Welding Tips and Tricks

Greetings dear friends,
Just wondrin' if there's any steel boat builders out there. I have many questions regarding electrolysis, galvanic effect etc and only a boat welder would know of these things. e.g Schools out if you leave mill scale on in a marine environment, I have witnessed this first hand and I'm restoring an 48 year old steel yacht made of high tensile steel and I need to know if i weld on a less noble in the galvanic scale, such as mild steel is it going to be schools out.

I've welded on quite a few steel hulls of various types - mostly work boats or tugs or fishing boats & the majority are made on regular mild steel - I agree the higher the carbon content the less severe the corrosion is but I rather think in the case of a yacht the use of a higher tensile grade is to allow the use of slightly thinner material as weight is a factor - from what I've seen all steel boats corrode very well no mater what you do ! - as to electrolysis this is more a factor of how much dissimilar metal is around & how many / how well placed / sized the anodes are plus keeping them changed - also if the boat lays up in dock connected to external power how well this is galvanically isolated - I've seen battery standby chargers & mains power wreak havoc.

THANKS NODDYBRIAN,
Even on deck with salt spray the demonic er sorry I mean galvanic effect is causing noble stainless to have gal fittings getting eaten. I've decided to ban all stainless !

A couple of places where stainless has been welded to the hi ten steel the steel has rusted up. Funny I went to welding school for a year I now realise I shoulda studied metalurgy. That was way back in 2013 and so much I didn't learn.
But man this welding stuff is great fun.

The stainless is far more resistant to galvanic corrosion which is precisely why its so prevalent in boat building. The lesser metal (galvanized steel, hi-ten steel, etc ) will always yield first. Salt and electricity will eat anything given the opportunity, and there's really nothing you can do about it.

Even aluminum structures will erode from salt and galvanic corrosion. Either build with wood entirely (and deal with rot) or have a strong discipline to service the boat regularly and treat rusting areas. Ah the pleasures of the sea...