Suprised nobody mentioned this. JB Weld is great stuff, but it takes 24 hrs. to set up & is hard to sand down. Try USC All Metal filler instead. It's aluminum based, mixes with a hardener, applies like bondo, & sets up in a few minutes. Best part - it's waterproof & will not soak up water like bondo. Excellent for areas that may get chips in the paint, like rocker panels. I've used it a lot, & only use plastic fillers for finish surfacing. It's expensive, about $40 a quart, but worth it.

Thank you for the idea. Seems like it would work with the holes. For now until I paint the car I just put a tiny piece of aluminum tape with adhesive backing over the holes to keep out water. I remembered that I did that on a hole in the siding of a house once and it was still there when i moved out.

Either way you are going to have to paint over the repair, and because of that, I would recommend welding them shut. Bondo over gaps in bodywork is a huge no-no, say hello to problems in a few years regardless of how well you did the "repair". Try to avoid using a dremel tool for cutting down welds, they will skip no matter how much of an iron grip you have, use a 90 degree die grinder with an 80 grit sanding pad installed. Another alternative is to use a cut off wheel to dress the welds, but doing that will leave gouges in the metal regardless of how lightly you press.

Simply tape thick cardboard around the area you are going to weld on, once you have a large enough border to catch large bits of spatter, use whatever you can find to cover the rest of your car. If it's possible to reach in, try to have someone hold a thick piece of scrap copper behind the holes in order to make pooling the weld easier, it will also help prevent warpage.

Edited May 20, 201410 yr by The Janitor

I would take the door out of the car, strip all parts away, strip the paint of, and weld in a new plate, bondo and respray then. Or maybe even easier: get a good second hand door and respray to match color.

The Janitor, bartsscooterservice,

Thanks for the great info, sounds like welding is the way to go. For now I am driving the car as a daily driver, great fun.

good thread. My z has a few holes i want to get welded up.

mirror holes (going fender mirrors) https://scontent-b-sjc.xx.fbcdn.net/hphotos-xpa1/t1.0-9/1601120_10151996840348557_887137795_n.jpg

rear panel rust spots https://scontent-b-sjc.xx.fbcdn.net/hphotos-xpa1/t1.0-9/q80/s720x720/1554614_10152009839468557_955095027_n.jpg

(id like to just cut a flat sheet to cut and weld in place).

On my FC rx7, i actually filled in the spoiler and emblem holes with rage gold body filler (alot better than bondo brand fillers). I think i put jb weld stick on the back side of the holes for support. It held up a few years (recently gave the car away as a shell).

I don't have a welder, but that is something I want to get into.

Edit: That solder trick looks pretty good in my opinion. Do that, shave it down, than a skim coat of body filler on top of it should be good.

Edited May 31, 201410 yr by Hypertek

What about using all metal filler from the backside on the holes where you can get to the backside? I have my fenders off and all my interior panels out. I want to fill all the holes left over from removing the trim strips. My thinking was to put filler on from the backside so it could be built up a little thicker since it wont be seen, and sand it smooth from the outside. Seems like if it was slightly thicker that it would have less chances of cracking out later? Anyone try this or see any issues with it?