Body Repair - Rust Holes

If you can't get to it, you probably can't get rid of the 'cancer' hiding back there. It has been my experience that, unless you get it all, there is no use in dirtdobbering Bondo or fiberglass on a rotten spot.

You don't need to access the back as long as you can seal against water. No water, no rust. (Rusting of the back from condensation will continue but is relatively slow. Or, if you can get access from inside the trunk, coat with motor oil.) Any rust on the outer surface that would prevent a good bond to the underlying steel needs to be removed though. This is really the critical step. Bondo is preferred--less messy and more sandable.

Neither. Here's how you can do everything from the outside - and do it right.

1. Cut away any rusty metal around the hole. If you leave any rusty metal, it'll only get worse very soon. Sand or wire brush the paint away from the hole about 1".

1. Make a steel patch roughly 1/2" bigger than the hole & either weld a thin rod right in the middle of it or drive a long skinny screw in the center of it.

2. Wiggle the patch panel through your hole and use the rod/screw to hold it *behind and against the body sheet metal* while you weld the patch panel in place. You can also epoxy it in place, but finishing can be a PITA because epoxy will be harder then the metal around it. If you use epoxy make SURE you don't have any globs above the external metal surface or you'll spend a LOT of time filing it down when it's really-really hard unless you have a Dremel and a lot of patience. You also have to hold your metal patch firmly in place until the epoxy sets up - about 7 minutes.

• IMHO, JBWeld is the best epoxy out there, available at most any auto parts store. I've even used it to repair a broken exhaust manifold. Costs about .

** If you can't weld (you'll need a MIG or oxy/acy welder - arc welders are WAY too hot for sheet metal), have any welding shop do the job for you - it's a lot cheaper than you might think. Because this is really a small job, you might get it done for as little as $5 - $10 if they're not busy. *** If you're epoxying the patch, let it fully cure/harden overnight before continuing.

1. Remove the rod/screw from the middle of your patch.

2. Only use as much bondo as you need to level the patch.

1. Prime, sand & paint the patched area.

2. Feel real good about doing it right - have a beverage of choice.

This way, everything is repaired with steel and bondo is only used for leveling - as it should. Also, any time you use anything but metal behind a repair, the mesh (or whatever) can actually hold water against your patch and it'll rust out in short order. You should only use fiberglass repairs on fiberglass bodies. Bondo-mesh repairs have a habit of falling out in one big chunk the first time you slam a door real hard. Those mesh/bondo repair kits are the biggest waste of money you'll ever see - they just don't last.

Good luck, - Jeff G

Thanks guys. Sounds like JBweld and Bondo is the way to go. A long screw and washer/nut thru a wood bridge should do the trick for curing. I hear you on getting out as much of the rusty metal as possible. Will probably use rust reformer on what's left. Have to patch body panel perforation to get through inspection around here.

The other thing to do is quirt lots of Fisholene or Shell Enis oil into the cavity after you have glued on the patch. Magic stuf fto stop rust comeing through the inside of sills from condensation geoff