Brass In A Marine Environment!

[Zagato]

I thought I read somewhere brass wasn't a good metal to use in or near salt water, yet some Drascombe boats have a keel band made of brass and I think a brass backing plate for the bow eye bolts to tap into. Some use bronze for the keel band!

 

[LittleSister]

Brass in your pocket is certainly useful near salt water!

 

[Tranona]

Brass can dezincification in salt water, but a keel band is not structural and in practice lasts quite well, particularly if the boat is not kept afloat. The backing pad is not in salt water so should also be OK.

 

[Norman_E]

I would prefer any underwater metal that is non structural to be lower down the galvanic scale than my propeller, so from that viewpoint brass looks acceptable.

 

[VicS]

I would prefer any underwater metal that is non structural to be lower down the galvanic scale than my propeller, so from that viewpoint brass looks acceptable.

Or do you mean higher? The keel band is not likely to be bonded to the propeller anyway.

 

[KristiferColumbus]

Brass was invented for decorative ornaments any other use on a boat is asking for trouble.

 

[vyv_cox]

The reality is that some brass skin fittings and ball valves survive for remarkably long times in seawater. One of my ball valves, and possibly the parts connected to it, are undoubtedly brass and are perhaps original to the boat, almost 30 years old. Others, well documented on these pages and others, last five years or maybe less. It's the uncertainty that is the root of the problem but for a keel band it seems a suitable balance of cost against life.

 

[Norman_E]

Or do you mean higher? The keel band is not likely to be bonded to the propeller anyway.

I always think of it as lower, for example from your chart brass might be -0.3 or -0.4 volts against my nickel aluminium bronze propeller at about -0.2 volts.

 

[Zagato]

Thanks folks good to hear.

I'm finally picking up my new boat tomorrow after 3 sleepless nights of unnecessary worry about things like brass keel bands I'm knackered and running on adrenalin with excitement, so silly especially when it's just a little Drascombe. Boats eh! BUT this will be my last!!

 

[LittleSister]

The thin brass keel band on my wooden dinghy was absolutely fine after something like 35 years.