TECH Request: Sheet Metal Welding Question

[NealinCA]

I am in the process of shortening a 33-34 bed to fit my 32 p/u project.

I have taken a 5" slice out of the bed, fit it up real close, and now have a butt joint about 18" long to weld up.

I use Oxy/Acetylene and have made 1/2"-3/4" welds spaced 3-4" apart to get the pieces held in place. I hammer and dollied each short weld immediately to make sure everything was good and flat.

Now I am to the point where I need to weld it up tight.

What is the best technique? I am thinking more short welds like I have started doing, but should I be quenching with a wet rag after I hammer them flat?

I usually just learn by doing, and have done OK on small repairs, but I thought I would ask before I made a warped mess out of these bed sides.

I am hoping for a nice smooth seem that doesn't need much more than some primer and block sanding.

Any suggestions would be appreciated.

Thanks,

Neal

[DrJ]

By the time you finish hammer-welding it will be cool enough that the only effect water will do is rust it and harden the metal so that hurther hammer 'adjusting" will be difficult.
I wouldn't quench it.
I only quench if I want to shrink an area, a lot.
Been using the cold compressed air method lately instead.

[TV]

Nealin, the best way to do this is very short welds as you've been doing. keep skipping around and hammering as you go. Don't quench wit a wet rag, this will tend to make it hard. But keep feeling it with your hand and try to keep the whole panel as cool as you can. This shouldn't be much of a problem as you have two sides to work on and you can jump back and forth.--TV http://www.jalopyjournal.com/ubbthreads/images/graemlins/cool.gif

[Tinbender]

Yep, what the Doc said. Sounds like your doing fine so far. I never cool with water, even when heat shrinking. I use compressed air, as needed.

[30roadster]

i use a 00 victor tip and some .045 welding rod. You can use straightened pieces of mig wire if you want. I'd keep splitting the difference between your spot welds till you are about 1/8 of an inch apart - then zip it up slowly taking lots of time to let it cool and moving around alot.
dolly between each pass of spot welds. don't be in a hurry..... if you see spot welds in your sleep you're right on pace http://www.jalopyjournal.com/ubbthreads/images/graemlins/smile.gif

[kustombuilder]

i agree with what everyone else said...

[NealinCA]

Thanks for the replies. I have had people tell me to quench, but it just didn't sound right.

I will proceed with the short hammer-welds and report back. Hopfully I can get it welded up this weekend.

Thanks again,

Neal

[Paul]

[ QUOTE ]
i agree with what everyone else said...

[/ QUOTE ]

yup,

'specialy the "don't be in a hurry" part

[alchemy]

Works even better if you have a freind do the hammering while its still hottest. It cools considerably while you are setting down the torch and picking up that hammer and dolly.

[choprods]

I envy your steadfastness with the torch..... http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gifbut don't be Amish- do the rest with the Mig.

[Tman]

You can quench, but by the time you do it, you get a small "hiss" not the Old Faithfull "whoosh"! When you do it this way you are just keeping the metal warm, you still need to skip around. I think most folks shy away from quenching cause they heat tooo much and hammer tooo little then quench while it is still WAY to hot! When you end a hammerweld session, the panel will be warm to the touch. You dolly prob will get to hot to handle a couple times if you are working hard!

[kustombuilder]

F*&K the MIG! real men use torches http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif. it really is a better way to do it. MIG welds are HARD and more dificult to weld plus it is nearly impossible to work the seam with a hammer and dolly without cracking the weld.
there is no reason whatsoever to quench it either, just take your time, thats the only way to do it right and have it come out the way you want it to.