bent wooden mast

Hi

I have a wooden mast on my M16 scow that is bent somewhat. About 2/3s of the way up it bends towads the rear of the boat. The mast is I think Sitka spruce and is composed of 4 sections glued together. Can I just clamp it to a very stiff staight object like an I-beam and gradually tighten it over a few weeks or months? Not sure this is the right forum but you guys seem to know what your are on about.
Thanks for any suggestions

Simon

[MikeJohns]

I don't know what an m16 scow is. But how does the mast look when unstepped. ie is the kink due to riging loads.

If its still bent when all the rigging loads are removed then you are out of luck. Once laminated timber masts get a set they are in my experience impossible to straighten.

[PAR]

Some sticks are intended to have a pre-bend in them when un-loaded, though I think your issue is related to one to many turns on the adjuster, uppers to tight for too long or just worn out. What ever caused the set is unimportant now.

You'd be surprised how many bent masts get unbent after they are rigged and tensioned properly. Since this is a scow and likely raced, it's time for a new pole if you'd like to remain competitive. If your goals are more daysailing and having fun on the lake, then tune the bend out of the stick during setup. Watch the tension loads, don't over do it. Buy a good tension scale and set it up right. West Marine has an inexpensive one.

Mast building isn't hard and can produce work you can be proud to show off. Have a go at it if you think you're up to it. You could build her the way it was, as the class requirements allow, birds mouth or with a few other methods available. I have a refined birds mouth technique that produces a fine stick, very strong and light weight. We have a scow club down at the local sailing school and I could get dimensions for a new M-16 stick pretty easy and find out what the regs permit . . .


Good Luck,

[Ilan Voyager]

I agree with Mike and PAR. It's very sad, but you have to rebuild a mast if you want a straight and reliable mast. It's not hard to do (just care) and very rewarding.

The bending of the mast is maybe a deformation from a permanent stress -I do not know the word in english (french: fluage)- or worst a beginning of crushing of the wood cells by compression stresses after a hard life of regattas...

Wood mast do no like to stay in compression, and it's good practice to release the tension of the rigging when the boat is not sailing. A permanent stress as little as 10 % of the maximal admissible stress of the specie of wood may provoke a deformation. (look at some roofs, curved down by the weight of the tiling after a few years)

[ready-about]

Simon,

I have an M16 that has a wooden mast also. It is not bent as you describe and I don't recall any M16's with a bent rig. I suspect that the bend occurred due to warpage when the mast was being stored somewhere. If you are going to try to take the bend out of then you need to get the wood thoroughly moist before you put it into the straightening jig. Try wrapping it in some towels and keeping the towels wet for afew days before you put it in the jig. Keep the towels wet for afew days in the jig. Then let it dry before you release it.

It may be easier to build a new mast as has been pointed out. However I don't know where to get plans for one. M16's switched to aluminuim in about 30 years ago. Here in the mid-west used M16's go across the market fairly often. You may be able to pick up a used mast. Check out the ILYA member yatch club links from www.ilya.org Each yatch club often has a for sail page. Sometime in the last 5 years the M16 scantlings changed to require a fixed (non-rotating) mast. A fixed mast will not fit on your mast step. The fixed mast boats also have only one large rudder so they are easy to spot. Any of the older, rotating masts should fit your boat.

[Ssor]

First off the bend will change the shape of your sails.
I have seen telephone poles bent because of unbalanced loads. You might be able to pull it back into shape but I would start planning to build a new one. Check on the Wooden boat forum. There was a discussion there the other day about building a tapered mast with a straight aft line and all of the taper on the sides and front. If the luff is straight then cutting and setting the sail is more predictable.