Fabricating New Mast Wedges

[Ian McColgin]

I've seen plenty of instances of wedges shaking up and out. In all cases this was solved by making more accurate wedges that contacted the partners over almost their whole depth.

Even a steep wedge will lay against the mast flat and provide protection to the mast but if it's only in contact at the upper part of the partners it's just an incline plane that wants to shift the load.

Make a very gentle bevel. As a start, make the wedges way too long so once you get them set you can mark where to cut the bottoms off. Flat bottoms makes getting them out easier as well.

Make the bevels fit. If a round or ovular mast, the inner (female) arc is a bit tighter than the outer. Get these right for good contact. Whether flat or round sided, number or lable the wedges so you can get them in and out without a lot of fooling around.

Personally, I do not like rubbery wedges. They move and they have high friction making them hard to set and harder to extract. Good hardwood wedges properly shaped are the way to go.

Even on glass boats.

I' not against the poured wedges if the parnters are beveled just a little, bottom a sckoch smaller hole than top, so you can set and remove with confidence.

G'luck

[Douglas]

Ahoy Brion ,,, do you stock or order those rubber wedges for mast to partner spaces ?

[asdf777]

I have starboard wedges, installed by a professional rigger, but don't like them. They seem too hard for both mast and deck, and I can feel the mast pushing on deck when the boat is heeling. Softer material like rubber seems like a good suggestion.

[Ian McColgin]

Feel mast pushing on the deck?

Properly made partners handle that stress and part of the idea of a keel stepped mast is that it's held in two places and can be a nudge lighter than a deck stepped mast.

In an older boat, the racking strain can be interesting. My old Goblin, an Alden 43' schooner, was almost 70 and when beating in any sort of wind the main mast cranked the hul and coach house so much that the door between the aft stateroom and the main saloon could not be opened if it was closed and not closed if it was open. The rectange of the door frame became a sort of trapazoid. Made her leak some as well.

If the structure is not handling the load at the partners, then you have some interesting problems possibly with the partners, maybe with the stick itself, and certainly with how you tuned it.

Start with a careful analysis which, if you're not up to it, find a qualified rigger who can.

G'luck

[asdf777]

Hi, not sure how else to put it, but I don't have a good feeling about these starboard wedges - they're just relaying the force exerted by the mast to the deck without absorbing the vibrations. Of course, the opposite side argument is that if the wedges are too soft, the mast is subjected to greater pressures.

BTW, not sure if Brion has a preference, but I know some riggers recommend spartite. It's expensive and not easy to install by yourself, but if properly installed, it's deemed by many to be the ultimate solution.

Best regards,
Gleb

[asdf777]

Another thing to keep in mind is that if there is uneven amount of space between the mast and deck, it's going to be difficult to select wedges to keep the pressure distributed equally while keeping the mast straight.

For example, in my case, there is slightly less space on the port side, and even though the starboard wedges have a big O clamp around them to distribute the pressure, the boat is creaking more on the starboard tack, when the boat is heeling to port.

So anything that can fill in the gap uniformly while providing the necessary density will probably be a better solution. Especially if it can keep the water out. Spartite is supposed to do all of the 3...

What would the argument be against spartite besides cost?

Thanks,
Gleb

[Brion Toss]

Hi there,
Dear Mr. Euler, some years ago, demonstrated the behavior of columns under compression. He probably didn't have sailboat masts in mind, but because of him we know that keel-stepped masts can be a lot lighter -- not just a nudge, Ian -- than deck-stepped ones. For more on this, stand by for an article I'm preparing on rig tune for wooden boats. Meanwhile, I think Ian is otherwise correct; you want the partners to be working with the mast's energy, in order to stiffen it in the lower panel.
Spartite is indeed my favorite wedge material, partly because it is resilient, and won't put localized stresses on the mast, partly because it allows you to put the mast right where you want it, even if the partners are off-center, and partly because it is usually much cheaper than custom wedges to accomplish the same thing. Plus it is fun, kind of like pre-school playtime, as it involves modelling clay, foam, and masking tape, in addition to pouring thick blue liquid.
Fair leads,
Brion Toss