A few basic welding questions for floor pans

ray moore · Nov 15, 2005

I need go over the welds on the underneath of the chassis where someone had patched in replacement floor pans, the spotwelds are about 12 inches apart right now. The edges are very ragged where they were cut out. I have a MIG welder
My questions:

Should I tack/spot weld in spots along the perimeter and then go back and continue to fill in the gaps with spot welds until the entire length is welded with spot welds,no gaps, sort of connect the dots, or do I run a straight bead?

Should I grind down the welds after welding?

Should I apply a coating of seam sealer after? if so any good brand recommendations.

Thanks
Ray

clwilcox33 · Nov 15, 2005

Did they flange weld the patch in or did they butt weld it in?

ray moore · Nov 15, 2005

I not real familiar with the terms but I would consider it more of a lap weld, They just cut out the floor pans leaving the tunnel, and then dropped in the new floor sections over top. then went below and tack welded every 10 to 12 inches. I will try to get pictures and post.

thanks
ray

HwyStarJoe · Nov 15, 2005

Ray, without actually seeing the floors yet, one option you have may be to cut the replacement pans to fit where you could then butt weld them in. That is, if the way they cut the pans is way off and there's tons of overlap. You might be able to cut some of the edges of the pans back, closer to the floor and then do just as you described.... tack along the seams every few inches and keep welding them in until done.
If there are hardly any tack welds holding the pans in now, you might want to see what's under them by grinding the welds and removing the pans. Have a look at the sheetmetal that's under them..... maybe clean up the areas better, or treat the metal before re-welding them in.

I would then grind the walds smooth and treat the welds with a good primer and then paint.

ray moore · Nov 15, 2005

Here are a few pictures of what I have, I need to do everything I can to strengthen from underneath, Unfortunately the interior is completely restored with Fatmat sound deadner already melted down and all new carpet. I (like an idiot) did my interior first without scoping out the bottom of car. I got into this while replacing springs and started branching out to the rest of the underchassis.

HwyStarJoe · Nov 16, 2005

Ray, Ray, Ray..... you get 69 lashes with an old tire for that!!!

Now that I've seen the pics, you definitely want to pull those pans and install them properly. Well.... you can't, but that's what's needed.
Maybe you still can without totally ruining the FatMat. Just cut it with a razor blade where the pans meet the floor. Then patch it with more after the floor's repaired.

A few basic welding questions for floor pans

ray moore

clwilcox33

ray moore

HwyStarJoe

ray moore

HwyStarJoe

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