Stainless Steel Fabrication

[opwan2002]

I am fabricating a brace for my Bow Sprit/Anchor Roller so that I can run an asymetrical spinnaker. In fabricating the brace I purchased a 7/8" bar and some 2" plate. If I grind or cut the material will I contaminate the stainless? Will it lose it's rust resisting properties? There will be some welding involved. Do I need to coat the finished brace with some kind of wax or solvent to add corrosion resistance?

[GordMay]

Unless all ground areas are to be passivated after grinding, the tools used (grinding discs, saw blades etc) must be ‘iron free’, and must not have been used previously on carbon steels.
Discs which are not iron free will impregnate the surface of the stainless with carbon steel, which will produce unsightly rust coloured staining on the stainless. This corrosion product in turn is corrosive to stainless steel, and will initiate attack of the stainless.

Most suppliers of metal working consumables have special ‘iron free’ discs for stainless steels.

You can also perform a simple test to ensure that discs are safe to use on stainless steel. A scrap piece of stainless is dressed with a sample of the candidate discs, then sprayed with tap water and left wet overnight. Satisfactory discs will not produce a rust coloured stain.

If all the ground areas are passivated after grinding, the contaminants introduced by the grinding consumables will be dissolved away, and it is not essential to use iron free discs.

[leftbrainstuff]

+1 to Gordmay's advice.

You also need to ensure that you don't mix different grades of stainless and that you select your filler material grades to avoid incompatible combinations. I only buy my stainless from reputable suppliers who can provide grade documentation. Without more details i can't provide specific advice.