Need help finding a (very) limited clearance anode.

[macmanmike]

My new/old boat - '81 Alberg 29 - does not have an anode installed. Everything from the engine to the prop was new in 2007. I want to keep it that way There is limited space between the stern tube and propellor (3/4") and the lock washer/castle nut (1 1/2") to the end of the shaft. I cannot find a "doughnut" or prop nut anode (needs to be Magnesium as I'm in fresh water) that will fit. Does anyone know of a source for VERY limited clearance anodes? Maybe a custom made anode? I'm aware of the "Grouper", but would rather not. Thanks.

[S/V Alchemy]

You need a "propnut anode", and here's where to get a magnesium one.

Martyr Anodes ? Zinc, Aluminum, Magnesium Anodes for Pleasurecraft and Commercial Craft

The alternative would be a rudder or a hull plate anode (studs or bolt-through) bonded to the shaft, which I recall is a brush-type thingie.

[Kijit]

I have a similar problem with a zinc on my rudder post. I buy one of the limited clearance zincs and then have a local machine shop cut it down until it fits. Not the cheapest solution, but cheaper than a new shaft.

Gerhard

[macmanmike]

@ S/V Alchemy - the problem is the shortest prop anode I can find is 3". I only have 1 1/2" from the back edge of the prop to the end of the shaft. I'm familiar with Martyr and have requested a quote on a custom anode.

@ Kijit- I have considered yor suggestion. What is it costing you to have it cut down.

Thanks to both for your help.

[Kijit]

I use a collar zinc with a center hole of 55 mm, but I don't know the length as I don't have one handy. I have it cut down to a length of 22 mm which is basically just wider than the width needed for the screws to keep it together. It typically costs about $30 to have the shop do it. I have a friend that had a "hobby" machine shop at his house and he did the first one for free....then he moved!

Gerhard

[AnchorageGuy]

You may need to have a zinc installed on the outside of the hull with a brush type attachment on the inside prop shaft if you can't get a propnut zinc to fit. Chuck