Tig welding door panel questions

Pinesdune

Pinesdune

Senior Member
Hello and Merry Christmas folks. Just going to start repair on a CCPU for my CAA truck. As I approached this project (and the stack of projects I am collecting as time goes on) I made the decision to get a tig welder for body work as the consensus is that a tig is better than a mig for this. I am practicing daily my welds and am approaching the point I feel confident to tackle the doors and other sheet metal repairs. Would you folks suggest butt welds or lap welds between the new and old metal. I have seen both done in videos (more modern vehicles) but wanted opinions from those who have done it. Also the entire bottom is rotten on my doors so I need to replace both the skin and the inner part of the door bottoms, which would you do first? Any other tips and tricks would be greatly appreciated. Thanks
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Ditto Phil.
I used what we called skin pins to hold the panels in the right place while I welded. They are often used in aircraft assembly and go in from one side and by turning a knurled knob, they tighten in a pre drilled hole. Another way is to use SMALL nuts and bolts to hold them and remove after, then fill the hole with weld but watch for distortion.
 
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Butt weld...carefully measure your replacement panels and get as tight a fit as you can. Minimize the gap. I use those little panel welding connectors Eastwood sells.
 
If you weld it put a flat pcs. of copper behind were your going to weld. This helps to not blow throu as esay. I don't know if it works with tig welding or not. But weld
 
If you have not purchased the TIG, a better alternative is oxy/acetylene welding however the learning curve can be difficult With that said, the learning curve on a TIG can be sharp too.
 
I repaired the doors on my 29 closed cab two years ago and had to cut about 6 inches of completely rusted out material off the bottom of each door. I bought inner and outer patch panels. The hard part is getting the contour of the door to fit the contour of the cab. I made cardboard templates of the door curve before I cut the bottom off, to help in getting it right. One door turned out good. the other not so much! Note to self: spend enough time to get it right! The door openings can change after the cab is fitted to the frame, and the wood top frame has a lot to do with the fit also. Good luck with your rebuild.
 
l. bacon said:
I repaired the doors on my 29 closed cab two years ago and had to cut about 6 inches of completely rusted out material off the bottom of each door. I bought inner and outer patch panels. The hard part is getting the contour of the door to fit the contour of the cab. I made cardboard templates of the door curve before I cut the bottom off, to help in getting it right. One door turned out good. the other not so much! Note to self: spend enough time to get it right! The door openings can change after the cab is fitted to the frame, and the wood top frame has a lot to do with the fit also. Good luck with your rebuild.
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I like the cardboard template idea, that's a great idea.

Thanks for all the other ideas as well folks. [emoji106][emoji106][emoji106]

I've done some oxy welding in the past, for the cost of gas I felt this was a more economical way to go in the long run and so far I'm not finding tig welding that hard , just have to find my groove. Keep any more tips and tricks coming, thanks again
 
BRENT in 10-uh-C said:
If you have not purchased the TIG, a better alternative is oxy/acetylene welding however the learning curve can be difficult With that said, the learning curve on a TIG can be sharp too.
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I have found very quickly that for welding sheet metal Oxygen/acetylene warps the sheet metal much more than TIG and MIG welding. The least expensive to weld with is MIG welding. The only thing that you are out in MIG welding is the CO2 gas and the wire. Acetylene gas is very expensive.
 
I should mention that I used the panel bonding glue as Kurt mentioned, on my doors. I crimped the new patch panel, and the original lays in the crimp part. The glue is two part epoxy and was put on the seam after I drilled holes about ever four inches. I then bolted it together with tiny bolts, and removed the bolts after the epoxy set up. It took very little bondo to finish it out. I initially didn't think epoxy was a good idea, but reading and talking to people that have used it I decided to try it. I'm happy with it.
 
SSsssteamer said:
I have found very quickly that for welding sheet metal Oxygen/acetylene warps the sheet metal much more than TIG and MIG welding. The least expensive to weld with is MIG welding. The only thing that you are out in MIG welding is the CO2 gas and the wire. Acetylene gas is very expensive.
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Again, i think most would agree that it is all about technique. Here is a video that has been around awhile that has a great overview. Even the comments are worth the read.

https://youtu.be/Rv5bKXJ3kEM
 
I have a old Century, MIG machine. With .028 wire, the point of heat and the time involved for each weld (Tack) is so small that the heat never accumulates. No heat- No distortion! To butt weld 19 Ga sheet you must make a series of tacks , close together and then join the tacks with very short beads. Space the parts with MIG wire. Too close in the beginning and you'll have distortion when you get done tacking. MIG wire is .028 and the gap will close quickly enough. Weld between tacks by "Backstepping". Backstepping is a technique whereby one actually welds backward as you progress forward. The heat accumulates in front of the weld. So rather than chase the heats as it gathers in front of your weld, you beat it by moving forward and welding a forward area. We used this technique whenever we were welding thinner material where the heat was likely to accumulate.
Terry
 
The biggest problem with MIG is that it is a brittle weld. Subject to cracks, breaking and splits. Blow thru on this old metal is also a problem but that is true of all methods. You have to get to solid metal; no "thick and thin" or it blows thru.
I learned to weld by hammer welding. Funny thing is that is all we had! I also use a little jewelers torch alot which works on 5/5 lbs for small pieces and trim.
My vote is TIG....just wish I were better at it!!!!
 
A great thread and timely. I have some work to do on a Model T I just got and was wondering what to do? I have an oxyacetylene set and I learned to weld that way long. I really like it and it is fun once you get the hang of it.

I actually worked as a welder in 1974 for a while. I haven't picked up a welder or a torch since then....
 
IMHO, all 3 of these methods can be done successfully if done properly.
I have always been amazed with ability on a OA torch, like Gene Winfield, with a hammer and wet rag. Just amazing.
If you try MIG, use a small wire, solid with gas CO2, not flux core. (.016 or .020 wire)
The new TIG machines can make even me golden with ramp heat control, and stitching controls. Getting the setting right takes time, but worth it.
My preference would be MIG, most economical and relatively easy.
As with any job, having the proper tools and fixtures makes it easy.

John
 
As to what Bill stated above, MIG is probably the worse option of the three. I realize that is not popular to point out when it goes against other recommendations, --and it is the method that is most often what is seen used on the 'reality' TV shows, but it is the carbon dioxide in the shielding gas that embrittles the metal and makes it tough to work afterwards. As John stated, using a MIG is by far the easiest to master, so I guess it all depends on the your goals and expectations.


Merry Canadian Christmas to you too, -and best wishes in whichever method you choose.
 
BRENT in 10-uh-C said:
As to what Bill stated above, MIG is probably the worse option of the three. I realize that is not popular to point out when it goes against other recommendations, --and it is the method that is most often what is seen used on the 'reality' TV shows, but it is the carbon dioxide in the shielding gas that embrittles the metal and makes it tough to work afterwards. As John stated, using a MIG is by far the easiest to master, so I guess it all depends on the your goals and expectations.


Merry Canadian Christmas to you too, -and best wishes in whichever method you choose.
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Hi Brent, in total I have 5 projects to work on, a '29 Whippet, this 28 pickup, a '47 ford pickup, a '49 Hudson and my wife's '68 beetle. I took a basic welding course as part of my community college education in "farm mechanics" and am fairly proficient in stick, oxy and mig. To start my bodywork education I have been picking away at the bug as my wife buys the patch panels (floor pans/heater channels, fender well patches). My personal experience so far is the mig works great for slapping things together but as it's a "wire feed welder" , it uses way more filler rod than I wanted in most light gauge situations which then leaves me to the grinder which can ruin/warp a flat panel faster than any heat made from my welds as it's just way to easy for me to keep grinding rather than to let the metal cool, I just get in a groove and before I know it I've ground a pile of heat(warpage) into what I'm working on. The oxy works well but the acetylene is so darned expensive. That's what led me to get a tig (yes I did get one), as with the work ahead of me I will get the use out of it. And as far as my goals are, I'm just trying to do the best job I can that will last the next 90 ish years haha

Does anyone have a recommendation for replacing the bottoms of these doors as to which to do first, the inner door frame or outer skin, or to do both at the same time?
Thanks again and Merry Christmas
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