Stick Welding Thin Sheet Metal

[David2011]

The lathe that I bought recently doesn't have a backsplash so I need to make one from mild steel. I by far would prefer to stick weld this project. Gas welding is my only other option at home and I don't want to gas weld this project. The AC welder is an old Lincoln, so old that it has copper windings. It only goes down to 40 amps. I have very limited experience stick welding anything thinner than 1/8" thick. I would like to use 20 or 22 gauge to keep the weight down; 18 gauge is an option if 20 or 22 is too thin. I don't see a backsplash needing a lot of structural strength. I can bend the backsplash in a sheet metal brake but the ends will be welded on. I'll also bend a self for tool holders and other small items from the same material. I'm thinking 4 " wide on the shelf.

What is the lightest gauge steel that is reasonable to weld at 40 amps with 1/16" 6013 with a reasonably good chance of not blowing through? Is there a better rod than 6013 for this application?

 

[Ulma Doctor]

The thicker the better in relation to blow through
DCEP will put the heat into the rod
DCEN will put the heat into the work
Stitch welding may be necessary if you have problems with travel speed and/or heat control

 

[woodchucker]

The lathe that I bought recently doesn't have a backsplash so I need to make one from mild steel. I by far would prefer to stick weld this project. Gas welding is my only other option at home and I don't want to gas weld this project. The AC welder is an old Lincoln, so old that it has copper windings. It only goes down to 40 amps. I have very limited experience stick welding anything thinner than 1/8" thick. I would like to use 20 or 22 gauge to keep the weight down; 18 gauge is an option if 20 or 22 is too thin. I don't see a backsplash needing a lot of structural strength. I can bend the backsplash in a sheet metal brake but the ends will be welded on. I'll also bend a self for tool holders and other small items from the same material. I'm thinking 4 " wide on the shelf.

What is the lightest gauge steel that is reasonable to weld at 40 amps with 1/16" 6013 with a reasonably good chance of not blowing through? Is there a better rod than 6013 for this application?

40 amps stick is hot for sheet. You probably need to use a copper spoon behind it to be able to fill those blow holes that you will have. if you can keep the spoon attached to the face that you are welding you might keep the puddle from blowing out. I made my spoon from copper pipe, annealed it, flattened it out on the anvil and then attached a handle.

You would need to stitch. I have a flux core, and it blows out very easily on sheet, even thick sheet. I had to weld up the rotted holes in my mower deck, and after blowing through, I came up with that idea, and had my wife sit on the other side , it worked, but it was tough.

 

[Jake M]

The lathe that I bought recently doesn't have a backsplash so I need to make one from mild steel. I by far would prefer to stick weld this project. Gas welding is my only other option at home and I don't want to gas weld this project. The AC welder is an old Lincoln, so old that it has copper windings. It only goes down to 40 amps. I have very limited experience stick welding anything thinner than 1/8" thick. I would like to use 20 or 22 gauge to keep the weight down; 18 gauge is an option if 20 or 22 is too thin. I don't see a backsplash needing a lot of structural strength. I can bend the backsplash in a sheet metal brake but the ends will be welded on. I'll also bend a self for tool holders and other small items from the same material. I'm thinking 4 " wide on the shelf.

What is the lightest gauge steel that is reasonable to weld at 40 amps with 1/16" 6013 with a reasonably good chance of not blowing through? Is there a better rod than 6013 for this application?

I have that welder. You're asking a lot of it to do stuff this small.

One workaround (if you can work with it.....), is while you can't (with any practicality, and ESPECIALLY with limited experience) weld 20 or 22 gauge metal directly, you can do a PITA workaround. If you make your corners with a piece of angle of the right length ( let's say 3/4 X 3/4 X 1/8 ish, or whatever. Nothing "heavy", you can let the angle make the corner, hold the sheet back an eighth of an inch (or a quarter), so the angle is technically inside, but "exposed" at the very point of the corner- Then, working from OUTSIDE the corner you can start a puddle on the angle without obliterating the sheet, then drag the puddle over to the edge of the sheet, so as far as the sheet is concerned, you got in and out real fast, even though you didn't.

Don't do this on the inside of the corner. Only from the outside, where the sheet is "backed up" by the angle.

It does (pretty much) require a careful drawing, or otherwise plan the layout precisely, as the angle does become a part of the overall dimension.

You will be tacking. Even with an appropriate welder you're gonna have a tough time making a full seam on flat sheets on the best of days, as all the stresses have no place to hide, so they end up as big ugly wrinkles.

What rod? What can you run best? I'd do what I said above with (literally) whatever one I had a surplus of. Probably 6010, 6011, or 7018,. The 6013 you mention is pretty smooth and predictable, it should do fine. I'd probably use 3/32 or 1/8, for no other reason than that's what I'm likely to have. 5/64 and 1/16 are technically better suited, but they're an art unto themselves to work with.

You would set the welder up to burn a solid weld into the angle, and bank on the quickness of "dragging the puddle onto the sheet" to make up for the insanely inappropriate weld that's about to happen to it.

If that sounds like something that might be within your skill set, have at it. If you aren't 100 percent positive, try playing with a small sample to see how it works out for you, maybe figure out how far to get the bead into the sheet before you back out.

 

[RJSakowski]

I welded up my own custom central heating duct work from 20g. galvanized by tack welding every 2 inches. You need to use only a momentary tack to prevent blow through. If you have a heavy piece of copper bar, placing it behind the weld will help to minimize blow through. Use as xmall a diameter rod as you can. Body shop supplies should have smaller diameter rod.

 

[Provincial]

You can sometimes find flat copper strips in electrical distribution equipment. They are used as bus bars, and sometimes have various holes for attaching distribution conductors. Undrilled bus bars are used where conductors snap onto the undrilled bars. The bus bars of high amperage devices are often quite thick, which is useful for heat dissipation.

My personal opinion is that 18 gage steel is the thinnest practical for shop work. Thinner material can be used in a production environment because tooling costs are spread out among a large number of units. 18 gage can be welded with a MIG (not flux core) with small wire, good technique, and patience. Stick welding and flux core involve slag, which is a real nuisance on sheet metal.

If you can make overlapping joints, don't overlook rivets or solder. Using enough rivets to hold things together while soldering is an age-old technique.

 

[David2011]

The thicker the better in relation to blow through
DCEP will put the heat into the rod
DCEN will put the heat into the work
Stitch welding may be necessary if you have problems with travel speed and/or heat control

None of that other than stitch welding is applicable to my AC only stick machine. I didn't say so initially but I only anticipated short stitches. That's how the backsplash on my other lathe is welded but it's a factory piece.

 

[David2011]

40 amps stick is hot for sheet. You probably need to use a copper spoon behind it to be able to fill those blow holes that you will have. if you can keep the spoon attached to the face that you are welding you might keep the puddle from blowing out. I made my spoon from copper pipe, annealed it, flattened it out on the anvil and then attached a handle.

You would need to stitch. I have a flux core, and it blows out very easily on sheet, even thick sheet. I had to weld up the rotted holes in my mower deck, and after blowing through, I came up with that idea, and had my wife sit on the other side , it worked, but it was tough.

I need a TIG machine. I welded a mower deck with TIG one time; super easy. I probably wouldn't use it enough to justify the cost, though.

 

[woodchucker]

short stitches can be done just by striking the arc, over and over, just move to different places and come back after it cools.

Have you thought of riveting?

 

[David2011]

I welded up my own custom central heating duct work from 20g. galvanized by tack welding every 2 inches. You need to use only a momentary tack to prevent blow through. If you have a heavy piece of copper bar, placing it behind the weld will help to minimize blow through. Use as xmall a diameter rod as you can. Body shop supplies should have smaller diameter rod.

That sounds very reasonable. I have some heavy aluminum, 1/4" and 5/8" thick. Wondering if that would do for a spoon.