Body Work Help

[Snuze]

I know we have a few Oppos who do their own body work, so I'm hoping one of you can help me out.

I'm de-trimming my Volvo fender (I will eventually de-trim the whole car) which means I have about seven 1/4" diameter holes to fill in. My plan is to cut some little circles out of scrap steel and weld them in place. But then I will have weld bead that I need to grind down flush with the rest of the fender.

What is the best way to do this and the best tool to use? I also rolled the fender lip and had to do a bit of welding there. I cleaned it up with an angle grinder and then a dremel. It came out okay, but it was really tedious because I had to be super careful with the grinder. I feel like there has to be a better way.

So any tips, advice, thoughts, comments, questions, concerns, good stories, or bad jokes?

Tommykaira ZZII for your time. Its a neat little prototype from early 2000s that I recently discovered. It was to be a boutique supercar built by a partnership of Japanese tuning houses. Its big claim to fame was a mid-ship RB26DETT for propulsion. Cool!

[sony1492]

@snuze angle grinder with a flapdisc works pretty well, probably use a finer grits disc around 80 to not accidentally grind too deep.

[CoolMinivan.......Nobody]

@snuze Something like this:
With some of these small Roloc discs:
Works excellent for smoothing out small weld areas.

Then a light glaze of filler and blocking to ensure it's straight.

[Italia]

@snuze I'm no body man but I paint most the stuff I weld and am a big fan of flap discs.

[CobraJoe]

@italia Seconded for flap discs!

I'm not much for body work, but I do a lot of welding and grinding in my garage, and I love the Benchmark Abrasives flap discs, they're cheap and they last a long time. Plus, you can get them in very high grits (up to 320 in the interleaf design). That should slow down cutting and leave a good finish.

What kind of welder would you use to fill those holes? 1/4 in seems like a very small hole to try and use a patch for. If you're using Mig, you could tack weld each hole shut. Give it a little tack on one side of the hole, let it cool down, then tack right next to it. Do that a few times, and the hole should be sealed and ready for grinding.

Disclaimer: I haven't done body work in a very long time, and I wasn't very good at it.

[Italia]

@cobrajoe that's how I'd patch a quarter inch hole as well. If you have access to the back you can hold a plate there made out of metal that doesn't mig like copper or something to make it easier too.

[sn4cktimes]

@italia said in Body Work Help:

@cobrajoe that's how I'd patch a quarter inch hole as well. If you have access to the back you can hold a plate there made out of metal that doesn't mig like copper or something to make it easier too.

As a welder this would be my attack method for a hole that small. Copper, brass, aluminium with all work.
-Brass works well for small stuff as it doesn’t gas off too much, and moves heat pretty well; on bigger welds it can incorporate into the weld though. On small stuff it holds up well to many uses. Don’t confuse it with bronze, and don’t use bronze.

-Copper is better for moving heat but pits out badly, tends not to mix into the weld zone at all really. Good for quite a few uses.

-Aluminum tends to gas off and leave the most mess to clean, but is the easiest to clean off abrasively. It degrades very easily but you can also get away with gauge thickness bits of it and just chuck them out. Can often get off cuts around fab shops. You’ll have a harder time getting off-cuts of brass/copper as their recycling return pay out is higher; so shops won’t want to hand out freebies.

All 3 will work for a hole that size. Even three stacked pennies might work okay. Just don’t hold them with your hand... that heat with transfer FAST.

[A Former User]

@snuze how big are the holes? Can't you just run the welder a little cold and bridge the gap and then fill in the holes with wire? Less fuss. A flap wheel on an angle grinder is the easiest way. Or a little die grinder wheel. I actually have a cordless die grinder but I've never used it with a sanding disc.

[VincentMalamute]

This bodywork tip just popped on imgur (unmute): https://imgur.com/gallery/CID1BaK

[MM54]

As someone who has killed two die grinders in the past month doing sheet metal work, I recommend a right angle die grinder with a 2" roloc wheel and 60 grit discs, for most any metal work. If you need to take off more material than you can grind into shape with that, you need a cutoff wheel on an angle grinder.

Edit: If you don't have compressed air... I dunno, maybe a much finer grit flap disc on an angle grinder, like 80-120ish? I have 40s and 60s and I'm pretty sure they'd make a hole in 18ga steel by the time the weld was flush.

[Darkbrador]

As mentioned above, Rolocs are your friends here. They're flexible and come in all sorts of grit, to get at the weld gently not do any/more damage.

Angle grinders (with an arbor adapter) work like a charm if you don't have an air compressor and all the hose-ry that comes with it.