Don, If memory serves me correctly - the M15 centerboard weighs 40 lbs. I believe the original board was a fiberglass - lead sheet - fiberglass sandwich construction. Randy G. On Mon, Feb 3, 2025 at 8:06 PM <donkuehne@hotmail.com> wrote:
You guys are awesome. I am appreciating all the ideas.
Anyone know how much the thing is supposed to weigh?
I am a civil engineer by schooling so I can understand most of the goals and your suggestions of the board and it's fabrication, so keep them coming.
Would still love to discover the actual dimensions. ... but as you all suggested, I can sketch and measure from the trunk something close- likely mocking up some model out of scrap. And then getting creative from there ...
On Feb 3, 2025 12:07 PM, casioqv@usermail.com wrote:
I wanted to throw out one centerboard replacement idea I came up with a decade ago, before I ended up eventually finding a fiberglass/lead board for my M15:
You could build the board from layers of thinner cutting board style HDPE sheets you can get cheap from any plastics supplier, bolted and/or epoxied together with the bolts flush/recessed. This would allow you to cut out a spot for regular lead scuba diving weights in the middle layer, and could exactly match the designed factory board weight and dimensions. You could also easily shape this into a proper foil with just a belt sander. G/flex epoxy with flame treating bonds HDPE well, it be worked with regular woodworking tools, and a lead/HDPE board will last forever underwater.
HDPE has a bad reputation for failure on the rudder in M boats during heavy weather, but I think the forces on the centerboard are much less concentrated, as it is much lower aspect than the rudder.
Also, there are good photos out there of the factory M15 board removed from the boat, that you could trace to get an almost perfect outline, and then scale properly by getting someone to actually measure the length of their board from underneath.
Sincerely, Tyler Backman
----- Original Message ----- From: "jerry montgomery" <jmbn1@outlook.com> To: "Lawrence Winiarski" <lawrence_winiarski@yahoo.com>, "For and about Montgomery Sailboats" <montgomery_boats@mailman.xmission.com> Sent: Monday, February 3, 2025 11:47:46 AM Subject: M_Boats: Re: New to email list, looking for a replacement centerboard
Yes, an iron board could be done from a wood pattern, but it would be pretty heavy, which wouldn't hurt performance except in a drifter, but you'd need to come up with a better way to lift it, like a winch and a wire.
If this is done, the wood pattern needs to be a bit larger to account for the shrinkage of the iron. Seems like it's about 3 or 4 %, but check with the foundry. ________________________________ From: Lawrence Winiarski <lawrence_winiarski@yahoo.com> Sent: Sunday, February 2, 2025 2:22 PM To: montgomery_boats@mailman.xmission.com < montgomery_boats@mailman.xmission.com>; jerry montgomery < jmbn1@outlook.com> Subject: Re: M_Boats: Re: New to email list, looking for a replacement centerboard
You got me thinking about the idea of a cast iron centerboard.....Any other thoughts about this? Would someone commercially be able to cast this from a wood plug better, or just make a wax version better?
On Friday, January 31, 2025 at 03:44:22 PM PST, jerry montgomery < jmbn1@outlook.com> wrote:
Woops! I think Lawrence is right; do a good look for it.
If all fails, I think you could make a decent on out of aluminum plate. Double check this but I think the boards were 1 1/4". I don't think an accurate drawing of the board exists anymore, but you could determine the size by taking some close measurements of the trunk, using a yardstick.
If you're a woodworker you could make one of wood, with a lead slug at the tip, then heavily glassing it, and bushing the pivot hole. Err on the side of too thin because you can always use bushings on both sides at the pivot.
Another good way would be to make a pattern of wood, then have it cast in iron.
Good luck!
________________________________ From: Lawrence Winiarski via montgomery_boats < montgomery_boats@mailman.xmission.com> Sent: Friday, January 31, 2025 3:05 PM To: montgomery_boats@mailman.xmission.com < montgomery_boats@mailman.xmission.com> Cc: Lawrence Winiarski <lawrence_winiarski@yahoo.com> Subject: M_Boats: Re: New to email list, looking for a replacement centerboard
Sounds bad. Dumb question: What about the rope that you use to raise and lower it? Did that suddenly come loose too?
If it was me, I'd exhaust all methods to find it at the bottom first. Spirit lake is deep, but not that deep. Maybe try and recover it. Google says around 40'.
On Friday, January 31, 2025 at 12:23:50 PM PST, Don Kuehne < donkuehne@hotmail.com> wrote:
Hello,
I am the proud owner of a M15 on Spirit Lake, ID.
It can get pretty gusty here and my "Penelope" can get rocked on the dock pretty aggressively.
The centerboard front pin had worked its way loose (unknown at the time to me) and during a sail last season I notice a bump... then no centerboard.
My board is lost in the deep and I am looking for a replacement. Does anyone know of a source or specs for the size, shape etc... To have a new one made?
-Don