Each end of the floor pan brace has 4 spot welds to the inner rocker. I can't get a drill flat/square. I'm sure someone else has encountered this. Here's a pic illustrating things. I know for the new brace I can drill from the other side but imagine this is attached under the car

I'm thinking I need to go at this with the die grinder and either grinding stones or carbide bits. I hate the metal slivers from a carbide bit and laying under the grinding stone isn't much better, but I'll do what I gotta. If you have any tips on what shape of stone or carbide bit worked best for this please share. I've got a ball shaped and a pointed/round tip carbide bit. Only 16 total spot welds to do this unpleasant way. I appreciate any tips.

 

Depending on your year and model of the car your working on I can tell you this. I had to replace all the floor and trunk braces and install new floor and trunk pans on the 64 F-85 and I remember that the body has to come off to remove and replace one of those floor braces. I used a bunch of spot weld remover bits ( cheap ones ) from Harbor Freight and an electric drill.

 

Hey therobski. I've got a thread under the major builds, and think you've posted a note or 2 there. This is a 67 Cutlass (Supreme Convertible). Body is off the frame and the floors are mostly out. From your pictures the floor braces look pretty similar to mine. I've been using a Blair Spot weld cutter (11096 cutter set) along with the cutting lubrication stick they sell, and for the spot welds I can get flat/square on inside the car it's done quite well. My question is regarding the ones where the floor braces are attached to the inner rocker, and with the regular drills I have I can't get flat/square with a drill bit not fully extended. I don't see how a drill bit or spot weld cutter can cut if the drill isn't flat/square/perpendicular, and for me the shape of the brace prevents that. How did you manage to drill those out? One of those right angle drills?

 

Chisel? Air hammer and chisel tool.

Or, cut away the other stuff and then attack what's left?

 

i do have an air hammer (Harbor Freight air hammer chisel set). I think I should grind one side flat and perhaps "sharpen" the end so it does better for this particular purpose. I have heard other advice to not use an air hammer because one can mess up the metal they want to preserve. In this case I'll go slow and careful. Perhaps a dual approach of using the die grinder to thin the spot welds and then the air hammer. Simmering, simmering....

 

All good approaches. You are in a repair process, so any damage done to the other metal will simply be repaired along the way. Minimize of course, but it happens in order to get stuff done.

 

The braces are the same! Yes-I used an air chisel and did a little more than it needed but all was repaired-a learning experience indeed. The body off is great. Is it on a rotisserie? If so another tip if the underside including the wheel wells have rust or undercoating that you are not replacing go out and get a "needle scalier". Works great, chips away the rust and undercoating. If you do have old undercoating that needs to be removed, make sure the part you needle scale is cool not out in the sun or it does not chip away easily

 

cut the brace apart, then you can either drill or grind the spotweld. air chisel will make a mess of the rocker IMO

 

I ground down the spot welds with carbide bits and then went after things with the air chisel. It worked well, but the rocker panel underneath is rusted where the brace was attached so it'll get some patch work. Here's some pics in case someone else wants to see the details of one way to tackle this.

 

Therobski - Unfortunately I don't have a rotisserie. I do have a Harbor Freight version of the Dremel Multi-Max and that's been pretty good for knocking off undercoating in wheel wells. I'll keep the needle scaler in mind, but my compressor is only 10 gallons and waiting for the compressor to catch up gets annoying

 

seanm12 looks good. We learn to work with what we got and the end result is its gets done. In the pictures the spot welds were done at the body shop, not me. Seam sealer was my best friend on this part of the project!

 

I found a masons chisel works very well. They are wide and very thin. I have had mine over 30 years and busted through many spot welds. Find them at home depot etc.

 

A right angle drill wouldn't have worked? I know I am late to the party but there are small right angle drills that might have been able to use your cutter just thinking out loud