Thursday, 19 January 2017

Saw Till Part 1

The New Year of 2017 gets underway at TMC Woodworks with something I have been threatening to make for a while. I have a large collection of hand saws and currently don't have a neat way of storing them. They are just hung on a few pegs on a board which is in turn hanging on a French cleat.

I need to change this arrangement

I saw a free set of plans for a Galoot Saw Till from Popular Woodworking which seemed ideal so I adapted the plans for my needs. Mine roughly follows the size and shape but instead of an open space at the bottom I installed two drawers instead. I also dispensed with the multiple sections making up the rear panel. There was a design flaw in the way that the upper crossmember was installed. The original had used dovetails. The pins in the side boards had been cut so they presented the direction of the grain to the crossmember. This is inherently weak as the pins could just shear along the grain line. I decided to use mortise and tenon joinery for this component instead.

The top left of this image shows what I mean, The pins in this configuration add little or no strength as they are cut with the grain direction. If you were to hang this from the crossmember it could fail if subject to loading.
Here is my version of the sawtill

The sides of the original could be made from a single long board if you take care when cutting the profile. Unfortunately I didn't have sufficient stock on the shelves in the shop to make it as designed and I only wanted to use what I had. So like a good woodworker I compromised with what I had. I found a couple of pieces of western red cedar left over from a project so glued up a fabrication to gain enough stock. As I started just before New Year 2017 it was cold in the shop and when one of the glue ups came out of the clamps it sprung apart at the joint line. Essentially the yellow glue hadn't cured due to the low temperature. I also found that the cedar was awful to cut dovetails. It simply does not have sufficient resistance to deformity. When cutting dovetails by hand with saw and chisel the stock does need to be able to resist some pressure when chiselling. Cedar is too soft and I had wasted a couple of days on this. A new years break, work and some theatre work then got in the way of anymore shoptime for a few weeks

So back to the drawing board mid January I found some iroko and oak on the shelves so remade the fabrications again this time using West System epoxy. Obviously the sawtill would be a lot heavier now as iroko and oak are very dense in comparison to cedar. The first job was to mill the rough boards, make a glue up to get enough stock and when cured cut the side panels to shape. I cut the sides whilst they we stuck together with double sided tape.

I am a tails first person when it comes to cutting dovetails so I set about making the tailboards first. The side panels only needed tails at the bottom to hold the lower panel in place.

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