Technical Butt weld or overlap when welding in floorpans?

What ever happened to the traditional way of using sheet metal screws, pop rivets, and roofing tar? Geeze, got to make everything complicated....

I lap welded my floor patches. Don't care what it looks like underneath, you can't see under there unless it's on a lift anyway. Peel and seal and carpet covers the top. It'll be here when I'm gone, the next guy can do what he wants with it.

 

HAMB cars are a least 55 years old and most factory welds are seam.

 

Forgot about this thread! Well, I butt welded everything. Primed and sealed it and I'm done. Definitely improved my welding skills and am very pleased with the outcome!

 

Doing it properly is less complicated and simple.

 

Looks great

 

Ever look how the pieces to 20s and 30s sedan rear sheetmetal is welded?

 

That finished product looks really good. You made the right choice there.

 

I spot in with MEG - then butt weld with a Henrob gas torch. Takes much more time - but better results and can hammer weld and metal finish and the welds will not crack.

 

I've done both, depends on what type of car (only car/driver or project), how much time you have and how much patience you have . I overlapped patch panels on the floor and plug welded them on a daily (only car) only removing the carpet (welding blanket the rest), weld through primer, seam sealer inside and wet roof patch on the underside (no grinding needed). That was '95/'96 and it's still solid without any rust.....still looks ok as I used undercoating after the paint.

 

I butt weld and use, where practicable, factory seams that I plug weld. More work but nicer. I don't use a joggler and overlap joins unless it was OEM.

 

When I worked for the Park service in Pa. they had vehicle inspection and part of it was checking for rust. Holes in the floors or trunk was reason for failure because of fumes in the car.
A fellow worker asked me to put a trunk floor in his old Buick Skylark. He said do it as quickly and cheaply as possible as it was his winter car. So chicken wire pop riveted to the edges of the trunk because there was nothing in the middle . Laid down a layer of aluminum foil the good heavy duty stuff. Then a layer of fiberglass mat and poured resin over that. The foil was to keep the resin from just running all over the top of the gas tank and on the ground .
It passed inspection and the state was happy and he didn't have to scrap a good running car for a rusted out trunk floor. Not a concours repair ,but it worked.
They had really stupid rules. You couldn't put tape over a rust hole, but is you painted the tape it would pass.
When I was a kid growing up in Michigan they used salt about 5 months out of the year. My dad worked for the county highway dept. and he brought home old road signs and they worked great for floor pan patches. Of course back then tri 5 Chevys were just old cars and you could buy one for 50 bucks.

 

I'm getting too damn old to waste time trying to make the floor under the carpet and matting look too pretty.
Lap welds are easier, faster, and will outlast me. With proper prep , they'll even look pretty damn good underneath that heavy coat of undercoating.
Fix it. Drive it. Enjoy it.

 

im with you . 2o yrs is all ANYTHING has to last!!sad but true . your floors do look great++++++I did the sheet metal screws on my 50 wayfarer 30 yrs ago , long before I had a mig welder or torches . did have a 110v buzz box I think ? anyway still working fine and no one has yet to lift my carpet and comment. might not be pretty if they ever do

 

The real answer is perfecting hydrogen fuel cells. Mining lithium for EV batteries causes lots of problems and damage. Also, what is going to happen with all the used EV batteries? That # will be in the hundreds of millions. I know EV's can be fast and all that but, cool? There has not been a cool car made in over 50 years. Tesla's are fugly as it gets!!
As for the original topic, pretty much every car produced is lap/spot welded together. If the makers employed welders to butt weld panels together and people to finish the welds, the cost of a new vehicle would be more than double.

 

Quite a few new cars are glued together aren't they? If there over lapped and glued that would certainly help in the moisture intrusion wouldn't it? Could be something I'll look into in the future.

 

Yup, nobody gets out alive.