bronze fittings in a steel hull

[Sailorman59]

I own a 35 foot steel hull sailboat and want to install a bronze through hull fitting, would this be problematic?

[barnakiel]

Dissimilar metals. Salt water.

Can you weld a standpipe?

Or use a marelon fitting?

Etc?

b.

[sy_gilana]

Not a good idea, but, it is possible. There must be no contact between the Bronze and the Steel, and there must be an anode connected to the bronze directly.

[Sailmonkey]

What sort of fitting are we talking about? Are there other options? If you may go forward with this, at least place an anode right next to the fitting.


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[topmast]

Any scrap yard around here has barrels of SS nipples and SS ball valves at $1 a pound .just weld in a threaded nipple or stand pipe. Suitable backing plate may be needed to beef up the hull skin

[Stumble]

I am not sure why you wouldn't just use steel thru hulls on a steel hull. It's easy enough to weld them in place.

[reed1v]

Originally Posted by Stumble

I am not sure why you wouldn't just use steel thru hulls on a steel hull. It's easy enough to weld them in place.

Yeah, why do anything else. Even your chainplates should be welded steel. Much stronger.

[tkeithlu]

I have a steel hull with two bronze seacocks. Originally I isolated them with wood, but that turned out to be a problem in its own right. Now they make bronze/steel electrical contact, although I do bed them in 5200. I've had no corrosion problems at all, BUT my 44 foot boat has 14 large aluminum plate anodes plus a zinc on the prop shaft, and NOTHING, not even bare steel, rusts below the waterline. Keep your water/hull voltage above 1 volt (buy a corrosion test electrode if you don't have one) and you should not have a problem. My boat yard guru said I had taken corrosion isolation too seriously with the wood isolation and that some contact is fine as long as there are lots of anodes around. I pull the anodes every year, wire brush them, and put them back.

[tkeithlu]

"Just weld" stainless steel to common steel is a challenge. I'm sure the pros can do it; at my skill level it takes one pass of the very expensive appropriate wire on the common steel, one pass on the stainless, and then one pass to join them. Then the weld, in this case, must be watertight. This is not a job for an amateur welder like me, nor one I'd like to attempt in a cramped space.

[Cadence]

I might silver solder a wire between the hull and the through hull. That may stop you from creation a battery. JMHO

[conachair]

Originally Posted by Sailorman59

I own a 35 foot steel hull sailboat and want to install a bronze through hull fitting, would this be problematic?

Which hull fitting?

I have blakes seacocks on my steel hull, no bit plastic sheet sandwiched between the mating surfaces works fine to keep them and the hull electrically isolated.

http://www.blakes-lavac-taylors.co.u...s_seacocks.htm

If you weld something in there as others have suggested how do you get it out for maintenance?

[sy_gilana]

The correct way of through hulls on a steel boat is to weld a flange to the hull on the inside, and end weld a stainless tube into both, then the inner end is machined in situ. Seacocks are bolted to the flange, or, the flange is threaded from the inside.

[TeddyDiver]

Of course you can use bronze. Thou they must be galvanically isolated but so should stainless seacocks too..

[Mauro47]

I welded a steel 1/2 nipple directly on the shell (inside ), used stainless ball valves and seal vith epoxy paint the inner surface of the nipple, all the way up to the valve. 31 years in the water and counting.

[Mithril Bham]

Use Marelon