tkay11 Posted February 23, 2019 Author Share #61 Posted February 23, 2019 (edited) Thwart lodging knees Thanks again for all the kind comments and likes. I’ve managed to squeeze in one last log before my enforced absence. As usual, I predict in advance that I’ll have difficulties by preparing several copies of the tracings I need: in this case of the thwart lodging knees. I use these templates to fix first to card, and then, once it all seems ok in terms of fitting, would use them for the final wood knees. I really used them up this time! In order to take account of the possible variation from the plans in the shape of the bulwarks and frame positions, I cut out the templates leaving plenty of extra space on the bulkhead sides. I knew I’d have a bit more trouble with the foremost lodging knees because of shaping round the octagon of the swivel gun stocks. At first I just used the card template and cut out all the notches for the stock and frames at the same time. But the cut for the octagon just turned into a mess as I tried to fit the card to the bulwarks. Second time around I realised that the primary cut would have to be for the octagon as this would determine the position for the remaining cuts. So I cut out an undersized notch for the octagon and, from a position above the bulwark, gradually shaped it to fit using a small chisel. Having got that right, I then shaped the outline to fit the bulwark while keeping the orientation of the octagon, and and only then marked the cutouts for the frames. Accurate placement of the knees also required bevelling the sides against the bulwarks – including the sides of the notches. Finally, because the thwarts sit proud of the stringer by 1mm, it is important to mill out a 1mm cut in the bottom of the knees so that they fit flat over the thwarts. It was only after fitting the fore lodging knees that I remembered that their edges had to be moulded. Earlier in the guide, when talking of the moulded timber along the axis of the apron, it says ‘The moulding is nothing more complex than a quarter-round worked on each side. A miniature moulding plane should be made up for the purpose, with a circular hole at the edge of the blade of the same diameter as the cutting disc. Put it aside when you have finished, because we will need it again for several other timbers’. I wasn’t sure how to interpret this, so I made the moulding plane with the following shape: It then said with respect to the thwarts that ‘the upper edges are worked to a quarter-round’. I assumed that the same scraper would be used but, as you will have seen in the photos of the thwarts, the outcome was quite patchy. All the same I persevered, and when it came to the mouldings for the lodging knees I again used the same scraper hoping that by now my technique would have improved. The following picture shows how the mouldings SHOULD have turned out (the photos are from the guide): I tried holding the scraper at right angles and then at a diagonal to the knee, but unfortunately the roughness and variability turned out much the same. So I assume both my scraper template and technique are wrong. I’ll experiment a bit before I go on to the cabinets at the rear. That will be when I’m out of hospital. In the meantime my first proposal for a template is as follows. I think that one of the problems was that although the shape was roughly correct, there was no way of centring it to the thwart or knees. Any comments or advice are welcome in the interim! Thanks again Tony Edited February 23, 2019 by tkay11 JpR62, Jeronimo, G.L. and 7 others 10 Quote Link to comment Share on other sites More sharing options...
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