what is the best way to deal with small rust pits on body? (pic)

djbartu · Sep 9, 2009

Below is a photo of the lower section of my right fender.

I stripped off the thick, poorly applied, paint and found no major rust or previous bodywork. The only flaw is the pitted metal as shown. I expect to find more similar areas on the lowers. What is the best way to repair / prep areas like this?

My plan was to lightly sandblast the affected area, fill, and prime.

Any suggestions?

Sauron67MM · Sep 9, 2009

It could also be, and most likely is, rusted behind it as well. Corrosion begins and festers between the inner brace and skin eventually popping out. Failure to remove the fender and address the potential problem will result in a repair failure.

Radcannon · Sep 9, 2009

Agreed. You need to pull the fender off and coat the back side with a sealer then you can do what you are talking about. It depends on how bad the pitting is you could also just primer it and block it down.

Icemans_67 · Sep 9, 2009

Do not do as Bubba did on mine, he pop riveted Aluminum over the rust with about 100 rivets the bondo over it, as pointed out kill the rust, the only means 100% sure that I know of is cut it out. My rust was coming from the inner support as pointed out as well. I'm currently welding in patch panels bought from Belair Bobs to address this issue. The only item I do not like about the patch is the corners come rippled and are not like the original, so I'm cutting them, straightening them and welding to make smooth like the orginal. Other than that they fit good. Just my 2 cents.

djbartu · Sep 9, 2009

Sauron67MM said:
It could also be, and most likely is, rusted behind it as well.

I had the fenders off when I replaced the engine. The back sides are coated with a lot of undercoating. I'll strip that off to see what I find.

KevinW · Sep 9, 2009

I think glass beading would work better (and more gentle) on the surface rust on the sheet metal and sand blast the rear support.

casey69z · Sep 9, 2009

Yes the big question is what does the back side look like. As said above they have a rust problem between the support and the backside. So you could be just seeing the tip of the iceberg. Both of my fenders had rust holes at this spot.

Here is how I fixed them.
Here is how bad the rust was. Note the piece is laying ontop and from the other side but you get the idea.

cut it out, cleaned off rust, treated rust pits on support with phosphoric acid ( black areas)
The support is thicker metal so it was still in good shape strength wise.

epoxy primer ( pass side pic)

made patch from 18ga sheet

worked the metal to put in bends and fit it ( pass side pic)

welded, ground and finished.. ready for filler coat ( pass side pic)
weld beads only about a 1/16". I left a little instead of flush to have stronger repair.

Denvervet · Sep 9, 2009

touche Casey and great job on the fab. Rust doesn't often occur in one isolated area...not for 40 years anyway. Clean both sides with media blast a see what you got. If you shortcut it you'll be kicking your own arse for years to come just to save a few hours of work.

what is the best way to deal with small rust pits on body? (pic)

djbartu

Sauron67MM

Radcannon

Icemans_67

djbartu

KevinW

casey69z

Denvervet

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