G
Guest
Guest
Will painting my 316 stainless steel home made p-brackets with epoxy paint before antifouling protect from corrosion, & is it wrong to do the same to the propeller shafts?
brianhumber
New member
These steels do not like depleted oxygen environments. Its why you see pits in shafts inside cutlass bearings that are left stationary for long periods in water for example and we had lots of trouble in oil tanker cargo tanks with pitted ss valve rods when inert gas at 3% oxygen or less was introduced in the 1970s to stop us blowing up.
G
Guest
Guest
I agree with Brian.
SS needs oxygen to maintain the oxide film that prevents corrosion so covering it seems never to be a good idea.
I'd also re-think whether or not I wanted to anti-foul as well for the same reason.
) Ian D
SS needs oxygen to maintain the oxide film that prevents corrosion so covering it seems never to be a good idea.
I'd also re-think whether or not I wanted to anti-foul as well for the same reason.
) Ian D
charles_reed
Active member
Hope you made them out of A2.
Don't cover them with ANYTHING, epoxy, antifouling or anything else.
If not 316 A2 watch out for crevice corrosion - you'll see it within a few weeks especially if you have an aluminium-bronze prop.
Don't cover them with ANYTHING, epoxy, antifouling or anything else.
If not 316 A2 watch out for crevice corrosion - you'll see it within a few weeks especially if you have an aluminium-bronze prop.
G
Guest
Guest
A2 and A4 are merely the german specifications equivalent to the uk 304 and 316
both depend on oxygen to maintain the protective coat that makes them stainless. without oxygen, they corrode at least as badly as mild steel. since it is unlikely that you can put an epoxy coat on the metal that will give 100% coverage and remain like that, then leave stainless bare.
incidentally, the problem with oxygen means that you should never use stainless in wood that might become wet, or indeed in grp below the water surface
both depend on oxygen to maintain the protective coat that makes them stainless. without oxygen, they corrode at least as badly as mild steel. since it is unlikely that you can put an epoxy coat on the metal that will give 100% coverage and remain like that, then leave stainless bare.
incidentally, the problem with oxygen means that you should never use stainless in wood that might become wet, or indeed in grp below the water surface