Regarding custom casting, Roger Winiarski at Bristol Bronze (Tiverton, R.I.) has custom-cast, heat-treated, high-strength, high-quality replacement castings for the M17 chainplates. Roger created the bronze plates from a prototype that I crafted: I wanted a thicker cross-section to the triangular piece to which the shroud turnbuckles attach. I "beefed" up the original plate from my '85 M17 by riveting two triangular pieces of aluminum (easy to cut and shape) to either side of the existing triangular piece. Roger's casting is almost identical to my prototype, although imperceptibly smaller because of extremely slight shrinkage of the cooling bronze. Roger has a proprietary high-tensile bronze that, once heat-treated, is indestructible: Give him a call, becauase he loves to tell people about it and you'll learn a little about marine alloys. I believe my new bronze plates are stronger than the original, even though bronze is not quite as strong as stainless, because my plates are one-piece castings (the stainless are two piece welded hardware) and the triangular piece has a thicker cross-section. And, as I say, Roger touts the strength of his heat-treated alloy. Anyway, the new plates have one problem: Roger "cast in" the 1/4" mounting holes and, because of the imperceptible shrinkage, the plates can't be mounted with the original drillings in the M17 cabin-trunk. This wasn't an issue for me, because, given that my boat is an '85, it was about time to epoxy and redrill the existing holes anyway. If anyone is interested in Roger's parts, he has two plates ready to sell which, I imagine, could be obtained quite reasonably. Should Roger receive more than one request, future orders would have to be in bulk, or would have to be grouped with other projects, to defray heat-treating cost (Again, Roger will explain). The Bristol Bronze chainplates would be the perfect accompanyment to any M17 with bronze ports (as they are to my retrofit bronze windows). I mounted my new castings with sheet-stock backing plates and 1/4" bronze machine screws: I'm thrilled with the result. I'll eventually take a good photo of the installed plates (and my window retrofit) for the MSOG site. http://www.bristolbronze.com ----- Original Message ----- From: "Honshells" <chonshell@ia4u.net> To: <montgomery_boats@mailman.xmission.com> Sent: Sunday, February 24, 2002 10:15 PM Subject: M_Boats: Centerboard Doug, Is Navy Brass bronze? If a new CB were to be cut from stock using a CAD file, would the lead and trailing edges have to be shaped, or it the existing board just a flat section of metal? What about having the board cast in a different metal? Would that be prohibitively expensive? Thanks, Craig ----- Original Message ----- From: "Doug King" <msog@msog.org> To: <montgomery_boats@mailman.xmission.com> Sent: Sunday, February 24, 2002 9:38 PM Subject: M_Boats: Centerboard Two suggestions: 1) Go to "Other Resources" -> "Search List Archives" on the MSOG site. Two searches will cover the topic, type the word "galvanize" in the first search term box, and "centerboard" in the second search term box. You'll get several hits. Then, go Back and use "CB" instead of "centerboard" for a second set of messages. There's quite a bit of discussion on this subject, but not sure any consensus was reached. Message six under the second search (galvanized and CB) by Howard Audsley discussed the possibility of getting a CAD file (probably a .dxf) made that could be used to get steel, or Navy Brass or SS if you're rich, boards cut more cheaply. If there's enough interest, maybe it's worth a bunch of people getting together to pay for a CAD file to be used by anyone who needs it. I'd go in on it, and it could be downloaded from the MSOG site. 2) The Potter people talk about having decent results galvanizing their CB, which are steel (Montgomerys are originally cast iron on the older boats, FG later on): "One of the things that has become popular (and standard equipment) on the Potters is a galvanized centerboard. When I had my P-15 I was planning to have the centerboard galvanize dipped when the paint gave out. My board was a slab of steel... Don't know if it can be done with cast iron. Anyway, for what it's worth, the Potter Yachters seem to have good luck with the galvanized boards." Maybe someone who subscribes could write to their listserver and see what works best re: painting galvanized, etc. Unless Bob Eeg, Jerry M., or Judy Blumhorst want to just tell us... ;) Doug At 06:45 PM 2/24/02 -0500, you wrote:
I'm sure this question has been addressed exhaustively in the mailing list archives, but I've never had much success accessing them.
Is it possible to galvanize the older M17's centerboard? If so, has anyone out there done so?
Would galvanization be preferable to epoxy painting? I imagine epoxy painting and filling would be cheaper and would make faering easier.
Would galvanization be prohibitively expensive?
Would galvanization give complete corrosion resistance?
Thanks!
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------------------------------------------ Doug King M-17 #404 "Vixen" Montgomery Sailboats Owners Group Web site: http://msog.org Email: mailto:msog@msog.org