Monthly Archives: October 2014

On finding and milling a keel

As has probably become fairly obvious for regular followers of this project we’re going to be building two West Coast Skiffs in the GalGael workshop over the coming years. These bonnie boats are 20 feet long and traditionally built, meaning they are built of larch planks rivetted together to steam bent oak frames around a central backbone.

As we’re in the early stages of the build we are most worried about the keel at the moment. It’s surprisingly hard to find a keel for a boat this big, mainly because we have such stringent requirements. So we went looking for a bit of native oak, 17 feet long, at least 2 1/4″ thick and 5 1/2″ wide, it needed to be dead straight, and ideally air dried. We’d always rather buy native timber because it’s better for the environment, better for local industry and more traditional. Our first piece was too thin and had to be sent back. After calling just about every timber yard in Scotland we gave up on native and bought a beam of Greenheart (Chlorocardium Rodiei), this South American hardwood is a very strong and heavy, it can make a great keel. Unfortunately the piece we got was not straight enough and it too had to go back. Finally we went to McConnel Wood Products, a supplier of oak beams who sourced for us a truly massive board of French Oak.

Big Ol' Oak Board

Plank of oak on one of our boat trailers.

The board was 5.5 M long, over a meter wide and 65mm thick. Far too heavy to lift off the trailer without about six guys working! So first we had to reduce it in size, cue a circular saw and lots of dust.

2014-10-16 11.10.55  2014-10-16 12.55.58

The photos don’t quite give an idea of the scale of the piece, but it’s pretty huge. With the piece small enough to move it was through to the machine shop to mill to size, first on the the table saw we cut it down to a manageable width. Then on the surfacer to flatten out the twist, and the thicknesser to get it to finish thickness.

Big Ol' Pieces

Cat and Brian milling the keel to thickness

And finally it’s straight edged, and back onto the table saw to finish it width accurately. Back to the lofting in the end we lie it down in place, with the part finished stem as well we are finally starting to get an idea of the size of the boat.

Yowsers!

Keel and Stem in place on the loft floor

All that work for one piece of wood, luckily they are not all that big.

Bending New Frames

Another few weeks have passed and everything has inched that bit further along. At the Tall Ship we’re deep into the process of reframing Starcrest. In order to maintain the shape of the boat we start by supporting the boat as best as we could. So we’ve block her up underneath; drive wedges up against the planking and support the hull from a beam built into the roof of the workshop. Inside the boat we have added bracing that runs across the boat, adding extra strength wherever we can. Then the laborious work of removing the frames begins, every second frame is taken out, each rivet ground off and driven out and the old frames cut out.

The exposed areas of the hull are cleaned up and inspected for damage, in many cases this has been the first time areas have been looked at in 90 years! So we’re alert to the chance of rot.

Then we are ready to bend in the new frame, we have a huge stock of fresh sawn green oak. This timber has to be totally straight grained and without checks or knots. It is milled to shape and has the corners chamfered, the chamfering helps to resist the tendency for the timber to start breaking away.

Each piece goes into the steam box for a set amount of time, the rule of thumb is 1 hour per inch of thickness, so the 3/4 inch frames get 45 minutes in the box. The heat from the steam softens the bonds between the fibres of the wood and allows them to bend so we need to be sure that the heat penetrates right to the heart of the timber of we risk it snapping. Wood doesn’t stretch, so as it bends the inside face compresses.

As soon as the piece comes out the box its hot and cooling fast, the guys have to work fast to get the piece into it’s finished place before its cold. It has to slither down between the hull and the stringers, so they push, pull and hammer it home. Using clamps, sticks and a pneumatic jack they push it to the right curve. And leave it to cool.

After it’s cool the no less laborious task of riveting it in has to be done, another task requiring team work and precision. But meanwhile there are fifty more frames to do, and that’s only half of them! It’s a slow job framing out a boat.