Tig welding door panel questions

[Bob C]

Originally Posted by Corley

Off topic, but what's the deal with those wooden spoke wheels?

That's a Canadian AA. The wheels rear axle and drive line are different
than US trucks.



Bob

[Tinbasher]

To answer your questions. Yes TIG is a nice way to go, but you have to take your time. It is slower than Torch or MIG welding. Fit is very important. You need to get your panel fit as tight as possible. When rebuilding the door, you need to repair the inner strucuture first. Then fit it to the opening and check the fit. Lenght, Width and Height. When everything fits nicely then you can install the outer skin. The Cab will need to be installed on the frame to do your fitting. First make sure the frame is level and square.
Now you can weld in the outer skin. Make sure you Tack the panel into place. I like to make my Tacks about 1/8" and space them out along the panel until the tacks are about 3/8" apart. Then you can weld between the tacks. A good way to support the weld area is to make up a Hardwood support the shape of the panels along the weld. A piece of 2x4 hardwood will work well. This has two advantages as it holds the panel into place and you can hammer against the wood to sink the weld. If the weld sinks to far then you can remove the wood and hammer and dolly the panels back into shape. You shouldn't make your next weld until you can place your hand on the metal surface without burning yourself. Some guys will use a air gun to cool the weld, to speed things up. A Door skin on a "A" will usually take 6 to 8 hours to do the welding and cleaning up. Go slow in the beginning, it may take you three times as long to do this as your learning. Good luck with your project, if you have any questions feel free to drop me a line. I've been doing metal work for 45 years so I have a few tricks I can pass along.

JP. "The Old Tinbasher"

[deuce5wndw]

As I have aged I have a hard time seeing through a shade 10 lens! Make a pretty weld with my mig, one you would show to your friends only problem it isn't holding anything! I bought a Cobra torch and gauges and love using them! Last time I got glasses I got a pair of prescription shop glasses with bifocals at the top and bottom but still couldn't see good through the helmet. I bought a shade 5 flip up lenses for my shop glasses and the Cobra torch and it sure makes it easy again for sheet metal work. So my vote goes to OA for sheet metal work.
Dale

[johnneilson]

Deuce,

You are absolutely correct, seeing what you are doing is absolutely essential.

As with some of the "myths" told here, you might look into some of the better self darkening lens assemblies. The better ones are shade adjustable and response time adjustable. Not to mention that vision correction lenses are made to fit inside the helmets.

Enjoy the Holidays, John

[Flathead Fever]

I took a autobody class 40-year's-ago from an old time body man that was an amazing metal finisher. That is all he had done since 1948. You definitely want a butt weld. You want the pieces as close together as you can get them, no space at all. The less filler rod you add the less warpage you will get.

He was teaching us to hammer weld with gas welding but there is so much warpage with that much heat the TIG is the way go. I just bought one but have not started practicing with it. When we gas welded we tacked one end and then quickly hammered it with a body hammer and dolly. Then tacked the other end and hammered it. Then staggered the tack welds every half-inch and hammered the tacks. Then weld a half-inch at a time and hammered it while its hot, you need to be fast. The move to a different spot while the other one cools down. If your really good the weld disappears. We had a one gallon can of this stuff called moistbestos which just by name I can guarantee you does not exist anymore. It was like Playdoh and you put it around the weld to absorb the heat from spreading further out into the sheet metal. Anything you can do to try and control the warpage. Eastwood sells a similar product but I have not trid s it yet. I heard people to say to use drywall mud. Anything you can think of that you can put around the weld area that will stick to the metal and absorb the heat.

We had piles of donated junkyard fenders to work on in that class. It makes a big difference when you can practice on metal you have no emotional attachment to. We would cut slits and weld them up. Smash dents and then try and metal finish them. If you want to learn mess with a junk fender. If you practice on a junk fender everyday for a week or two you will be amazed how much better you get. Watch the welding videos on youtube so you will know what you are doing wrong. The problem I'm having is with a cornea transplant I had because of a botched Lasik eye surgery. That one eye is so blurry I'm seeing double vision with it. Nobody has been able to fix it. I see two-welding puddles.

[Terry, NJ]

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"Moistbestos"? LOL! Yup, by name alone, It's long gone! To help prevent warpage, I like to space the pieces for the first tacks about one welding wire thickness apart. It'll close up! Start by tacking the extreme ends of the part. Parts that are too tight/close in the beginning usually distort by the end of the job. Clamping the work keeps the work in the same horizontal/vertical plane and that makes for less grinding and filler putty. Tacking is a series of 1/2 to 1 second bursts. There should be some melt through to the backside of the panel. This guarantees good penetration. Stress relieve the welds with a SMALL hammer and a block of steel the buck the strike. B.F.Hs (Big F**king Hammers) will distort the body metal. The weld it's self may be hard, but the H.A.Z. (Heat Affected Zone), the area right around the weld will be soft and easy to bend/distort. I like to make my my patch panels from 18 ga. Ford used 19 ga. As far as I know, 19ga is unavailable today. In some cases, I will even go up to 16 ga, especially if I think there will be a lot of grinding. The thicker the material, the less chance of blowing through. For large holes in the firewall, I ground them out a little and fitted a slug from an electrical junction box, with some grinding, they were Perfect!
Practice Makes Perfect!
Terry

Originally Posted by Flathead Fever

I took a autobody class 40-year's-ago from an old time body man that was an amazing metal finisher. That is all he had done since 1948. You definitely want a butt weld. You want the pieces as close together as you can get them, no space at all. The less filler rod you add the less warpage you will get.

He was teaching us to hammer weld with gas welding but there is so much warpage with that much heat the TIG is the way go. I just bought one but have not started practicing with it. When we gas welded we tacked one end and then quickly hammered it with a body hammer and dolly. Then tacked the other end and hammered it. Then staggered the tack welds every half-inch and hammered the tacks. Then weld a half-inch at a time and hammered it while its hot, you need to be fast. The move to a different spot while the other one cools down. If your really good the weld disappears. We had a one gallon can of this stuff called moistbestos which just by name I can guarantee you does not exist anymore. It was like Playdoh and you put it around the weld to absorb the heat from spreading further out into the sheet metal. Anything you can do to try and control the warpage. Eastwood sells a similar product but I have not trid s it yet. I heard people to say to use drywall mud. Anything you can think of that you can put around the weld area that will stick to the metal and absorb the heat.

We had piles of donated junkyard fenders to work on in that class. It makes a big difference when you can practice on metal you have no emotional attachment to. We would cut slits and weld them up. Smash dents and then try and metal finish them. If you want to learn mess with a junk fender. If you practice on a junk fender everyday for a week or two you will be amazed how much better you get. Watch the welding videos on youtube so you will know what you are doing wrong. The problem I'm having is with a cornea transplant I had because of a botched Lasik eye surgery. That one eye is so blurry I'm seeing double vision with it. Nobody has been able to fix it. I see two-welding puddles.

[BRENT in 10-uh-C]

A couple things to add. Terry is correct that positioning is a great way to control heat. There are plenty of anti-heat damming compounds on the market, -and Eastwood carries one version. As far as 19 gauge is concerned, I generally purchase 10 sheets at a time ever year from Central Steel & Wire in Chicago. Others likely carry it too.

And finally, if you are experiencing warping, there are likely two issues affecting this. To begin with, the fit between both pieces of metal is poor, and second the replacement panel has not been properly tack-welded or clamped to the parent metal. One final thought to think about, while an argument sounds logical about acetylene being expensive, ...how much acetylene do you use with a small 00 or 000 tip with a soft carborizing flame, -and how much are the consumables for a MIG costing?

[M.W.Miller]

I too have been fixing a pair of 28 ccp doors. much trial and error. with one almost done. My method for this was fit both patch panels as I went along. starting with the outer panel. lining up the edges is a bit of a challenge because the profile of the crown on the edge is not as flat as the original. Also the doors are not of equal vertical length. so keep this in mind; your cut\weld line will be at a slight angle. I welded with a strait cut and had to split the end at the bottom corner to get the corner crown to line up. Once I had the outer patch panel lined up and the curve lined up with the cab, " on the cab off the cab"as needed. I started to fit the inside panel. and got it to match up as it should. This should be done before any finish welding is started. As stated earlier in this post it is very critical that the cab is square with the wood correctly in place. also all hinges need to be in proper alignment. lots of pre-prep to get a good fit and finish. At an additional cost a whole door skin which welds at the belt line might be overall easier to patch. My thought is too keep mas much of the original metal as you can. hope this helps.

[Terry, NJ]

I had a bottom of a front seat of my Town Sedan that was shaggy. I used a piece of metal pallet strapping and cut the old rusty metal to a depth equal to the width of the strapping. It worked fine!
In regards to the MIG, I don't know what problems you've all had. But I've welded every way you can weld (Except submerged arc and plasma) and I've never had any problems with it. One thing I want to try is a lap weld where you bevel the edge of both pieces and hit it with a spot welder. Bevel the edges so you can lap them slightly and weld it. Don't know if my description is very clear, But that's it. There would be no distortion or pulling.
Terry

[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 [/QUOTE]

[BRENT in 10-uh-C]

Terry, I think the difference between what we are suggesting and what you did is "metalshaping". If you MIG a panel, the weld becomes hard & brittle which makes planishing and stretching/shrinking almost impossible. There are some that will compensate for this shortcoming by applying extra thicknesses of body filler over the top.

[Terry, NJ]

Brent, The CO2/Argon shielding gas prevents (or it's supposed to) the hydrogen that makes the welds brittle. The welds break because they aren't penetrating enough. Too many "welds" are little more than "solder" , just attaching it's self to the surface of the metal. Or the H.A.Z. allows breaks away from the parent metal. In the first case, the weld must penetrate through. This must be confirmed visually. The whole welding process is a dance between heat and duration. Then all those little bumps must be ground. I have tried planishing and without some instruction, I have had no success. As I understand it, you're striking the metal with a relatively light hammer to bring down high spots. But it's kind of a glancing blow. This is the forte of the French blacksmiths who created the folds and wrinkles in the Statue of Liberty and the "Trench Art" that was created from old brass shells after WW2. "Metal shaping" at it's best! I believe the technique is called Repogee or something close to it.
Terry

Originally Posted by BRENT in 10-uh-C

Terry, I think the difference between what we are suggesting and what you did is "metalshaping". If you MIG a panel, the weld becomes hard & brittle which makes planishing and stretching/shrinking almost impossible. There are some that will compensate for this shortcoming by applying extra thicknesses of body filler over the top.

[BRENT in 10-uh-C]

Terry, actually it is the CO2 that is embrittling the metal. We use Argon in TIG-ing without a problem.

As for planishing, all three metals need to be the same hardness to successfully planish them. You are basically stretching the metal where it shrank during the heat-cooling process. Also, planishing does not only need to be done with a hammer & dolly, it can also be done using a wheeling machine.

[johnneilson]

Originally Posted by Terry, NJ

Brent, The CO2/Argon shielding gas prevents (or it's supposed to) the hydrogen that makes the welds brittle. The welds break because they aren't penetrating enough. Too many "welds" are little more than "solder" , just attaching it's self to the surface of the metal. Or the H.A.Z. allows breaks away from the parent metal. In the first case, the weld must penetrate through. This must be confirmed visually. The whole welding process is a dance between heat and duration. Then all those little bumps must be ground. I have tried planishing and without some instruction, I have had no success. As I understand it, you're striking the metal with a relatively light hammer to bring down high spots. But it's kind of a glancing blow. This is the forte of the French blacksmiths who created the folds and wrinkles in the Statue of Liberty and the "Trench Art" that was created from old brass shells after WW2. "Metal shaping" at it's best! I believe the technique is called Repogee or something close to it.
Terry

Bingo, done properly MIG is fine. Of course, to be done properly, you must use proper wire, heat and shielding gas. CO2 is not the only one, 75/25 mix and TriMix is available also.


J

[BRENT in 10-uh-C]

Originally Posted by johnneilson

Bingo, done properly MIG is fine. Of course, to be done properly, you must use proper wire, heat and shielding gas. CO2 is not the only one, 75/25 mix and TriMix is available also.


J

John, just exactly what are you implying is the 'correct' shielding gas??

To my knowledge, 75/25 mix has 25% CO2 in the mix, --so that does not help eliminate the issue, ...and Tri-Mix has the Argon too, the same amount of CO2 gas, and Helium is added to the mix. Again, the CO2 is what embrittles the weld.


FWIW, we have used MIG wire from a spool in lieu of TIG wire on many occasions and we cannot tell a difference when planishing the welds, -which proves it is not the wire.


I know we keep discussing this "MIG is considered proper" mindset, so instead of taking my word on the CO2 being the issue, why don't y'all pose this question on one of the sheetmetal panel-beating sites which is filled with professional panel fabricators to see what their opinion is.


.

[Terry, NJ]

Brent, I confess to incomplete knowledge of all the chemistry of this situation, but I believe it's the hydrogen that causes brittleness in welds. Once this was discovered, a series of rods ( stick ) was developed called "Low Hydrogen" The most well known is 7018 but there are others such as 7014, 7016 and 7024. 7018 is an all position wire, while 7024 is basically for flat welding. Oh God, I'm straining the memory cells! It's been a while! Anyway, IIRC the purpose of the low hydrogen was to keep the the gas out of the weld. I don't believe it was the CO2 that was embrittling your welds. It may have been your cooling down of the welds after completion. MIG does cool much quicker. But thats because there is less heat generated. While the TIG may have a duty cycle of as much as twenty or thirty seconds and the accumulated heat slows the cooling down. The MIG may have a duty cycle of as much as 4 or 5 seconds and the heat doesn't build up as much, yet the heat at the point of the weld still generates molten steel, just not as much of it, so, you get a hard point at the weld. I'm just speculating on a problem I've never had. I hope this helps!
Terry

[BRENT in 10-uh-C]

Originally Posted by Terry, NJ

Brent, I confess to incomplete knowledge of all the chemistry of this situation, but I believe it's the hydrogen that causes brittleness in welds. Once this was discovered, a series of rods ( stick ) was developed called "Low Hydrogen" The most well known is 7018 but there are others such as 7014, 7016 and 7024. 7018 is an all position wire, while 7024 is basically for flat welding. Oh God, I'm straining the memory cells! It's been a while! Anyway, IIRC the purpose of the low hydrogen was to keep the the gas out of the weld. I don't believe it was the CO2 that was embrittling your welds. It may have been your cooling down of the welds after completion. MIG does cool much quicker. But thats because there is less heat generated. While the TIG may have a duty cycle of as much as twenty or thirty seconds and the accumulated heat slows the cooling down. The MIG may have a duty cycle of as much as 4 or 5 seconds and the heat doesn't build up as much, yet the heat at the point of the weld still generates molten steel, just not as much of it, so, you get a hard point at the weld. I'm just speculating on a problem I've never had. I hope this helps!
Terry

Again, we'll beat this horse a little more. The shielding gas is only there to prevent oxidation, -not to aid cooling. Again, there has been much study by craftsmen who have the talents to fabricate Model-A sheetmetal in exacting aesthetics that will tell you that a MIG is not the tool of choice. On the other hand, you have expert Model-A restorers that will tell you they do it without a problem. I guess it is much like installing a head gasket on a Model-A, ...some will tout they installed many gaskets tightening the head nuts only using an adjustable Crescent wrench, -and others suggest it is better to use a properly calibrated torque wrench. People will only believe what seems believable to them, so my attitude these days is do whichever way you believe. There will always be someone around to re-do the job at a later time. Lord knows that is why we are so busy re-restoring 'restored' Model-As these days.