Thursday, February 26, 2015

SCAMP Camps and more mast making


SCAMP Camps and other things.
Its going to be a busy few months from July onward. With partner Howard Rice I’m involved in three SCAMP camps, one in Port Townsend, One in Baldwin Michigan, and one in Port Aransas.
I’ll be running tool skills classes entitled Essential skills for the Beginner Boatbuilder” in Port Townsend and at Port Aransas as well as being involved in sailing classes at both of those venues.
The tool skills classes cover use of planes and chisels, drills and countersinks epoxy glue including making joints, coating and using fiberglass and making taped seams, reading plans and drawing out full sized ready to cut, setting up and using some of the  big tools such as bandsaws and sawbenches, use of sanders, angle grinders, jigsaws and so on.
More than enough to give you a flying start to your boatbuilding career.

The schedule is “here”  http://www.thepocketyacht.com/

See you there!


I’ve had several off blog questions about cutting scarf joints in the staves for the birdsmouth masts I’m making.

Its no big deal, an accurate angle cut in each piece and a means of clamping them together and protected from any contact with anything else so the glue wont stick the assembly to anything else.

To make the angle cut, I’ve taken a piece of heavy plywood, glued and screwed a rail on the underneath.  That rail is of a size that slides easily in the groove in the sawbench table.

I then ran the plywood on its rail through the saw to get the edge accurately lined up with the saw blade.

On that plywood I screwed and glued a rail, 20mm square, at the right angle for the scarf joint, and fitted a section of the mast stave alongside it, then screwed, one screw at each end and no glue another stave on the other, the saw, side.
Next was a block to make it easier to fit a clamp to the assembly.
The clamp springs the screwed but not glued rail against the stave to hold it.
Make sure that the clamp is well clear of the saw blade.
Next was a handle with which to push the “sledge” through past the saw.

Views of Sledge.  






It is important to keep the end of the stave up at sawbench height as its run through, but otherwise once built its very simple to cut perfect scarf slopes.

Joining them up.
I’ve a stack of Australian hardwood 45 x 90 lumber.  Dead straight, ideal to clamp my pieces to.

So with kitchen wrap around each piece, they’re coated with epoxy and clamped up. Leave them for a day or more and you’re done.

Clamping up.





Finished scarf.  Note that these are 5.5 / 1 scarfs, plenty strong enough, but if you are at all concerned about the accuracy of your work you can increase that to 6/1 or even 8/1.  But not less, my test rig has verified these figures.







3 comments:

  1. thanks for these last two blogs
    you have simplified what was, in my mind, a complicated process
    I'll use your system building the mast for my Duck Punt

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  2. Excellent illustration. My sledge will be improved by the handle. Thanks.

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    Replies
    1. It sure helps to keep your fingers away from the saw blade, no matter how well you mix the epoxy it does not seem that well suited to putting fingers back on.

      JW

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