Repair of broken mast

[Memphis]

I broke my mast off today at the tabernacle(above deck). It tore about 5/8 to 3/4" of mast just above the top part of the tabernacle. The mast step casting of the tabernacle was only about 3/4" tall(going inside the bottom of the mast).

Can I just saw the bottom of the mast off and reinstall the tabernacle? If I remove 3/4" of the mast and raise the lower halyard sheaves will it cause other problems?

[TIM WEBB]

Not sure I wanna know how you broke it (been there, done that, got the T-shirt!), but the first thing to do is determine whether or not you bent the mast. If you did, you might first want to determine if you can straighten it. If you can't, you might want to go mast shopping. If you can, or it's not bent, you can shave a bit off the bottom no prob, although your boom will ride a little lower, unless you have enough wiggle room to raise the boom downhaul cleat a bit without having the halyard bottom out (top out?) in the masthead sheave. Not sure what you mean by "raise the lower halyard sheaves"?

[Memphis]

Doggoneit! I forgot that the boom would end up lower.

What I should have said, instead of "raise the lower halyard sheaves", was move the halyard blocks up/higher on the mast. They are positioned right at the bottom of the mast.

Thanks for your input!

[algonquin]

If you mast is still useable you could consider trimming your mast and remounting the tabernacle. Then replace the short mast section that goes below the tabernacle to the sole with a longer one or possibly shimming the mast base. Brad

[K.C. Walker]

Cutting your mast three quarters of an inch is pretty inconsequential. You won't even notice that your boom is three quarters of an inch lower. Besides moving your cheek blocks up on the mast the other problem could possibly be shroud length. If you're turnbuckles or adjustors run out of room you can then deal with that. I trimmed my mast stub by a total of 1 inches. I have a piece of Ipe lumber under the mast base on top of the keelson which has worked fine for a couple of seasons and I expect will last for quite a long time.

[Memphis]

Thank you for your help. The mast looks fine, so I will take the plunge and cut off a small amount. Then I'll move the cheek blocks up(thanks for giving me the correct term). Unfortunately, the shrouds will have to be moved up the mast as well, since the turnbuckles already tighten near their end. As Tim Webb suggested I think I can move the downhaul cleat.

I am concerned about the number of holes in the cast part of the tabernacle. The bottom cast looks okay with 3 holes, but the top one has 9 holes in it, perhaps from previous repairs. Do you guys have any thoughts about the strength of the cast with so many holes?


Since both Algonquin and K.C. Walker mentioned extending or replacing the portion of the mast below the tabernacle, I'm wondering how involved it would be to add a "shim" at the keelson. Can you briefly describe that task?

[K.C. Walker]

I think a new cast mast base would be a good idea. They are reasonably priced from D&R. The strength is not the problem, that should be fine. The problem will be lining up your new holes with old holes. If you start fresh with a cleanly cut off mast and a new cast piece you should be able to get a much better fit for your screws. Be very careful drilling these holes. The soft aluminum in the mast and the harder casting and the odd shape make it difficult to drill the holes accurately. It really helped me to use machinist drill centers to get the holes started.

My shim under the mast base on the keelson is the width of the keelson and about 12 inches long. It's made of Ipe which is a very dense rot resistant tropical hardwood that's used in decking. I just used 4 stainless screws to hold it to the fiberglass keelson. The force is all straight down so you really don't need anything more than to keep it from shifting around.

Just guessing, but I'll bet this is not the 1st time your mast has been cut off. With the multiple holes in the casting and your turnbuckles close to bottoming out, I think the evidence points in that direction. But, don't worry, I've read previously that a former national champion had a mast that was significantly shorter than standard.

Your boom in relation to your masthead will not change so you don't have to worry about your downhaul cleat. Your boom will be a little lower but the DaySailer was designed with a high boom, so no problems. Or if you put the shim under the mast base everything is going to be in the same place, except the tabernacle.

[Memphis]

Thanks so much, KC.