Reinstalling the Boomkin

I will soon be reinstalling my boomkin on Voyager and noticed when I removed it, the location of the deck bolts had put the two planks of the boomkin in tension. The two fingers of the ‘V’ were being pulled toward each other. Should this tension be present or should the boomkin be simply bolted down where it sits on the deck with no compression? My main concern is this load may break the bonds of boomkin’s outboard assembly.


Did you install the port bumpkin piece to port, etc. If you did, I would plane the ends of the bumpkins until they met without stressing the bumpkin. Unfortunately, you will have to remove the bumpkin.



The boomkin is off the boat and in one piece, although I am considering taking it apart to service and reglue. Lord knows how long it’s been.

So you are saying there should not be tension between the two sticks?

Hi Warren, I replaced the boomkin on Calliste with Teak.

When I removed the origonal one, the two legs were not glued together.

When I replaced them I didn’t glue them either.

IMO the boomkin chain plates act as a gusette plate holding the joining end together with the through bolts.

BCC Xiphias had the glue-jointed boomkin, too, so there may be others.


Voyager is a CBCC and the chainplates are about 5" x 5" and have only four thru-bolts. (If, by chance, anyone has a spare set of SLM chainplates they’d like to sell, please let me know.) Glue, I think, is a necessity.

So, with the SLM method of assembly, no tension between the inboard ends of the boomkin. The thru-deck bolt holes should line up with the boomkin bolt holes.

Thanks everyone.

IDUNA’s two bumpkin pieces are joined at the outer end with two bronze plates. One plate is on top of the bumpkin along with the backstay tang the other is underneath the bumpkin. This assembly is thru-bolted through the two bumpkin pieces and holds the two pieces of lumber, which make up the bumpkin together.

I do not believe I would reley on just glue to join the two pieces of lumber in the bumpkin together.


I agree with Rod – Itchen’s boomkin is through-bolted between plates
top and bottom. I’ll defer to any naval architect engineers in the
forum, but I think that glue would serve very little structural
purpose here. Useful to keep water out of the joint and make a better
looking and paintable surface at the joint, yes indeed but not very
robust structurally.

On Mon, Jan 26, 2009 at 11:48 AM, BCC Forums wrote:
ates. One plate is on top of the bumpkin along with the backstay tang the other is underneath the bumpkin. This assembly is thru-bolted through the two bumpkin pieces and holds the two pieces of lumber, which make up the bumpkin together.
ber in the bumpkin together.
Attachment: boomkin51.jpg 168(kb)


My boomkin is currently removed from the boat; the two pieces are not glued together. I am replacing the stainless steel boomkin plates (original equipment from Sam L. Morse) with bronze plates, which were fabricated by Port Townsend Foundy.

When you make reference to “SLM chainplates”, I assume you are referring to what I call (and are referred to in the BCC Construction Manual) as boomkin plates. If so, I have no further need for the stainless steel ones and you are welcome to them.



I sent a PM in response to your kind offer.



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I am replacing my SS chainplates with bronze, the old ones look okay but I don’t trust 30 year old stainless. I am having Rockport Boat Shop make me some replacements fron silicon bronze plate, they will use the old ones as patterns. I don’t know the cost yet but they could just as easily make two sets if you are interested.

Hi John, are you doing all your plates? Let me know the price when you get it.
See you this summer again?!

Hi Ben,
I am replacing the six side chainplates as well as the stern two chain plates that go to the boomkin, maybe I’ll take on the lower dolphin striker like you did last year as well. I’ve removed most of the chineplate already and plan on finding out the price by next week. I have the galley riped up now too, I think it’s going to be pretty sweet with the new wood stove.

I reinstall my boomkin next weekend and failed to take a measurement of the distance from the transom to the top boomkin plate tang. I received SLM plates and adjusted the angle of the ‘V’ to fit the new plates, so the old holes are no longer useful as a guide. If someone happens to have this obscure distance written down or is within tapemeasure’s reach, I’d appreciate the measurement as a guideline.

Changes to V’ger’s deck layout have been wholesale, and now the fun comes in making it all fit…


I’m looking at the SLM Construction Manual and see 32 7/8" from aft most edge of transom to center of eye fitting on bottom of tang for boomkin stays (measured along centerline). And 20 1/4" from transom to the inboard edge of boomkin (measured along centerline). But I can get to my boat tomorrow for you, and get that exact measurement you are looking for, if you need that.

One issue I think will be the length of your boomkin stays, are you remaking those to fit your new boomkin, or trying to fit your boomkin to those existing stay lengths?


Thanks very much for the info. Gotta get me one of those construction manuals. One thing different about the plates is that the SLM plates move the backstay on my boat back about 1.5". Fortunately there is enough play in the turnbuckle to compensate. I’ll be snipping the length of the boomkin stays, something on the order of 5-6 inches or so. Will wait till I reinstall the boomkin as the math required to calculate off the boat is a bit beyond the reach of my memory.