Stainless MIG question

Short stickout on your wire, because ss is a poor conductor. Bevel and preheat thicker pieces (1/4" and greater). Better results with tri-mix gas, but a small project probably wouldn't justify the cost. Use the heat tint removal paste if you need to get rid of the rainbow.

Whatcha building?

Crowns/coronets. Similar to the ones lower down on this page:

Probably won't get much over 16 ga thick. I'm not sure of the alloy, but I don't think it is 400 series, probably 300 series. My wire is 308L. And yeah, it probably won't be worth getting tri-mix unless my friend winds up getting a lot of business (not the site listed...I have no connection with them). If it is, I've got an account at the local Airgas, so no problems finding it.

Thanks for the tips!

You should be fine with that setup, just keep it tight. I haven't been to a RenFest in quite some time. I bet the boy would dig it.

Good luck!

Passivation? Why would you think you need it passivated? Unless you are cutting or abrading it with carbon steel and you are then very concerned about minor rust spots you need not worry.

Any time you weld a stainless steel you will get disassociated iron particles on the surface of your weld.

Stainless steel is still a steel alloy. It is mostly iron. When you weld these steels you disrupt the metallurgical balance, and some of the iron separates from the nickel and chromium.

If the welded piece is never exposed to anything reactive, like salt water, then it may never rust, but usually the moisture in the air is enough to eventually bring out these rust spots.

The worst bit is that these rust spots can cause iron underneath them to also react, acting like a cancer on stainless welds.

No idea. I don't know what alloys you are welding, under what conditions, for what purpose.

I'd really like to see the SS-wire that the *manufacturer* says can be welded with mix gas. SS is low carbon, mix-gas has CO2 and some of that C will later be found in the weld.

Any stressable references?

Nick