Join Date: Feb 2005
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Re: Props for Saildrive, Stainless vs. Bronze
Thanks for the reply. The Autostream is obviuosly the all stainless prop I refer to. I was completely in agreement with the simplify the metal combo submerged in salt water theory initally. The issue is that it appears Volvo is using the prop as a second line of defense against galvanic action in the whole engine/drive system. Replacing a prop hub every 4-5 years as the spline corrodes away is cheap relative to a drive leg. I replaced the hub on my prop 2 years ago and the spline insert is already showing a good amount of pitting. My theory is they use decay of the spline insert as a 2nd line of defense for those who don't replace zincs twice a year. I sail a Tartan 3700 in New Jersey and even a short haul to replace the zincs is fairly expensive. Most divers don't know when the Volvo zincs are bad, so if you use one you just have them replace it regardless.
But that brings up another issue about factory specs for replacement and how a diver can't possibly meet those requirements as there are locktite and torque specs for installing the zincs. My engine and drive were under warrenty until this season so all work had to be certifiable if you needed to file a claim.
I had a discussion with the folks at Tartan today, they promised to look into it and get back to me. Anyhow, I'm now thinking along the lines of a bronze prop, but one that you can replace the spline. Don't know if that even exists, but I will do some research.
Back a few years ago I had a C&C 35 mk111 and installed an Autostream 3 blade feathering prop on it and I was extremely happy with the performance enhancement it provided. That's one reason i was leaning that way initially now.
Like I said previously, the tought that the thing may become what's in effect a $3000.00 zinc enhancement is what I have issue with. Evaluating the performance benefits against replacement costs every few years has to be considered in making a change.