

alll you have is spary a few coats of prime over the bondo let it dry a day to dry. then skuff and reprime the next and it ll be fine

 

Are you using spray bombs??????????????
Lacquer based?
If so, try using "real" primer.
You can get passable primer from an autobody store...high build. I've recently seen a catalyzed primer available in a spray can, even better!

 

well here's the bad part, lacquer primer is "solvent soluble" meaning that it can dry for a hundred years, you put any topcoat on it ,or any solvent, it gets soft again. so if you do poor bodywork and try to fill it with primer it will shrink on you. also lacquer primer will absorb water like a sponge and hang on to it ,causing rust. you can do quality body work and use lacquer primer and get away with it, but it has to be done right, and right away.

 

Thanks guys. I picked up some high build and it worked perfectly.

I can always count on HAMB.