The Mk3 mast thwart is longer than the older Mk1&2 models so I start with preparing a section of Iroko out of 25mm sawn stock boards, this comes in at approx. 28mm in thickness.
It is planed square edge then thicknessed to 22mm. For economy I maximise on the board’s length and width, so choosing the best board to convert that will give me the optimum number of product pieces with as little waste as possible.
If there is going to be waste as more often than not I have a second cutting list that will identify what that waste can be converted into.
In this instance out of the 3m length board I got 4 mast thwarts and a 3m off cut strip of 70mm wide. This offcut was identified and put to one side for swimming ladder steps at 380mm long x 60mm wide, these will be manufactured at a later date. All sensible material management to ensure as little waste and time expended as possible.
I have cut the 4 thwarts to length and width and firstly marked out the slot for the mast step position. This is to cut the majority of the waste out of the slot before forming the nice and accurate step slot with a router cutter.
To make it easier to cut this rough curve with a jig saw, cut straight lines to relieve the curved cut, it’s 22mm in thickness. You can see the segments dropping out as you are cutting the curve.
Always where possible make up a profiled jig when using a router, it’s gives more surface area for the base of the machine, it’s more accurate and most of all safer!!!
This shows the trimming cutter with its underside bearing follower. This former is under the work piece, so the bearing being the same diameter as the cutter will replicate the surface that the bearing is following.
This is showing the close up of the Thwart corners and the profiled edges to the thwart.
All 4 will now go through my power fed sander to clean up the surface and be ready to be racked into my stock area.
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