The Stovebolt Site Forums The Shop Area Paint and Body Shop Sheet metal welding, which kind is best?

Pick up an almost orginial 1964 C10. Has rust in rockers, and behind front wheels.
Questions are:
1. What type of weld does best on sheet metal? I have mig (gas), tig, and can gas weld. All Miller except the gas. The hot rod shows and mags show all three in use, just don't know which is best.
2. Replacement body panels. Who makes them that fit right out of the box? I don't want to spend my time with hammer and dolly when I paid for correct fitting panels.
Thanks

I spent quite a bit of time teaching auto body repair, using a Miller MIG welder with CO2 gas shielding as our primary method of welding panels. The trick is to use as small a diameter of wire as possible, low heat, and don't try to run continuous beads. Stich a short weld, then move several inches away for the next stitch. There will still be a little distortion that will have to be ground and planished away, but the less you warp the metal, the better.

50-something years ago, body panel welding was done with an oxyacetylene torch and bare steel fill rod. That's how I learned the trade, along with just a little experience at lead alloy body solder as filler. I had an older cousin who was an artist with lead- - - -I never got close to his skill level!

Just about all the repop body patch panels are poor imitations of OEM parts- - - - -I think they all come from the same sweatshop somewhere in India or China!
Jerry

MIG on low setting, low wire speed. Put a few test panels together to test for depth of weld, etc. Be sure to adher to the warpage rules you use (skipping around to the coolest part of the panel) when you grind as well.

Mig is my go to for just about all of my usual fab work except aluminum. Got to admit, it's also the easiest to learn.
Several years ago I was working on a door. The PO had buggered up the garnish molding screw attachment hole around both windows. I decided to mig a small amount a metal into the buggered holes to ' close' the hole up a bit. I quickly realized how hard the mig weld material was. The sheet metal screws were not about to cut new threads through the welds. It took some work to get the hole round again.
I worry about hammering the mig stitch welds flat. Test panels sounds like a good idea. I'll try the different types on the panels and see what works for me.
Off shore stuff again! I've had two incorrectly machined wheel cylinders and an incorrect starter solenoid in the past two weeks.

The type of wire you use and the temperature it's applied makes a big difference in how hard the final weld will be. Flux core wire has a habit of getting harder than woodpecker lips! CO2-shielded mild steel wire, especially .023" diameter applied just hot enough to bond well can be hammer-worked a lot easier.
Jerry

TIG is slow and harder to master, but the welds are softer than MIG welds, making them easier to planish and grind. The foot pedal allows you to control the heat to find that sweet spot for creating a perfect tiny dot weld which we look for. TIG doesn't splatter, making it difficult to set your shop on fire.
Carl

I want to learn to TIG. I can see a need for it in my shop. The local welding shop tells me that TIG is hotter and warps easier, but I do not know if he was being truthful first hand. He also said that you have to have the metal connection points very VERY clean. I have done zero research on TIG and do not even know if I need AC or DC TIG, which is the most useful/common, and what shielding gas you use. I just know it is very clean welding process that would probably be a good investment.

Link to 100 pages on panel repair.......this guy is a master:

http://www.garagejournal.com/forum/showthread.php?t=182565&page=98

Same shop with detail on a fender repair:

http://www.garagejournal.com/forum/showthread.php?t=182565

As Jerry says: Sometimes it does not matter where you buy the patch panel, it does not fit exactly. It's either the truck or the panel or both at fault. You can always make it work. It's a common issue.
Also, what I have found is best is little dots of mig connected together. Slightly stacked. (3/16-1/4 dia.) Like Jerry said, do them several inches apart. This is where us novices should take note. We don't understand how important it is to make them way, way apart, and even then, wait until the recent spot is cool. Jerry can do it, we can't. We only have a few panels to do on one truck. Got plenty of time. Us novices are in a hurry to keep welding to get it all stitched. If you don't slow down and wait for each weld to cool you will warp the panel and then you are done. You are in BIG trouble. It may all have to be cut out. If it takes hours to do it slow, so what? Small pieces and pieces with bends are more forgiving than a big flat panel regarding warpage. Don't spend all that time trimming, aligning, clamping just to warp the thing. SLOW and easy. Use the flattened end of a copper pipe behind the weld if there is access. Bend it to shape up behind. Weld won't stick to it. It helps to fill a blowout and etc.
75/25 gas, Argon/Co2 is better for thin metal/body work. Most mig'ers use 75/25. %100 co2 is too hot for thin, unless you are experienced. It's all done with butt joints and they should be butt tight! Credit card gap or thinner. If you use butt clamps, grind the blade down.

I can warp a panel with a wooden match, or a TIG, or a MIG. You have to become competent in whatever welder you select, and that takes a lot of practice. MIG and TIG requires two vastly different skill sets to be competent at each of them.

Uh, do we have a difference of options here from two of the 'journeymen' on this forum?
Hotrod thinks CO2 with very mild small diameter wire is the trick. Bartamos seems to think CO2 is too hot for thin panels and think 75/25 would be a better fit for us, 'the unknowning'.
I have no pure CO2 bottle in the shop but that's just a money thing. I have used 75/25 on all my mig projects so far and don't remember the wire number but that's just another money thing.
I guess the old saying applies, "There's more than one way to skin a cat". I just have to find the right knife.

Jerry is the journeyman. He can weld with a 12V battery and a clothes hanger or any gas mix. I try to give info and experience from a novice perspective. Info that a novice will have better luck and not have to buy a lot of equipment. I study the best I can and read. When I want welding info, I go to welding forums. They have communities of low to hi experience welders. I have welded patch panels with Mig 75/25 AKA C25. %100 C02 will have better penetration. Penetration is not really a problem on thin. The varied info is not meant to create a negative towards anyone. It gives alternates to explore and study to see what may suit a posters ability and funds. All info I've ever read from Jerry works. None is BS. He just doesn't always keep his motorcycles in the upright position.

So noted. I respect and welcome views from everyone. Knowledge from those who have been there and done that is invaluable, realizing that not everyone takes the same path but gets there just the same.

That's the Forum in a nutshell. Wish I would have said that.

Thanks for the vote of confidence, Bart! There are all sorts of approaches to welding, and every situation is somewhat unique. I did 2" to 6" stainless steel thinwall tubing welding for the world's largest winery, E & J Gallo, in Livingston California for a while, plus black iron pipe welding for the same outfit, anywhere from 2" to 12" diameter stuff. The stainless was done with Argon-shielded TIG, with Nitrogen filling the inside of the pipes for a 100% penetration weld with no fill rod and pipe ends machined to have a hairline fit in an alignment fixture. We used a Tungsten electrode ground to a needle-sharp point and the width of the weld bead was less than 1/8" with no buildup above the surface.

If I was welding patch panels onto somebody's vintage Rolls-Royce bodywork, I'd probably use a similar procedure, and the labor charge would be proportional to the customer's depth of pocket. It wouldn't be cheap! For routine body work, CO2 shielded MIG works very well, and it's affordable, and not too hard for someone with moderate experience to learn to do acceptably.
Jerry

75/25 is what I use for everything MIG. I adjust my technique to compensate for the differences in thickness. If you use an Easy Grind wire like Lincolns SuperArc L-56 (.025) you can't really get any better. The nice part about adjusting your technique to compensate is you can use 75/25 and .025 wire on everything there is (mild steel). On the thick stuff like hitches, double pass welding techniques, on thin stuff like what I am doing now...

http://forums.devestechnet.com/foru...0-tip-of-the-week-38-for-june-19-25-2016

Cut the power way down, wire speed way down, keep the welds clean and skip to the coolest part of the panel with about 1/4" stitches each tack, and you are good to go. A very handy vocation to learn for all ages and you can do it on a Lambo or an old Chevy truck with the same great results.

There is also another Mig. wire you can get if your welding supply is out of Lincoln Easy Grind and its called Spool Arc EZ Grind by Hobart it comes in .024. It has the same quality as the Lincoln wire.

Good thread fellas. Never heard of the EZ grind wire or hammer welding (more on HAMB)....sounds like perfect for body panels, but need to change out the wire if doing something structural.

I use .030 C25 @ 11cfh. What I have found that works best for me is to do the first tack then hit the root of that tack at a 45 degree angle on the next trigger pull, that way your hitting much thicker material and it still flows into the gap and do that for an inch , then immediately grind the bead off so it doesn't shrink the panel nearly as much as if you left a big bead on it.

Another thing I have also found is that the bead continues to shrink until its dead cold some times taking as much as 24 hours to stop shrinking. The larger the bead the more it shrinks the panel in that spot. So grinding before you stop for the day helps.

That's what the HAMB thread indicated about Hammer welding Dave, weld 2-3 spots, then use hammer on dolly on the weld to offset some of the shrinking effect.

There are many times you can't get a dolly behind it and if your not careful hammering Mig welds will crack it and be unseen to the eye but not the rust. The heat from a Tig anneals the weld so you can hammer it if you can get behind it.

When I grind I let the spot get red hot using a lot of pressure so it anneals the weld, Using a shrinking wheel after grinding seems to do the same thing. It works magic on a panel that you welded and it starts oil canning.