body work question..butt weld or overlap

All you body work guru's. What is the better way to weld in a patch panel butt weld or over lap... I have a 54 chevy with cut up quarters and i need to patch them. I do have another car with good quarters so i can take what i need from it. any help would be greatly appreciated. Thanks

 

Butt-weld. Always. If you overlap, you create a pocket for dirt/corrosion to start.

 

always butt weld patch panels..

 

Butt-weld...

 

overlap welds are much easier. just like spreading the mud a little thick is much easier than doing some more metal work.

the first patch job I did I butt welded. never considered doing it any other way.

 

I butt weld all patch panels unless they are made to be overlapped originally.

Hard to tell from the pics as to whats damaged but Id suggest cutting in the panel behind the trim and fix as much metal in one shot. Pretty much just figure out what you need and cut it off the donor lay it on to the fixer and trace it out and cut it or tack the two panels together so they are tightly sitting over each other and cut through both at the same time. If you do it right youll end up with a perfectly matched cut with a small gap that it usually just the right thickness to mig.

Its not at all hard just go slow and spend time prepping the metal before you start welding. grind off everything on the front and back of each panel about 4 inches away from the seam. Spend a good deal of time measuring on the donor to get the wheel arches in the correct spots and then spend some time getting it to match on the fixer.

 

All the original panels on every car or truck ever made are overlaped at some place , edges , braces etc , think about it , you only need to but weld for original fit

 

Thanks for info guys, the panel is missing a bout two inches on the rear of the quarter and the wheel arch is rotted out. Cal thats what im planning to do. But i had a guy tell me to flange the panel and overlap it...but looks like the right way is to cut under the trim line and butt weld....
Thanks again

 

I vote the butt...


weld that is...

 

butt weld patches, and weld solid, or they will show up later

true, factory panels may be overlaped, but not in the middle of a panel



skull

 

Butt weld patch panels. It you are putting in a floor section, you could over lap that piece.

 

I didn't even read your post, but the answer is butt-weld.

 

another vote for butt. overlap is for rivets.

 

I cant help myself...always buttweld as mentioned unless it is some kind of factory lap that I have to repair, and I always seal up,cover, paint etc the back side of the weld seams...and dont leave any pinholes they will come back to bite you in the ass!

 

Butt-weld.

 

Butt weld. Give yourself a little gap for the filler rod, maybe 1/32 of an inch. Go slowly, and don't burn a hole through your metal. It's a delicate balance of on-off welding, unless you have a tig welder and can control the puddle better. It's also nice to have an air source close by to keep the panel cool as you go. So, weld about 1/2-1 inch. Then cool it with air. Then weld the next 1/2-1 inch section. Cool with air. You'll get the hang of it.

 

The cool with air thing.
Every metal site I have looked at, says do not cool with air or water..
Hard to know what to do as everyone has a different method and different ideas..

 

i saw on an episode of monster garage once that said a weld is not fully cured and ready for the grinder for at least 20 minutes. i also heard that force cooling a weld can make it brittle. just going off what i've heard, but it makes sense to me.

 

A mig weld is brittle as soon as its made.... Force cooling it with air only makes it worse. My way is to make a good full penetrating tack and wait a few. Make another opposite the first then split the difference.

Its alot like upholstery, staple the middles then split the difference all around then split that difference ect. It keeps the wrinkles out and thats how I do it.

 

I'm a butt-man myself.

 

Thanks for all the good info guys...I was going to go to santa maria but really want to get things going on the car so thats this weekends project. Ill try and post some pics if i can. I was talking to a guy at a recent swap meet and his advice sounded good. he said keep the palm of the hand your not welding with on the metal and if it gets to hot for your hand move to the opposite area of the panel...

 

I would step the panel then weld. Makes a much stronger panel.

 

Your skill level should be taken into account when answering that question. If it's first class, the butt weld is better for metal replacement inside the boundaries of existing seams. If it's not, you may get better results using flanged panel edges and plug welding the overlap. Fit is way less critical, the welds are easier to make, and there's slightly less chance of warpage because the flange stiffens the edges. Your call.

Bob

 

Which is exactly what you don't want. Think about it... your replacing a once solid piece of sheet. By adding a strengthening rib in it, you're not allowing the panel to flex the small bit that it needs to. That will cause the bodywork and paint to crack if/when the panel is stressed. No good.

Not to mention the haven you've created for rust and rot.

 

This is not good information.

Where the panels overlap is a great place for it to start rusting out again.

This will also make it next to impossible to properly stretch the panels back into shape, resulting in a lot more filler than would be needed with a butt weld.

 

Butt , of course .

 

wait.... how would an overlap weld even work out? wouldn't there be a noticeably high spot where you weld? and if you grind down that high spot wouldnt the metal be very thin?
- I'm not trying to be sarcastic or a smart-ass if it comes off that way, I just don't understand....

 

again not trying to be sarcastic or a smart-ass I just wanna know so I can do this stuff right too!... if you grind and sand 4 inches on the back side how do you get it sealed so it wont rust? I assume your talking about if you have the body pieces off? thanks gang!

 

Ok, so I need to patch a few spots also. Butt weld I understand--have the clips to hold it together, and welding vice grips etc.. I also have a Lincoln 110 and a Hobart 220v welders. I do a fair amount of welding in a fence business.
My understanding is that you use the .23 wire to keep the heat down. I tried some spots on 18 gage with .35 and it burned a few holes. So the best way to go is quick hits with the smallest wire available for 18 gage--correct? I understand the spacing to keep down the heat to prevent warping. Just doing a little practice before I start on some patches.

 

another vote for but welding....take your time.......practice on some scrap metal to find a rhythm that works for you....stick welds half an inch to an inch long move dont do too many in one spot to avoid warping the panel....hammer as needed...grind....do the next batch of stiches...hammer....grind....repeat ......don't force cool