I have cut out a section of my passenger floor pan to be replaced and have a replacement pan to cut the replacement section from. My question is, can I go ahead and cut the new "patch" 1" +/- larger than the hole and weld it in with a lap or try to create a perfect fit with no lap as I have read in some topics. What have you guys done ? Any do's and dont's are welcome.

Thanx, and this will be the only posting of this question....... graemlins/hurray.gif

-John

A lap joint in that location, in my opinion, is an open invitation to rust. Even if you plan to garage the car and never drive it in the rain, there is always the chance that you'll get caught in a sudden downpour. When water seeps into that joint, it'll just settle there and it might take days or weeks for it to dry. I recommend a butt joint using a piece of brass on the backside to keep from burning a hole in the metal during welding. You could lap weld it and seal the joint, but the repair would be obvious. If you are building a show car and you plan to put mirrors on the ground to show off the underside of the car like I've seen so many people do at Dallas Autorama and Fort Worth Rod and Custom shows, then you don't want to do a lap joint. It all comes down to the finished appearance you're looking for.

I am in the middle of a similar repair to my Elcamino floorpan. The car spent its life in AZ and still managed to soak up enough water to perf a few low areas of the pan. I figured the same as Randy in that a welded lap joint would likely attract & hold moisture. Besides, welding would wreck my nice POR-15 underbody paint.

I began a repair with fibrglass mesh but didn't like how that was going so I got a replacement pan section.

What I've decided to do is cut the floorpan back to within a half inch or so of the rocker, back wall, and top of the tunnel, and trim up to the floor support brace, and then trim & glue the panel with a lap joint & Fusor adhesive from http://www.autobodystore.com.

The seams will be less noticable from underneath, and the adhesive should seal out moisture.

I should add that the area I'm repairing is the back half of the driver's side, not the complete floorpan.

Great advice !! I am not building a show car so I would rather go with the lap for ease of installation, although the butt joint is best of course. I will be applying some kind of sealant at the lap to prevent moisture penetration and I also have the pan coated with POR15 so I think I can get away with the lap joint. Thanks again :cool: