upper mast repair

[trv]

looking for optimal repair method for round hollow mast with rot about 4 feet down from top diameter about 5". The mast is round exact for squared-off section for mounting lights and radio, rot is quite visable only in this section (about 9") If we scarph a new upper section what type of repair would be best.

[paladin]

If the mast is hollow...make a sleeve and scarf in the replacement section on top of the sleeve. The scarf joint shouldn't be any trouble with a router......

[Ian McColgin]

I've gone at repairing round masts in two different ways:

Where there was some rot, but not all the way around, I just made dutchmen for the problem areas. This can be a bit like laying up Rubric's cube and you may want to practice assembly dry before adding epoxy.

For a broken mast (or if you had rot all around) I'd make a suitable length either duplicating the mast's structure (what I actually did) or with the bird's mouth structure (what I'd do now) and join it in with a couple of cloths pin scarfs. These are the ones that fit like:

heel===========>>===>>=========truck

Put a 'stop water' on the inside V to keep everything nice and not splitting.

This gives you good glue joining in half the overall space, and the bend of the mast will be close enough to original that you won't be introducing wierd stresses.

G'luck