Tabernacle Concerns

[jplevens215]

Hi All

I am new to this forum and have recently acquired a 1973 Daysailer II. In cleaning and setting up, I noticed something about where the base of the tabernacle and casting meets the lower part of the mast. There is some give and play here, and it looks like the casting was bonded to the lower part of the mast with a goopy adhesive that is no longer affective.

I can raise lower part of the tabernacle from the base of the mast about 1/4" - 1/2". Should I be concerned about this? How does this affect the stability of the mast when sails are raised? I guess I am imagining my mast flying off of the base in a gust, but wanted to ask if my concerns are valid.

Are there suggestions on how to better secure the casting to the lower part of the mast?

I will attempt to add photos. (fingers crossed)

side view

mast step 1.jpg (33.14 KiB) Viewed 6108 times

[GreenLake]

When sailing, the load is almost entirely compression, which is unaffected by your problem. When raising the mast, there's a bit of shear load, perhaps even a bit of upward pull. If unsure, you could try to clean out the "goop" and replace it by something better.

There must be some inner sleeve or spacer that keeps the tabernacle centered? Otherwise it would have slid off already, if things are that loose. Whatever it is that keeps things aligned is making it work while you sail, because as long as things are aligned, they will withstand the compression loads. There is a prominent set of rivets that look like they are holding the base of the mast on the tabernacle, but perhaps they go into slots instead of holes, allowing a bit of play.

That's all I can glean from your pictures.

[jplevens215]

Thanks for the advice Green Lake. That makes perfect sense about the compression load. This is my first season of actually owning a sailboat, so I'll probably be more naive at first about the engineering and mechanics of the boat's construction.

I'll continue to search around on the forum for tabernackle related posts.

[Alan]

mast hinge 2.jpg (185.19 KiB) Viewed 6096 times

mast hinge 1.jpg (136 KiB) Viewed 6096 times

mast hinge 3.jpg (233.62 KiB) Viewed 6096 times

GreenLake is right; there is a sleeve on each side of the tabernacle/aka mast hinge. It looks to me like a previous owner tried to rivet the sleeves to the mast but missed with the rivets, said the heck with it, and gooped the sleeves in. (Or ran out of time before a sail and had to use desperate measures; that's happened to me more than once. )

My mast hinges are attached with machine screws (bottom photo). That allows you to remove the sleeve from the mast if it the hinge gets bent somehow, or if the screws/nuts that attach the sleeve to the hinge plate need to be tightened.

I'd recommend some sort of attachment of the sleeve to the mast, if only because then the hinge won't be falling out of the mast when you're trying to raise it.

New hinge and sleeve parts can be purchased from Dwyer Mast (assuming you have a Dwyer mast to begin with).

[jeadstx]

I got a new mast hinge from D&R (for my Rhodes 19) and the instructions said to drill and tap the flamge for the bolts that came with the hinge assembly. They area larger than the screws used in the old hinge, as I recall they are 1/4-20 thread. Previous owner my have stripped the screw threads and riveted instead of re-tapping and going to a larger screw.

John

[Alan]

1/4-20 screws are what I have, both attaching the sleeve to the mast and stub, and attaching the plates to the sleeves.

Replacing the screws with rivets would explain why there's some play, at least if the rivets are a smaller diameter than 1/4 inch. I was wondering about that - on closer inspection, it looks like the rivets should be going through the sleeves.

[njsurfboat]

Use aluminum rivets for the mast to tabernacle attachment. Drill holes for them to line up. Then, when or if the the boat gets disaster, the rivets fail, and you don't mangle the bottom of the mast.