Fitting the sheer clamps

While the first coat of epoxy was curing, we made a start on fitting the sheer clamps. These are strips of timber that run along the length of the boat, forming a structural junction between the top of the frames and the deck. Obviously at the moment the top of the frames is the part of the boat nearest the ground. Given that our boat is open, Si designed our sheer clamps to be made up of two layers of Douglas Fir to produce a substantial laminate to stiffen and strengthen the hull.

So far, most of the jobs on the build have been straightforward. Some have required more thought, skill or experience than others, but most have been relatively simple to accomplish with a bit of patience and concentration. Fitting the sheer clamps was the first task we have taken on where we felt we were stepping into the world of more skilled boatbuilding, and we are so grateful that Bob (lovely and excellent carpenter and boatbuilder) was around to give us invaluable help and guidance with the job. We are lucky to have him so close by.

Given that each sheer clamp needed to be about 20ft to cover the length of the boat, we made each one up out of three pieces of Douglas Fir joined together with a scarf. By scarf I obviously mean a nice woolly cashmere one rather than the woodworking type where you join two bits of wood together by glueing one tapering flat surface to another to form a continuous unbroken length.

We fitted the inner sheer clamps on each side first and fastened them at the bow with an oak knee (triangular piece of timber which fits between two bits of wood being joined, a bit like a shelf bracket), which we bolted through at the stem with a stainless steel stud. We also epoxied it to the clamps themselves and secured it on each side with what is essentially a really long screw, but which Simon assures me is called a ‘lag’. Always nice to learn new words for these things.

Once the glue and epoxy had gone off on the first set of clamps, we glued the outer sheer clamps to these and clamped everything in place while the glue dried. There were a lot of clamps. Despite having collected as many G-clamps as we could before starting the job, we still ran out. As more than one wise person told us when they first heard we were building a boat, ‘You can never have enough clamps.’ They were right. We didn’t. But we did have a bit of rope and a stick which combined to form a sort of tourniquet technically known as a ‘Spanish windlass’ which held the sheer clamps in place in the middle, and a bit of rope, two blocks and a jamming cleat which pulled them together at the stern. And combined, they held the whole thing more securely than twenty G-clamps!

We’re really happy with the finished sheer clamps and even more happy that we can now begin planking. There are a couple of small changes that we felt could be made to the design of them from a fitting point of view, so Si’s going to have a look at modifying these and a few other details on the design for any future boats. But overall we are really pleased that the design is working out as Si planned and so far we are confident it could be built by anyone with a reasonable amount of common sense, determination and some really nice friends.

Advertisements

2 thoughts on “Fitting the sheer clamps

  1. Richard Smith says:

    Hi both… it all looks amazing! Love the torniquet… and all the terminology. I have a materials theory class tomorrow and will show them this post!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: