correct wire for stainless?

[farmersfergie]

I am very much the novice at mig welding but I have been welding stainless exhausts etc very sucessfully with ordinary mig wire but need a little question answered before moving onto more structurally important items. Is there a special wire for stainless welding and what are the merits of using it over normal wire.

 

[Country Joe]

Welcome to the forum FarmersFergie!
As far as I know, if you weld with normal mild steel wire, the weld you have made will not have the same properties as the stainless that you're welding, so it'll rust at the weld.
Hope this helps.

 

[malcolm]

I've only ever used the generic stainless wire (from Halfords) for exhausts, but I think there are a few different types of stainless wire. The food industry is fussy about which type is used. Possibly this link will work for the vast selection offered by Lincoln: http://www.mylincolnelectric.com/Catalog/consumableseries.asp?browse=104|1640|Stainless%20Steel%20Consumables&locale=1033

You should really use pure Argon or a Helium/Argon mix for the shielding gas (such as BOC stainshield). I think that's because stainless steel is low in carbon and you can get a bit of carbon into the weld from the CO2 mixes which could cause a little rust later on. Having said that, for exhaust work I often use an Argon/CO2 mix.

Definately get the stainless wire though. It's no more difficult to use, and a weld with mild steel wire will just go rusty.

 

[Hitch]

A roll of 316L stainless wire, if its food grade work,
Or 308 for general purpose use.