Repairing Floor Pans

zerbydd · 11-23-08, 08:42 PM

Alright well i was thinking of something else for the car yesterday. When i was under the car doing the tranny, i noticed some bad spots in the floor pan. Holes going right through. rusted. Not really a whole lot, but pretty much spread out throughout the floor pan. Should I just replace the whole floor pan or just pieces? if i were to do it, this would probably be the biggest project that i would do yet. I found the floor pans at NPD, paddock, and year one. All reasonable prices. is there anywhere else that may have floor pans? How hard would it be to do the floor pans myself? What would i need? Am i going to need a auto rotiseree?

Chuck · 11-24-08, 03:20 AM

If they are not that bad I'd just patch the holes. If it's like swiss cheese then replace the whole thing.

Chuck · 11-24-08, 03:22 AM

Check out Mikeb's floor repair job http://hardcorepontiacs.com/forum/37...forum-lol.html (I may bee asking a few questions here in this forum LOL)

zerbydd · 11-24-08, 04:14 PM

No it's not swiss cheese. Just a couple spots throughout the bottom. So pretty much any welder i have is good to use?

Sirrotica · 11-24-08, 05:00 PM

If they're just small holes fiberglass patches are easier than welding. but if your gonna weld I have used either gas welding or mig with shielding gas. Flux core doesn't work well on thin metal. Make sure you know where your fuel lines are when you do this.

zerbydd · 11-24-08, 05:19 PM

All i have is a mig welder. Flux wire i believe. it is my buddy's. Did a few things with the welder. I am not too bad at it. But that's all we have. I believe it's the flux wire. It comes out the tip when you press the button and you touch it to the metal and it starts to weld.

Sirrotica · 11-24-08, 05:43 PM

If there's no tank involved then it's flux core. You can try it but I never had any luck welding thin rusty metal with it.

zerbydd · 11-24-08, 05:51 PM

Well, i guess i'll see. It won't be for a while that i even start it. Just wanted to get some ideas.

Mr. HARDCORE · 11-24-08, 11:22 PM

Flux core wire is just fine if you get the settings right on your welder. I've used it for many years. That metal isn't that thin anyway.

freebird67 · 11-25-08, 05:26 AM

Fluxcore is fine if your welder has a variable setting. Mine unfortunatley only has high and low which is a pain. You really have to listen to the burn and watch the puddle and stop it before it burns through. Stop to soon and all you do is add a bubble of slag.

mikeb · 11-25-08, 08:07 AM

I used flux core wire for my floorpan welds. The welds are ugly and I had a lot of trouble with burning thru the metal, but it worked well enough. The more I welded with it the better I got. I found that the key is to get the replacement piece to fit as tightly as possible. Gaps are a bitch to fill in, and you usually wind up creating a hole instead of filling in the gap.

zerbydd · 11-25-08, 01:36 PM

yeah the one i have has the knob setting on it to adjust the heat

Mr. HARDCORE · 11-25-08, 01:43 PM

You need to adjust the speed as well. The sound is similar to frying bacon. lol!

zerbydd · 11-25-08, 01:55 PM

i don't think it has a speed setting

zerbydd · 11-25-08, 05:05 PM

Well i did look under the car today and there really wasn't as many spots as i thought. When i was under hooking the tranny up, i took a gander. I will just be patching. Shouldn't be that expensive to get some sheet metal and cut and weld. I do have a question. can i just cut around the hole and just through a piece right one top of it? or does it have to be exact cut to fit inside the hole?

mikeb · 11-26-08, 07:24 AM

Quote:

Originally Posted by zerbydd

Well i did look under the car today and there really wasn't as many spots as i thought. When i was under hooking the tranny up, i took a gander. I will just be patching. Shouldn't be that expensive to get some sheet metal and cut and weld. I do have a question. can i just cut around the hole and just through a piece right one top of it? or does it have to be exact cut to fit inside the hole?

Either way will work although if you overlap it you create the potential for future rust in the overlap.

poncho1961 · 11-26-08, 07:58 AM

The exact fit method is better as it doesn't leave a flap where moisture can hide. But in a pinch, you could do the overlap, welded form both sides or coated with a good sealer such as POR products. One other thing to try on the thinner sheet metal when welding small areas. Take a piece of copper pipe and hammer it flat. Support the flattened copper snuggly up against the patch from under neath. Use a bottle jack or something to wedge it snug against the seam. Weld from the top. You will have to move the copper around as you weld. It acts as a heat sink and pulls out some of the heat that will cause burn through. If you do burn through, don't worry, the weld doesnt stick well to the copper.