Weld seams

Discussions about general body work and modifications
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boone
Posts: 16
Joined: Sun Apr 29, 2018 5:09 pm

Weld seams

Post by boone »

A question for you body guys-I have done a little body work myself and before I look at putting floorpans in my 65 I was wondering this-so when you cut the rotted/old floorpan out-I have seen where there is a little flange left around the outside-then the floorpan is basically set on top of this flange,set down tight then spot welded in from the top-then you go underneath the car and spot weld the bottom side of the flange to the floorpan also. Now the other method I have seen is where you cut the old floor out and then cut the new piece to fit the hole exactly and butt weld the new floor pan to the good floor with no flange where the two pieces stack on top of eachother my question is which method is better?-it seems to me that the flange idea would be quicker and easier but is there any chance of the floor rusting from the inside out where the 2 pieces overlap eachother? or does it hold up better than I think it does as long as you maybe put a thin bead of seam sealer or maybe a good primer or something in between the flanges before you weld it?-the idea of trying to cut the new floor to fit exactly into the spot you cut out seems maddening to me but I have tried to think of the pros and cons of both methods- if the flange idea is the way to go how much of flange do you allow?-is there any trick of the trade length that the 2 should overlap eachother at this flange? what do you guys think?

and another question-I have seen a lot of you guys making your own floorpans/subframe connectors-I do turn wrenches for a living but I have limited body tools-does it save any time/money making your own pans and connectors or is it better off to buy these parts? I guess maybe it would be a matter of what each person thinks his time is worth?

Lou's Comet
Posts: 1539
Joined: Sat Nov 26, 2011 8:56 pm
Location: Jeannette, Pa.

Re: Weld seams

Post by Lou's Comet »

First question....depends on who you ask. I myself the majority of the time use the flange. I have butt welded panels before but prefer welding them with a flange.

After you get your new panel trimmed, ready, etc, lay it down on the old and get it to fit as good as possible. Clamp it in place, drill a couple 1/8" holes about a 1/4" in from the edge of the new panel down thru both panels. Use a couple screws or clecos to hold panel in place. Then with a marker trace around the new panel on the old floor to mark it.
Remove the new panel. I then run 1/2" masking tape around the inside edge of the marker line. Marker line is visible .

This will give you about 5/8" flange once you cut around the inside of the tape. Then use a flange tool(there cheap) to step th metal where your new panel will fit. After flanging it the new panel should lay in there pretty much flush. Line up the holes to position the panel, then weld in. I will drill some holes a 1/4" in from th edge of the new panel to plug/spot weld it in place. Then weld the perimeter of the panel. I don't usually weld the underneath, unless on rotisserie. Sucks welding upside down!

Keeping it from rusting is sealing it good. If you seal both sides and paint. Really can't rust unless you have failure of the sealer or paint. When I did the floors and frame connectors on my Comet I used panel adhesive to seal all my seams, inside and out. Then sanded the adhesive smooth, epoxy primed and painted

Some things to remember clean metal, clean metal, clean metal! The cleaner the metal the better the welding. Rusty dirty metal not so much.

As far as buying or making your own. I made my own. Had less than $100 in metal for all my floors and frame connectors. A lot cheaper but does take more time. Did buy the repair panels to start with and even put one in. But didn't like how they fit and they were not large enough. To cover all the damages areas, most but not all. So I had to make some filler pieces. It was starting to look patch work so I just made my own. Depends on how much you enjoy making/dabbing stuff, I really enjoyed doing mine and a lot happier with how it all fits

Lou

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