Anyone Successfully "Marinised" an Edson Aluminium Bilge Pump?

[Andrew Troup]

I've been a big fan of these ever since a trip across the Pacific long ago where we hand-pumped up to 20 tonnes of water a day out of the bilge without undue hardship. (400-500 strokes every two hours, night and day). The reason why is another story.

I'm looking to get an Edson and would prefer to have it a permanent fixture, but from what I've seen, only the bronze ones will stand up to sitting for long periods with salt water residues.
Bronze is not a desirable option for an alu hull. So with an alu pump, seems to me it's either pack it away, shrink wrapped for emergency use, or strip it and give it a really durable alodine conversion treatment + high tech paint job. (or something more exotic: Nikasil? Hardkote? Nyalic? Inversalu? Metabis?)

Q1: Anyone tried anything along these lines?

Q2: Does anybody know for sure: Do recent Edson alu pumps have a different surface treatment regime than the ones they made 20 years ago?

[David M]

I have quite a few bronze fittings in an aluminum hull. There are plenty of methods of isolating the bronze from the aluminum. I have never found any coating that sticks to aluminum in a salt water environment for more than a few years. It all eventually starts blistering.

Isolation might be a better solution than a coating.

[gjordan]

Andrew, would it be too hard to mount it (the bronze one) in a conventional manner, but with good insulation? Maybe a 3/4" piece of some non conductive material and use SS or titanium bolts with insulating sleeves and washers? I think the Edson is the Cats Meow for any cruising boat. It is like having good ground tackle, expensive up front, but the best insurance your boat can have. ____My 2 cents worth._____Grant.

[Andrew Troup]

Thanks for the replies, I appreciate you both taking the trouble.

I'll give it some more thought - insulation is certainly an option, but I remain uneasy about the possibility for some external agent (which could be as innocuous and insidious as a trail of damp salt) to create a conductive bridge across the insulation.

I don't want to feel I have to continually patrol the boat for instances of "the enemy within", if I can possibly avoid it; sometimes in the lifetime of a vessel it may be left unattended for periods...

In the interests of 'rot' prevention to the hull and structure, I'd rather avoid than mitigate.

[Bash]

I take it you're talking about the manual pump. If this is the case, it does not need to be mounted on the hull. The only thing that actually needs to touch the bilge is the pick-up strainer. The pump itself can be mounted to a block of marine ply that has been bonded to aluminum.

[Andrew Troup]

Bump ...