Wooden Mast Partners

[allene]

My mast is 1 inch off to starboard so it sure does happen. I am told that it happens because someone measures 37 inches and says, OK, cut at 1/2 inch off of 18 inches and gets the 1/2 inch the wrong way.

In any event, my mas partners are fairly tight which I have been told is wrong. I have been told that they should not be tight so that the mast can move with expansion without being restricted. A small amount of space isn't going to prevent the partners from supporting the mast. My mast is spruce.

I would suggest you get this point clarified before making the partners and wedging them in as I did. That said, I have seen no ill effects from the say I have it so I have not changed it.

By the way, after 20 years of trying everything out there, the best way to seal the mast off is with high quality duct tape covered over with sumbrella to keep the sun off it. Nothing else worked on my square cross section mast.

Allen

[Ian McColgin]

Duct tape makes sunbrella redundant at best and can, if you're unlucky, cause the condensation that leads to rot at the partners. It's dirt simple to make a proper canvass mast boot.

[allene]

Originally Posted by Ian McColgin

Duct tape makes sunbrella redundant at best and can, if you're unlucky, cause the condensation that leads to rot at the partners. It's dirt simple to make a proper canvass mast boot.

It is not simple to get anything to seal against a square mast and having had rain water rot my mast step, I think keeping the rain out is very important. The problem is that the canvas mast boot will not seal on the flat sections and rain water will just run down to the mast step.

I am not understanding the condensation issue. If you have something that is water proof, how can it differ from another method that is water proof. Is that expensive silicon self adhesive tape, that doesn't keep the rain out going to be better for condensation than cheap duct tape?

I probably should have clarified that I formed a tapered boot out of sheet plastic then duct taped over that so there was only 1/2 inch or so of tape on the mast and that was about 5 inches off the cabin top. The tape did not contact the partners. I covered the plastic with tape then covered all of that with sumbrella which was keeping the sun off the tape. The tape degrades rapidly in the sun so the sumbrella is not redundant.

[Brion Toss]

[quote=allene;6099
In any event, my mas partners are fairly tight which I have been told is wrong. I have been told that they should not be tight so that the mast can move with expansion without being restricted. A small amount of space isn't going to prevent the partners from supporting the mast. My mast is spruce.
Allen[/QUOTE]

The partners don't support the mast; the mast, wedged, should be unified with the partners, in order to create an effective couple with the step. If it isn't, what you have is, to some degree, a deck-stepped-keel-stepped mast, which is to say one that might be 40% or so more limber than it could be. So you either need a heavier mast -- which is the case for actual deck-stepped masts -- or you have one that won't hold its shape.
Fair leads,
Brion Toss

[allene]

Originally Posted by Brion Toss

The partners don't support the mast; the mast, wedged, should be unified with the partners, in order to create an effective couple with the step. If it isn't, what you have is, to some degree, a deck-stepped-keel-stepped mast, which is to say one that might be 40% or so more limber than it could be. So you either need a heavier mast -- which is the case for actual deck-stepped masts -- or you have one that won't hold its shape.
Fair leads,
Brion Toss

So you are saying that what I have is correct in that the partners are snug with the mast and that what I was told is wrong?

[Ian McColgin]

To clarify terminology, partners refers to the whole structure of bracing around the deck or coachroof hole the mast goes through, collar, wedges and all. The hole needs to be large enough to get the mast in and out easily. The mast is then wedged nice and snug. As Brion explained, a keel stepped mast can be of lighter sections because it's held in two places.

On the boot, there are overpriced rubber boots that are nice for plastic boats with tin sticks. It's acutally easier to make a boot for a square or rectangular section mast - just four pieces - than for a round section that really works best with a six piece boot. That's the basic pieces, not counting a top and bottom bands.

G'luck

[allene]

Originally Posted by Ian McColgin

To clarify terminology, partners refers to the whole structure of bracing around the deck or coachroof hole the mast goes through, collar, wedges and all. The hole needs to be large enough to get the mast in and out easily. The mast is then wedged nice and snug. As Brion explained, a keel stepped mast can be of lighter sections because it's held in two places.

On the boot, there are overpriced rubber boots that are nice for plastic boats with tin sticks. It's acutally easier to make a boot for a square or rectangular section mast - just four pieces - than for a round section that really works best with a six piece boot. That's the basic pieces, not counting a top and bottom bands.

G'luck

OK, I found a nice picture showing what you said.


As for the boot, I agree that it is easy to make a boot for a square mast but I still assert it is more difficult to make one that keeps the rain out just because there is not a natural tension holding the sides tight against the mast. With a round mast, there is equal force all around the mast. With a square one, there is only tension at the corners. In other words, you can easily pinch the center edge of a square boot and pull it away from the mast. My bronze ring is rectangular as well, which doesn't help. The picture below still used some of that fancy self adhering silicon tape which I used before turning to duct tape in desperation. It leaked.

[Ian McColgin]

Especially for square section, I use a little "Shoe Goo" or their marine variation since it can be gotten off after a decade or so if the cloth wears out.

I have the boot inverted pointed up a bit higher than it will actually go - pays to practice and mark before any gooing. Pick up a bit of the edge against the mast and squeeze a bead of goo all the way around. Then start frapping from above (on the mast) the goo bead down so your squeeze out will be inside. Once that's completed, fold the bood down and into place to frap around the collar. The goo bead will keep the water from running in on the flats. Even on a round mast it's nice because with the boot folded down you have a cloth ring that tends to hold rain water against the mast and let it dribble unless sealed. Once running down the outside, it will be fine. Modern fabrics might be treated with silicon but natural cotton will swell.

G'luck

[benz]

I made my boot like yours, Allen, only with 2" vinyl pipe wrap tape rather than duct. Being plain black, I didn't need to cover it for looks, and it held up well to two years of tropical sun. And it never leaked a drop. But my boat has the advantage of a small, special-built coaming around the partners, which the boot goes to the outside of, which helps a lot. It would be easy enough to fabricate one with G-10 and epoxy.
Ben