The Stovebolt Site Forums The Shop Area Paint and Body Shop flange weld or butt weld?

When I cut out my toeboard/floor and install the new sections, should I butt weld the toeboard area or flange weld it? It won't be a straight line going across because after reading what other people mentioned, "fit the piece to the truck, not the truck to the piece". This will be my first attempt at butt welding sheetmetal this thin. This is the only area that gives me the greatest concern. Any ideas, suggestions, comments...yelling!

Thanx

The floor/toeboard is one area I wouldn't mind a flange for welding for the strength, particularly if it could be welded from both sides. For butt welding, very short duration on the weld will help prevent melting holes in the metal. Less than a second. Just experiment first with scrap metal.

two thoughts (1) how good are you at welding? lap or flange joints are more forgiving.(2)if you want to butt weld get some copper pipe from home depot or something like that and hammer it flat.you can use this to "back" the weld to reduce burn thru. the weld puddle will not stick to the copper and it acts as a heat sink. practice on some scrap and see how comfortable you feel.also go slow 1/4 inch beads about 1"-1 1/2" apart to prevent or reduce warping.others will chip in i'm sure because i know i've forgot something good luck tom

on my 1st truck I started butt welding, but it seemed more trouble thanit is worth on floor patches-then I started lap welding & life was much easier. much easier to weld & less warpage. yes, a lap weld can rust between the laps, but I won't be around by the time it causes trouble. If you look around, the whole truck is comprised of lap welds. brian

mummdogg,

I have only replaced one panel on my truck, and it fit perfect. I have seen the comments about fitting the piece to the truck and am not sure I follow that approach.

When you do your floorboard/toe board, why can't you use your abrasive wheel to cut out sections following a nice straight line. It seems it would be easier to fit the new piece in, and would look much nicer.

You don't want to randomly chop stuff out of the way. Clean the material that will be removed, and make nice lines with a sharpie. Use a nibbler, or a abrasive wheel to dissect the piece following the lines.

I have seen your truck and know you have quite a bit of work ahead of you. Done properly, it will be fun and rewarding.

Did you ever decide on a little welder for this project?

Stuart

Butt or lap weld, probably the most debated issue on the autobody forums across the net.

My take is this, there isn't one single butt weld on your truck from the factory, not one single one. There is however lap and pinch welds, EVERY single panel is attached with a lap or pinch weld. This whole floor you are talking about is held in with lap and pinch welds. How on earth could one more be a bad thing?

If you put a lap weld that "looks like it belongs" it will be as good a repair as you can get in my not so humble opinion.

That floor for instance, if you cut the old one off about an inch from the original pinch weld and lay your new piece right up over that strip of the old floor up to the seam from the original pinch weld and plug weld it to the strip, THAT is going to "look like it belongs". If a guy looked at it who didn't know these trucks inside and out he wouldn't even know you did a thing!


No need to fully weld them either, again, there are about four weld beads (short ones) on your whole truck. The rest of the truck is held together with spot welds, thousands of spot welds. A plug weld did with a mig is even better. Soooooo, what in the world is bad about a few more of these type welds?

Make it easy on yourself and do as good a job as they did when they built the darn thing fifty years ago, lap weld it with plug welds.

I replace damaged sheet metal on a weekly basis and I have found the best way to cut a striaght line is to lay a piece of masking tape down and cut along it. Use a 1/32" cut off wheel in a die grinder and run it back and forth a few times thinning the metal alittle THEN start cutting thru.

Brian

Thanks for the replies. I've done my fair share of welding at a prior job, mostly stick welding and MIG on thicker sheet metal, so this thinner welding is somewhat new to me. When I cut out the old toeboard, the cuts will be straight, not curved. It won't be straight across from drivers side to passenger side in on continuous cut. Alot of the cuts will be on 90's and 45's. As far as using the copper for backing. After switching from CO2 to 75/25 (argon/CO2)I tried it on some plug welding this weekend and it worked great. Was able to create a nice weld pool. Thanks for the advice on that one TPYLE. I'll be getting the new sheet metal this week and hopefully will start working with it this coming weekend, depending how I feel after my 20 year class reunion! I'll post some pictures in my webshots to show the progress when it happens.

If you are going to overlap and then weld along the edges, or overlap and plug weld, I suggest a 'weld through etching primer' so that the insides of the overlapped edges have a better chance of not rusting.

I also may be trying to replace a floor pan. what do you mean by plug welding.

A plug weld is when a hole in the top piece is filled with weld material thereby attaching the top piece to the bottom or supporting piece.

Remove your old floor pan, leaving enough original material around the edges to support the new floor pan. Drill holes every few inches around the new floor pan so that these holes will be over the supporting lip of the old floor. Weld through the hole in the new pan to the supporting material. This is a plug weld. The size of hole depends on the thickness of the new material. Use some scrap and practice. I would start with a 1/4 inch hole about every 2 inches and see how that works for your situation.

OK thanks it will be about a mouth before I get to my. can I use stick welder to do this or should I get a meg welder

You can use stick, but mig is easier to control. If you have access to a mig machine, use it.

I can't imagine using a stick welder to plug weld sheetmetal. I mean, I have only used one years ago on a frame but a stick welder and a Mig are MILES apart.

Beg barrow or steal a MIG. There are places that rent them around here. You can buy a nice set up for about $600.00.

If you want to read a "Basics of Basics" to MIG welding (including a explanation of the "plug weld") go to http://www.camaros.net/forums/showthread.php?t=13135 print it out and read it over and over.

Brian

Brian,

I should have qualified my statement about using stick to weld sheet metal. If you are a skilled sheet metal welder it would be no problem. Then again, you would probably be 60 plus years old. At one time all sheet metal was welded with something other than MIG. Gas torch, stick, or TIG. Like you said Brian, stick would be my last resort to weld sheet metal with.

Sorry if I mislead anyone. If you are going to do automotive repair and fabrication, get a good MIG machine. Get a 220 volt machine that will get you in the 200 amp range, that is if you are going to do any frame or bracket fabrication. A 110 volt machine will do well for sheet metal, but you will be disapointed trying to do frame work.

On one of the hot rod shows they showed some lapwelded floor repairs which were cleaned up a bit with a grinder, then primered with a rattle can, and then spread with undercoat. The body guy said the repair equals original construction.

MORE than a year ago when I started into restoring my '42 I bought a Henrob oxy set up. I blew holes in everything for a while, varicose weld beads, then left it sitting in the shed while I contemplated buying a MIG or a TIG. I had enough other stuff to keep me busy.
Have commenced sandblasting the cab/frame after building a blaster and blast cabinet and while blasting today began exposing small cracks which had been plastered over with Bondo some years ago by a previos owner.. Went to the Henrob website and found a new video tutorial and paid it a lot of attention.
I had already completed a rust cut out job at the bottom rear of the cab, with flanges and plug welds, but after the tutorial I was able to confidently wade in with a 1/16 copper coated metal rod filler and lay neat, clean welds into all of the cracks, no warping, good penetration, no spatter and a thorough job. I'm going to attempt to butt weld the best parts of two front fenders together come next Tuesday, something I was dreading and putting off. I'm sure it will go OK now.
Just lucky I did my homework I guess.

Henrobs are VERY hot torches. You have to use the tiny tip to do something along those lines and then really be careful about the heat.

However...very hot can be very good.

I got the kickpanel mounted speaker thingys at the last swap meet and found that the driver's side was going to foul the park brake. I went in with my henrob and was able to heat just a band across the pedal and bend it in quick like without burning up everything else. Viola! It now is cranked over about 20 degrees and will not foul the speaker.

I do have an automatic tranny so no clutch pedal to mess with.

I also used it to adjust the shift rod in my 59 1 ton to be at optimum angle for ease of use with my GMC van seats.