Tabernacle question from a newbie

Moderator: GreenLake

Tabernacle question from a newbie

Postby RobH912 » Thu May 23, 2019 3:18 pm

Hi just posted an introduction in the DS I section on my new boat and have a question regarding the tabernacle set up that my boat has.

Did some searches and didn't see an answer.

My boat came with a tabernacle setup for the mast which for me was a positive feature. I've read the pros / cons.

The question I have is the lower section of the mast is not connected at all to the boat, so I was told by the previous owner that even with the tabernacle it will take two people to step the mast because as you are raising the top of the mast, the bottom also lifts off / out of place. Seems to defeat the purpose of having a tabernacle.

Rather than having an open bottom on the mast to fit on top a mast step casing, the bottom of the mast has a tenon shape sticking out made of hard plastic which fits into a "metal tray" where the mast rests.

The metal tray has side holes and there are pins / bolts going through the tray which prevent the foot of the mast to move back or forward.

To secure the bottom of the mast to the tray can I simply drill an appropriate sized hole through the mast tenon, step the bottom of the mast and secure with a clevis pin / cotter pin set up?

Pictures are worth a thousand words.

Thanks for any thoughts.
Rob
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RobH912
 
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Re: Tabernacle question from a newbie

Postby GreenLake » Thu May 23, 2019 3:45 pm

Make a plywood disk with a hole that fits the mast profile exactly, and attach it to the lower mast portion with a hose clamp (so it rests against the deck - the hose clamp would be wide enough to not slip through the hole). That should prevent the lower portion from rising while the mast is stepped.

Alternatively, similar disk, but drill a hole in the mast support just below the deck to insert a pin that keeps the disk resting under the deck. Same effect. Just make sure that you size the pin to be strong enough to hold your weight in shear (because if you step on the deck, your weight would rest on it).

Does that help?
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Re: Tabernacle question from a newbie

Postby RobH912 » Fri May 24, 2019 1:02 pm

GreenLake thanks for the quick reply.

I can sort of visualize the plywood collar (for lack of a better word) around the top of the mast butt and held in place top & bottom by hose clamps around the mast, the collar up against the cuddy cabin ceiling. This would prevent the mast butt from lifting off of the mast step which is the goal.

Not very handy with wood, I am a better with mechanical things, and don't own the tools needed to cut out the mast silhouette from piece of heavy plywood ("fits the mast profile exactly").

Maybe a dense foam or heavy styrofoam collar? Could think about ways to attach the collar for the season.

You didn't comment on my thoughts on trying to pin the mast butt to the mast step. Not strong enough?

There seem to be a lot of boats with a tabernacle mast step set up out there, including one version of the Cape Cod Shipbuilding DS1s. Anyone know if they are set up with the mast butt fixed to the mast step, or utilize some sort of collar?

Cape Cod Shipbuilding is not very far from me and maybe I'll give them a call after the long weekend to see what they do.

Thanks!

Rob

Cape Cod
Eastham, MA
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Re: Tabernacle question from a newbie

Postby GreenLake » Fri May 24, 2019 1:13 pm

Sure you can also use a pin. After all, the rails have the requisite holes.

The strength requirement is moderate. Effectively equal to the force that you use to push the mast vertical.

This is much less then the compression force from a tight rig - so if you use a pin you need to make sure that it doesn't carry any of that weight; that is, it doesn''t prevent the mast step from taking the load.

Possibly easier than a collar (although, depending on geometry, you might find that a simple hose clamp, by itself, is enough). I had suggested the collar to be tight, so that a hose clamp cannot slip past, but if the deck opening is also good and tight, that may not be necessary.
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Re: Tabernacle question from a newbie

Postby GreenLake » Fri May 24, 2019 1:16 pm

PS: if you were trying to fashion a part like that from wood, a simple coping saw would work to cut along a curve.
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Re: Tabernacle question from a newbie

Postby RobH912 » Fri May 24, 2019 2:26 pm

GreenLake wrote:
The strength requirement is moderate. Effectively equal to the force that you use to push the mast vertical.

This is much less then the compression force from a tight rig - so if you use a pin you need to make sure that it doesn't carry any of that weight; that is, it doesn''t prevent the mast step from taking the load.


I was also thinking about making sure that the pin does not carry any weight and thought that the best way to do that would be to attach the shrouds, have two people step the mast, get the forestay attached, get the tabernacle pin in, make sure that the shrouds & stay are all tight, the mast under compression, and then mark the drill spots on the tenon shape on the bottom of the mast through the "correct" hole in the rail. Unstep the mast, take the mast butt to the garage, then drill the hole.

Your comment on maybe just a hose clamp got me thinking maybe just using a piece of an actual garden hose or rubber tubing with the hose clamp running through the hose. That would be simple. WDYT?

Thanks!

Rob

Cape Cod
Eastham, MA
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Re: Tabernacle question from a newbie

Postby GreenLake » Fri May 24, 2019 2:57 pm

Anything to make the mast wider than the deck opening. Your solution sounds great, it gets around the problem with a bare hose clamp resting against the deck in only one spot, and looks like less effort than drilling for a pin.
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Re: Tabernacle question from a newbie

Postby RobH912 » Sun Jun 16, 2019 11:05 pm

Holding the Mast butt in place using a “collar” made from a piece of garden hose and a hose clamp worked great.

Stepped the mast today in the driveway for the first time. The mast butt did not lift at all as I walked the mast up.

The hardest part of this solution was getting into the cuddy cabin to tighten the clamp.

Now that I’ve got that solved, and mast stepped, I can see that I’ve got some more rigging questions which I’ll work on tomorrow.

GreenLake thanks!

Here are a couple of pictures
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Thanks!

Rob

DS1 #14061
DS1 #2444
Cape Cod
Eastham, MA
RobH912
 
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Re: Tabernacle question from a newbie

Postby GreenLake » Tue Jun 18, 2019 3:18 am

Looks great!
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Re: Tabernacle question from a newbie

Postby Signalcharlie » Fri Jun 21, 2019 6:23 pm

Just found the thread, nice work. Our lower mast section is secured just below the cuddy top, like you did. Your question motivated us to finally replace the old hose clamp, it was not marine grade stainless and rusted, came apart one day while lowering mast. The new clamp is marine grade stainless, and it tightens around a rubber spacer to prevent dissimilar metal corrosion.

So our tip is to make sure to use a high quality stainless clamp.

Image

http://smallboatrestoration.blogspot.com/2019/06/1971-oday-day-sailer-ii-cyane-21-jun-19.html
Kent and Skipper
1971 DS II #4624 "CYANE"
Small Boat Restoration blog http://smallboatrestoration.blogspot.com/p/o.html
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Re: Tabernacle question from a newbie

Postby RobH912 » Sat Jun 22, 2019 11:06 pm

Good suggestion on marine grade stainless steel clamp.

Don’t think the clamps I bought on Amazon are, but running through the piece of old garden hose I am hoping that the clamp will last the season. Have 3 more clamps and several feet of hose.
Thanks!

Rob

DS1 #14061
DS1 #2444
Cape Cod
Eastham, MA
RobH912
 
Posts: 60
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Re: Tabernacle question from a newbie

Postby GreenLake » Sun Jun 23, 2019 12:58 am

There's a corrosion protection that you can get in spray form. Builds a film on exposed metal (but not a paint). If you coat one of your standard hose clamps with that, it should last that much longer. Useful stuff to have around. I use it on trailer chains where the zinc coating has rubbed off and other things like that.
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