Welding joints

[jremig]

Hi, I'm Joe and I'm new here to the site. What is an acceptible weld joint when replacing panels in an AD truck? Are butt jounts preffered or will lap joints work also? I'm getting ready to replace the floor pans in my 52. Here is what I have going on right now http://s1166.photobucket.com/albums/q611/joeyremig/

Joe

[Kim57]

Welcome
IMHO but joints are the best. Lap joints can let moisture in and you will have a rust problem down the road.
Kim

[jremig]

Also I was thinking if I should keep the repair size to a minimum? Or should I just go ahead and cut out the whole patch for the floor?

[Kim57]

Make it large enough to get rid of all the rust damage. I like to keep as much original metal as possible.
Kim

[mr48chev]

Lap joints can pick up moisture but should work on floors ok. You would have to make a step flange in one piece or the other to get things as level as you could though.

Years ago when he was going to Perry Tech my first born made me a flanging tool out of a pair of vise grips that puts a step/flange in sheet metal that is just right to lay a matching piece over the step and have everything level. One of the rod magazines in 1988 or early 1989 showed it and he made one.

On an outside body panel the overlapping joint would most likely show though the paint after a while.

[mknittle]

Butt weld body panels! It is almost impossible to work a flanged seam after it is welded!!
But like mr48 said it works on floors, it actually adds a stiffener along the flange. I would use seam sealer At least on the underside.

http://search.eastwood.com/search?w=flange%20tool

[63 & 64 Bowties]

I guess I'm in the minority, but I like lap just because the cuts don't have to be exact and you've got wiggle room for perfect alignment.

[Kabwe]

If you really want a nice job that you can metal finish with very little filler butt welding is the only way to go. I do agree with the guys that with floors it does not matter but for me I only lap joint were there was factory lap joints. If at all possible I butt weld everything.

[55metalmonkey]

Originally Posted by Kabwe

If you really want a nice job that you can metal finish with very little filler butt welding is the only way to go. I do agree with the guys that with floors it does not matter but for me I only lap joint were there was factory lap joints. If at all possible I butt weld everything.

ditto,
if you take your time and match up the edges perfectly, weld it with ssmall spot tacks all the way around and grind it flush you should need next to no filler especialy if you can hammer and dolly any low/ high spots to flush. It takes a little more time to fit your peice this way but in the long run it will save you some grief from not having to fill and sand as much.

this is how I did this fender, http://67-72chevytrucks.com/vboard/s...d.php?t=486137 (25th post down)

[Rude Dude]

If using lap weld, welding supply places carry weld thru primer in spray can

[jremig]

Thanks for all of the replies and advice. Will post more pictures when I get the pans cut and welded back in.

Joe