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Username Post: Lap floor pan patch over cross member or...        (Topic#370303)
383 Malibu 
Posts: 21

Reg: 10-08-08
12-08-22 06:16 PM - Post#2851072    

First time doing metal replacement. Replacing part of driver's side floor pan on a 1981 Camaro. Rust does not go any farther back than the front of the cross member under the front edge of the seat. In trying to keep as much factory metal as possible, would it be advised to cut original floor pan on top of cross member right to left, then lap replacement over original floor on top of cross member? Lap joint would not be visible from under the car.

Or, should I go back about another 8" and butt weld? A lot of extra work if I did it this way.


383 Malibu 
Posts: 21

Reg: 10-08-08
12-10-22 05:13 AM - Post#2851123    
    In response to 383 Malibu


"6th Year" Silver Supporting Member
Posts: 843
Loc: Ohio
Reg: 12-17-06
12-10-22 05:27 AM - Post#2851124    
    In response to 383 Malibu

I my opinion I would overlap and either drill out holes for spot weld, then seam seal along the edges or run a welded bead along overlap edge. Im not familiar with your car but my impala has lots of overlapping on the floor pan areas from the factory and then pinch or spot welded together


65' Impala SS, 65' Belair, 89' Silverado Z71, 95' Silverado Z71, 12' Silverado, 15' Silverado LTZ, 16' Tahoe LTZ

Edited by 995jim on 12-10-22 05:27 AM. Reason for edit: No reason given.

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Loc: Baltimore, MD
Reg: 11-27-04
12-10-22 09:18 AM - Post#2851129    
    In response to 995jim

You could do it either way. But honestly I would do the lap joint or a butt weld joint off of the crossmember so the you and get corrosion protection and seam sealer on the welds and joint. If you do it over the crossmember the seam will be inaccessible.

Friends don’t let friends drive Fords.

1999 Silverado Z71 4X4 extra-cab short bed
1983 Malibu Fauxmad - tubbed
1978 El Camino Kustomized
1972 Monte Carlo
1957 210 handyman wagon
1957 Nomad sport wagon
1957 Cameo Carrier

383 Malibu 
Posts: 21

Reg: 10-08-08
12-12-22 04:56 AM - Post#2851185    
    In response to wagonman100

Good points. Thank you guys!

Member #1510 Senior Member
Posts: 4084
Loc: Chesapeake, VA, U.S.A.
Reg: 04-14-01
01-11-23 06:11 AM - Post#2853322    
    In response to 383 Malibu

A lap joint with seam sealer will suffice. I did it on a '97 Wrangler a few years ago that held up just fine. The new owner is happy.

Like others have said, it is how the factory does it in a lot of places on a vehicle.

Just pay close attention to any areas where a floor pan connects to bracing via welds. It's important to reestablish those connections for structural rigidity.

Good luck!

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