Saturday 16 May 2015

Steaming Timbers - Part 2

The previously tested steam tube was lashed to the side of the boat so I could get hold of the timbers from inside the boat and the gas lit.  As I was unsure quite how long to 'cook' the wood for I prepared just two timbers by planing chamfers on the inner edges and slid them into the tube. I had read that one should allow half and hour per half  an inch of timber thickness. I decided to give them 40 minutes and that seemed to be just about right.  It seems to me that boiling the timber for too long will drive the tannic out of the wood making it brittle and more prone to premature decay. The first timber came out and working inside the boat I forced the hot timber down and persuaded it to touch all the lands before clamping it at the sheer. Then pressing down the other side and with the clamp not fully tightened the timber head was hammered hard to press it tight into place. The other soon followed and then I prepared another four timbers and forty minutes later these joined the others in their allotted places.
When cool these will be cleaned up and fastened and then another section of the boat will be stripped out forward of the mid ships thwart.
First two timbers pressed into place at last.
Mid ships set of timbers fitted ready for fastening.

Sunday 3 May 2015

Steaming Timbers - Part 1

I had prepared all the equipment needed to steam and bend in the new timbers whilst waiting for the oak to arrive.
The ribs in Nanw are longer (2.5m) than those I'd ever fitted to a Redwing or similar dinghy as she is a rowing boat and not divided by a centreplate case.  Therefore I had to make a new steamer.  For this I selected a 3m length of 150mm dia 'spiral duct' of galvanised steel; a wooden disc plugged one end and a batten was made to run the length of the tube to support the timbers being steamed. Insulated by old duvets, discarded by my wife, all held in place by cable ties.
Steam is provided by a large old kettle with electric element removed and heated by a gas burner. It is also arranged to use steam from a DIY wallpaper stripper which can be only be used intermittently as the generator that supplies power to the shed is 'only' 2.5kVA and all the lights have to be off to power the steamer!
150mm dia duct being prepared for use as a steamer
Steam producing apparatus in place. Bucket collects the condensation.