[yachtweld3mm]

Gidday,
My steel yacht has many perfectly welded stainless fittings welded to the steel deck. Except one. The compass was mounted on a stainless 4 inch RHS (square pipe) welded to the cockpit floor. It was the only rust on the boat when I bought it and it actually ate part of the deck.
(Note yacht cockpits are oft full of salt water creating a serious electrolytic reaction)
The builder welded for a living - I don't.
Should an amateur welder stay away from stainless to mild steel welding>?????

[cj737]

Just use 309 filler wire and have at it. Clean everything exceptionally well prior to arcing off.