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Milli
04-24-2013, 11:22 AM
Well it's not acutally a repair. I am replacing the mast on my 11 ft sailing dinghy (balanced lug rig with solid wooden mast). A friend gave me a great new mast but it is 2 ft too short (new mast is 10 ft and needs to be 12 ft). The new mast is round and is about 2 inches diameter at the top (there is a dumb sheave for the halyard). I would like to add a section to the mast (assume at the top is best from a stress standpoint?) and not sure best way to do this. I have read a number of posts that suggest a "clothes-pin" scarf for a solid wood mast. It certainly looks like it would work well but I am not sure how to go about cutting it on a 2 inch round mast??? Any suggestions on tools methods?

Alternatively I wonder it there are some easier joints that would work. What I am thinking is to cut the mast at 90 degrees (below the dumb sheave) and then install a vertical wooden dowel to mate the joint with the new upper section (probably 2 1/2 ft long). Everything would be glued up with epoxy. Is this acceptable or are there any other ideas?

For reference this is a Jim Michalak piccup pram with a 70 sq. ft. balanced lug sail.

Thanks

Thorne
04-24-2013, 12:18 PM
I tried something similar twice, and they both broke in strong gusts -- luckily nobody was hurt as I had guests sitting next to the mast both times.

For a stick that size, just break the bank and buy a couple of clear grain Doug Fir 2x4's and epoxy them together. Let cure, shape with power planer or tools of choice, and you've got a new mast. I usually have the glue joint running fore and aft to keep it stiffer, as sideways flexing is better than fore and aft.

http://www.luckhardt.com/newmast0.jpg

http://www.luckhardt.com/newmast3.jpg

http://www.luckhardt.com/masthead1.jpg

Brian Palmer
04-24-2013, 12:33 PM
The dowel joint will only be a strong as the dowel, meaning not very, even if you use epoxy.

The clothes pin scarph is not hard, especially if the extension is made from two pieces glued around the tapered end of the old piece and you use thickened epoxy. The carefully laid out joint can be roughed out with a saw and finished with a hand plane. Each tapered face will need to be about 12 inches long for a 2-inch diameter mast.

If done properly, the joint will be as strong as the rest of the mast, so it doesn't matter whether you add the length to the head or foot of the mast.

Brian