floor pan butt weld or overlap

[73chargers4404]

give me your opinion

[Troy]

Define "overlap". If you "flange" the edges then the thin metal of the floor pans will be a bit stronger. If you literally mean to overlap them then I say it's a bad idea. The guy who owned my car before me did just that and I had to rip them all back apart because water can wick up into the area between the metal and rust it from the inside out. Most floors have plenty of support behind them so I prefer to see them butt welded. The trunk floor center overlaps already but you can cut the center and butt weld it once installed. With the gas tank in and a trunk mat it's be hard to tell at all even if you leave it overlapping. The front floors have carpeting but can be seen from underneath. If you undercoat the bottom then most people will never know any way.

Troy

[Silver R/T]

you usually butt weld them, at least thats what we did in collision repair shop. You can also drill holes on overlapping piece and plug weld also to backer, on bottom side, to strengthen the weld

[73chargers4404]

overlap as in a flange with metal laid over.butt weld i mean weld with a gap between the old and new metal and melt it together

[Drop Top]

I prefer to butt weld them for originality's sake. If you choose to overlap them be sure to caulk them afterwords. You don't want moisture to get in between the overlapped area and have another rust problem latter down the line.

[Doc74]

Since there's absolutely no reason to overlap or flange a floorpan, another vote for butt weld.

[4402tuff4u]

I vote for butt weld. I had the same question when I installed the new rear seat floor pans because they were thin in my 68. I was scared as hell to do it but after reading a welding book and watching the video that came with my millermatic 210 and playing/testing on spare sheet metal, I tackled it. I placed the new pans inside on location. The whole interior was out. Marked the outlined of the new pan with a sharpie pen and removed the new pans. I then measured approx. 1/8" - 1/4" below the outline I had just inscribed and drew another line below that following the original outline. Makesure the lines are parallel. Then I got a die cutter grinder and cut the floor out. Cut on the line. Do one side at a time and makesure the Charger is relatively level so you don't put eccentric loads on the frame. Then place the new pan and tack it at the corners. Then start tacking and filling in between the corners. Once you got approx. tacks every 1", then go back and fully weld. Once you grind it off, it looks like you never had replaced the floor pans. I did it and my body guy was impressed! Piece of cake.