Welding aluminum and/or stainless

[bluesman2a]

OK, this may be a dumb question, but here goes:

I have a mm251 and I want to know what I would need if I wanted to weld stainless and/or aluminum. I understand this is actually two different questions.

I assume that I would need a spool-gun at the very least (if possible at all).

This is merely for hobby-welding, and will not be structural or critical in any way.

Another question while I'm at it: why does one use a spoolgun? I assume it's for material not stiff enough to be PUSHED through a liner to the gun, so it must be spooled?

[Dan]

You don t need a spool gun for stainless. Stainless wire is more than stiff enough to be pushed thru your standard liner & gun assembly that came with the machine. Ideally, when switching from steel to stainless wire you should use a different liner or have a second gun and cable asssembly around for the stainless wire. The poor mans (LIKE ME) solution is to just blow the existing liner out real well with compressed air before installing the stainless wire. For short circuit transfer with stainless, I use a 90% helium 7.5% argon 2% CO2 shielding gas.

[bluesman2a]

Originally posted by Dan
For short circuit transfer with stainless, I use a 90% helium 7.5% argon 2% CO2 shielding gas.

Thanks for the reply Dan. Can the same bottle/regulators be used for this mixture? I typically run 75%Argon 25%CO2 currently. Or are they typically a different thread?

Any other caveats for welding stainless? Is it any more difficult than mild steel?

[Guest]

You can use tthe same regulator for C-25 and Tri Mix gas. Stainless is a little harder to get it looking nice....but basically the same. The weld should be a brownish gold color, if everything goes right.

[Roger]

CGA-580 fitting is for inert gas. It is used for Nitogen, Helium, and Argon. It is also used for welding shielding gas mixtures with inert gasses and O2 or CO2.

CGA-320 is for CO2 gas.

You can buy adapters for about $10. Using adapter, regulator with CGA-580 fitting can be used on CO2 tank's CGA-320 fitting. With a different adapter CO2 regulator can be attached to Argon tank's CGA-580 fitting but some CO2 regulators are only rated for 1800psi. For that reason gas dealers would rather not sell that adapter.

[Dan]

I had some scrap peices of 1/4" 304L SS left from a project that I was working on this evening. So since I was using my MM 185 to do the welding on this project I went ahead an ran a few beads on the scrap. Bluesman2a I ran these for you because I wanted you to see the color that Rocky D mentioned. The pictures that I m attaching are what the weld bead looks like right after you complete it. To make the weld bead shiny just take a SS wire brush to it. I generally use a SS wire wheel on my cordless drill.

Also, the filler wire that I used for these welds is ER308L- Si. I like this wire much better then a standard ER 308L, because the added silicon makes the weld puddle wet out better.

Anyway here are a coup[le pictures lets see if the colr turns out right.

[Dan]

I had some scrap peices of 1/4" 304L SS left from a project that I was working on this evening. So since I was using my MM 185 to do the welding on this project I went ahead an ran a few beads on the scrap. Bluesman2a I ran these for you because I wanted you to see the color that Rocky D mentioned. The pictures that I m attaching are what the weld bead looks like right after you complete it. To make the weld bead shiny just take a SS wire brush to it. I generally use a SS wire wheel on my cordless drill.

Also, the filler wire that I used for these welds is ER308L- Si. I like this wire much better then a standard ER 308L, because the added silicon makes the weld puddle wet out better.

Anyway here are a couple pictures lets see if the color turns out right.

[Dan]

And here is the 2nd picture.

[R. Nelson]

stainless steel

Originally posted by Dan
And here is the 2nd picture.

Dan, when setting up for stainless are the weld settings comparable to carbon steel or do you run hotter?

[Guest]

I forgot to add that the tri mix gas sounds different than other gasses.

Good looking welds, Dan!

[Srubrn]

Dan,

What kind of pattern were you using? My welds don't so neat. I usually use a z pattern.

[Dan]

Re: stainless steel

Originally posted by R. Nelson
Dan, when setting up for stainless are the weld settings comparable to carbon steel or do you run hotter?

The stainless puddle is kinda sluggish. It does nt wet out as well as a steel puddle being shielded by C25. So generally, you run at least a higher voltage setting.

[Scott V]

Inductance.

A machine with a inductance control is a big help with wetting out the puddle.Dan have you ever used 316L fluxcore it's kind of nice stuff.I picked up a 25lb roll for $20.00 at a welding show/clearance.With this wire you use 75/25 gas.You peel the flux off for a very brite looking weld.The brand was Alvesta.

[Dan]

Originally posted by Rocky D
I forgot to add that the tri mix gas sounds different than other gasses.

Good looking welds, Dan!

Thanks Rocky

I run a few SS GMAW welds during a week

The weld puddle definately takes a little time to get use to. You should see the beauties that the guys I work with produce, and they are pulling $14 to $17 an hour.

[Dan]

Re: Inductance.

Originally posted by Scott V
A machine with a inductance control is a big help with wetting out the puddle.Dan have you ever used 316L fluxcore it's kind of nice stuff.I picked up a 25lb roll for $20.00 at a welding show/clearance.With this wire you use 75/25 gas.You peel the flux off for a very brite looking weld.The brand was Alvesta.

Until we got our MM 185 at work I seldomly short circuit transfered SS, because our older MM 250 runs SS wire so poorly. The weld puddle wets out nicely with the MM 185, and the older MM 250 wants to produce a narrower weld bead that has a high peak to the center. Now in the past we rented a MM 130, when I was putting a SS liner in one of our large browning ovens, and it produced results similar to the MM 185. I might just have to get myself a bottle of Tri mix and see how my MM 210 does too.

I haven t tried the gas shielded fluxcore wire yet. However Im going to try and convince the boss that I need a roll of it around for certain jobs were the material is to thick for short circuit transfer, and out of position were spray transfer isn t possible. Most of our SS is either 304 or 304L, so I would be going with a 308 filler wire.