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Most of you have probably experienced the difficulty of making a perfectly symmetrical mould for longboats and bending pear-wood sticks 1.5 millimetres thick on sharp curves. The following is an explanation on another way to build launches. I am trying it to build the longboats on my model, following an idea developed by my friend Hubert Mallet who also recently designed the miniature precision saw. The description given is for scale 1/48, but all measurements given can be adjusted according to the scale used. To make things clear, I am adding some pictures.
You probably own or you have already seen a storage basket for a slides projector. Well, look at this basket, imagine frames instead of slides and you will immediately see the many advantages of this new way of building launches for your models. Extremely precise positioning of the frames, no gluing, nailing or screwing on the workbench, frames set in place and removed instantly for any necessary adjustments. To build this basket, you will need :
1) One plywood plank size 300 x 150 x20 millimetres. Bottom plank. Picture 1. 2) One plywood plank size 250 x 140 x 10 millimetres. Sides plank. Picture 1. This one will later be split into 2 halves. 3) Approximately 4 metres of reasonably hard wood 5 x 5 millimetres (space between 2 frames) Picture 1 4) 1 ‘’spacing’’ stick (picture 1) 160 x 5 and 2 (frames thickness) millimetres thick. Picture 1 5) As many (25 in my case) ‘’slides’’, rectangles size 70 x 100 millimetres in 2 millimetres plywood (thickness of the frames) Please do note that all rectangles must be STRICTLY identical.
The first step will be to make the 2 slotted sides of the slide basket. Draw on the second plank, lines showing the position of the 25 (in my case) frames using as a help a photocopy of the side view of the launch. Cut the 4 metres of stick into pieces of 140 millimetres. Glue these sticks (Loctite or similar glue) on the side of the lines using the spacing stick number 4. Do not forget to wax this spacer for anti gluing safety. Picture 2 shows this operation already half finished. Once this step is completed, cut the plank in 2 equal parts 250 x 70 millimetres and you have your ‘’basket’’ sides ready. Picture 3
Draw a symmetry line on Bottom plank number 1 and glue the 2 sides using 4 or 5 of your rectangles as spacers between the sides to make sure sides will be perfectly parallel. Your box is now ready. This explanation is probably longer than the actual work. Picture 4
Getting the slides ready. A good news first. This method does not require any frame drawing, hence saving time and lessening the chances for mistakes. On a copy of the plan showing the frames draw a rectangle size 70 x 100 mms (size of your wood rectangles) The bottom line should be drawn 18 mms below the bottom of the keel. Draw also the waterline and mark the place where the two parts of the frames are overlapping. Make as many photocopies or scan copies as you have frames and glue them on the rectangles using double face scotch tape. You may notice that they do not easily slide in the slots anymore because of the extra thickness of the paper and tape. If this is the case, trim both sides, removing the tape and paper on a few millimetres width. It is very important to give each rectangle a number (1 to 25 from first to last) to avoid mistakes when you will put them in place. Now you can scroll saw the slides. I have found convenient to underline the frame to be cut with a red marker to avoid cutting the wrong line, specifically in the middle section where lines are extremely close. Pictures 5, 6 and 7. You should also cut the keel shape where the keel will later be set for the framing and planking. Picture 8 shows a few of the finished slides
You can now start building the frames and it will be pretty easy. Using the slide as a guide, draw the inside line of the three parts needed, i.e. one bottom timber and two top timbers on a piece of pear-wood 1 millimetre thick. Still using your slide guide, glue them together and here you are. Frame number 1 is ready. Make sure you allow some extra width outside for adjustments. You will sand it once the floor and upper inside planking are made.
Some may find (that’s my case) that scroll sawing 1 millimetre thick wood is a headache. The wood breaks very easily. To solve this I am using a trick. I use 2 millimetres wood and build the whole frame as one piece. Then I sand the top of the top timber, turn the frame upside down and sand the bottom part of the bottom timber. You use a little bit more wood and time but I find this easier and safer too. Picture 9 shows the frames, finished but not trimmed yet. Put the slides back in the basket.
Build the keel now, including the stem and the stern post but keep the keel piece a couple of inches longer than needed in the front and aft part. (Picture 10) and put it back in place in the basket. (Picture 11) To make sure nothing will move, glue the extra keel length on a wooden base and immobilise the stem as is shown on picture 12 Everything is now ready for the frames to be glued in place. Proceed gluing them, starting from the back end. Once this is done, cut the extra length and remove the launch from the basket. If everything was made correctly, you should get something looking like picture 13. From there on, proceed normally, floor, planking, accessories…..
One last thing. Most people skip the nails in their launches as, planking being so thin, they fear going right through if they try to put nails. There is an obvious solution to this. Nail before planking. Mark carefully where the nails should be, bore holes, drive the nails in and glue them on the back side, sand both sides carefully and only then, glue the plank in place.
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