Tip/liner/drive-roll set-up for sheet metal?

[bluesman2a]

Now that I got the old 251 sparking right, I'm moving on to bigger/better things. I read some stuff about sheet-metal work here, and the consensus seems to be that .023 is the stuff to use to keep the heat transfer/warping down.

Application: 16 ga sheet metal lap welded (I think it's "lap" joint, it's laid on top, and a bead run along the edge) to the flat edge of a 1.5", .120 wall square tube. For those of you who read my other post, this will be the top/front edge of my new desk.

Questions:
1) I have the .023/.025 drive roller, but they sold me Hobart .024 wire, is this a problem? Which groove should be used? Will this fit through my .023 tips?

2) I bought a 15' .023-.025 liner, is that the right length for what came standard on the 251? If it's not, can I cut it without bad result? The welding-shop guy said it wouldn't be a problem.

3) I want to run a nice bead all the way down the length of the top/table so it's smooth and not irritating to the touch (think typing on this thing, with your wrists resting on the edge). I want to minimize warping when doing this. Any suggestions on technique for this?

Thoughts, comments and concerns appreciated.

[Scott V]

The wire is fine,that's just a attempt to confuse people.Seems like it's working!

I think you would be fine with .030 in that guage your working with.

All the liners come in 15" lengths.just cut it with some side cutters.Make sure you cut it the right length,not to short or long.Look at the gas defuser to see how long to cut.Too long is real bad.Also hold the cable straight before you cut it.

The last one you are on your own on that.

[Bob]

If possible you might want to do the "hand rest" edge last; after the practice on the other edges. The .120 box tube will make this a lot easier than a butt joint of the sheet metal alone.
Good Luck
Bob

[morpheus]

I think if it were me I'd pull the top sheet of metal back about 1/8" from the edge and add enough filler to join the two surfaces then grind it flush/round the outer edge a bit with a 4.5" sanding disc. I say sanding disc and not flapper wheel because with a sanding disc you can come much closer to getting a surface flat than with a flapper wheel. since the sanding disc has the solid rubber backing pad.

good luck.

- jack

[cope]

.023/.024/.025-all the same. Position the feed roller so that the .023/.024 is facing out on the shaft and you will be set-up. If you have a .030/.035 roller, you need a different one. Here is (Hobart's I think) a nice wire size chart.

[craig]

i think your going to find some warping. i did some sheetmetal work on my mustang over the winter. if you just do tacks all along the seam, you'll be fine. if you try to run one long bead it may be a lesson. depends on what your doing. mine had to be perfect because of the high gloss of the clear coat (any waves will show up). gotta love body filler! experiment and have fun!