Puzzle Cabinet

Puzzle CabinetI’m delighted to say that the cabinet is finally finished and delivered. It was a long haul, and I’ve learned a great deal from it. It’s huge – eight feet wide – this is the first time I’ve been able to get far enough away from it to get the whole thing into the picture.
But at least if I do anything like it again it will happen a lot more quickly now that I’ve learned more about how large oak boards behave.

Finished with an American ‘wipe-on poly’, which is water-resistant and durable, and most of all, easy to apply and dries very quickly.

The client is fitting the lighting strips and the glass doors; when I see it loaded and complete I’ll add a photo of the result – watch this space.

Flattening a large board

router flattening jigHaving my large boards now jointed and glued, I now need to flatten them. Mulling over the problem in the small hours, I remembered an idea I’d seen in a book on homemade jigs. It’s a very simple idea; just make a gantry across the board that lays flat on the bench and has a slot just wide enough for the widest guide bush I have. The gantry was made from 25mm ply – the 18mm wasn’t quite rigid enough not to dip a tiny bit in the middle under the weight of the router. The jig sits about 5mm above the board and holds the router at the same height relative to the bench, so all I have to do is insert the dish cutter and set it to the right depth to skim the bumps off the top.

router flatteningAt first it didn’t seem to work very well; I tried going along and across and generally scribbling around with the router, but the result was a very uneven surface to which the belt sander was hardly equal. Since this is the ‘wrong’ side of the board it doesn’t matter – it won’t show – so I was undeterred.

I decided to try going across the board, moving the jig a little and coming back across. I got the hang of it quickly enough and did a couple of feet at a time. I let the router cool down while going up the grits with the random orbital sander to smooth the bumps, which were now much more predictable and recognisable. It turns out that I didn’t need the belt sander after all. smooth with ROSNo bad thing; the ROS is much gentler, even on a coarse grit.

I started with P80, then P120, P180 and finally P240. It took me just over an hour to flatten the whole 2.4m board. A sigh of relief was heaved. I know how to proceed, and I’m confident that it’ll be a good result. The only thing to watch for is the depth stop on the router, which does occasionally slip when I knock it accidentally.

It’s also essential to clamp the corners of the board down on the bench for this job. The flattening is relative to the bench, not the board, so the board has to be flat on the bench. For some boards it will also be necessary to clamp along the sides too; that just means I move the clamps as the jig is brought across. Similarly the corner clamps have to be moved when the jig is brought to each end of the board.

Jointing long boards

jointing setupWell, the jointing idea worked, thank goodness. The idea is that you’re not relying on each edge being perfectly straight, you just want the two edges to match each other, so you cut both edges at the same time. That way it doesn’t matter if the guide isn’t perfectly straight. I did, however, try to get it as straight as possible using a piece of thread stretched along it before tightening up the join between the two pieces of the guide.

I was casting around for a suitable spacer for the boards; it makes sense to have them close enough to cut both edges, but sufficiently apart to cut off the minimum amount of wood. The kerf of the saw blade is 2.2mm, and I found that a lolly stick is 2mm thick, perfect. Then I found that the lolly stick has a nasty habit of falling between the boards which makes it awkward to fish out again, so the solution was to drill a tiny hole and fit a piece of wire as a cross-piece. lolly stick

I’m managing to joint one board per day – that’s three joints per board. Seems slow, but there are several steps in the process: first check that the joint needs adjustment – about two-thirds of them have so far – then set up the saw guide with the lolly sticks and lots of clamps to hold the boards flat on the table, do the cut, undo the clamps and check that it’s OK, if not do it again. Then the guide has to be manhandled somewhere (I’ve cleared a high shelf) while I re-do the biscuit slots which again needs lots of clamping to make sure the board is flat on the table. Then test again and finally set up for gluing, and leave the clamps on for at least half an hour before moving it aside for the next one.

On the subject of gluing, I’ve discovered silicone brushes. Work a treat and easy to clean. I’m using Titebond III on this job.

All the 6-foot boards are done now, I’m halfway through doing the first eight-foot one. I’m glad I tested the concept on the shorter boards first.

And now I’m thinking about flattening the boards. Never had this problem with plywood… I’ve got a belt sander and a random orbital for going up the grits, but I think I’m going to try starting with a jig for the hand router to skim off the top before sanding. Watch this space.

Workshop revamped

workshop3My current project, the big display cabinet, is too big for my tiny workshop as it was, so I’ve changed it around so that I can work on the eight-foot boards in comfort – there is just enough room if the bench extends into the window recess. The work I’ve done on the boards so far was in the garage on a makeshift bench made from a piece of 18mm plywood across the table saw and roller stands. But it’s too cold to work in there at this time of year, and the glue needs to dry indoors anyway. So I’ve brought that piece of ply upstairs and supported it between the router table, which I won’t need for this project, and the workbench. Meanwhile I’ve made another bench along the longest wall for the lathe, the little bandsaw and other bits and pieces.

There’s a lot more room to work, even with the extra bench (though I did sacrifice the linisher and the floor standing bandsaw). workshop2There still won’t be room to assemble the cabinet in there, but I can at least work on the individual pieces and it’s very good for my biceps to carry the large boards downstairs to put it together. It’s going to be flat-pack anyway. It took me three days to do the rearrangement, make the long bench, put up the shelves and decide where to put everything, but it’s going to pay huge dividends in terms of the time to completion. For future large projects I might see about a neater bridge between the benches so I can get at the router table without having to manhandle an eight-foot by two-foot board and then find somewhere to put it. But time is of the essence, and this board will have a sacrificial purpose when I use the circular saw along the oak boards to joint them. I’ll set the saw a millimetre or so deeper than the workpiece, which will mean the plywood will develop some grooves.

Meanwhile, I think the workshop will stay like this for a long time. It never did feel quite right in its previous arrangement.

New workshop and standing desk started

DCIM100GOPRO

I’ve moved most of the tools up to the bedroom vacated by Elder Sprog, with the result that a) I now have a warm place to work – the garage is certain hypothermia in this weather – and b) I’m getting a lot of exercise moving stuff between there and the garage, where I still have to do the big stuff like cutting 8×4 sheets. Bandsaw, planer and table saw are still in the cold place, the rest is now cosy and dry. Still need to sort out lighting though. Meanwhile I’ve been asked for a stand-up desk for a freelance web designer, so that’s the current project. It’s going to be birch plywood – rapidly becoming my favourite material to work with and also highly recyclable; when a piece of furniture is no longer needed it can just be dismantled and made into something else. I mean yes, you can do that with any wooden pieces but I’m developing a good production line of boxes and chests from plywood because I like it and it behaves itself.

desk design1This is the idea for the desk, done in Sketch-Up. It’s to go in a corner and fits into a one-metre square footprint. That deep conduit along the wall is a challenge for the corner support.

So I’m having fun with the long cutouts in the uprights at the moment. Making a template first, because it’s very easy to make a mess of it and ruin the workpiece, especially on the join between the straight line and the half-circle, which even with rounded edges is going to show if it’s not perfect. There are myriad ways, as always, to skin this particular cat but what I’ve done so far is mark the shape, clamp on a circle template, go round with the router using a guide bush, set up a straight edge, go along it with the router and repeat steps 1 and 2 for the other side and end, leaving me with a cutout 3mm inside the line; the idea is to go round again with the flush trim router bit against the circle template and straight edge. What I should have done was to go round roughly – well within the line – with the jigsaw and then finish with the flush trim router bit. C’est la vie – setting up for a cut takes ages, and I’ve got to do it all again! But it’s all practice. Anyway when the template is done, I can do the same on the workpieces but without having to match up the guides for the circle and the line each time. And once I’ve got the template, watch out for cutouts just like it on other pieces:-) It’s a great way to lighten the piece, and gives me more offcuts for the little boxes.

Sawcut veneers

I’ve been asked to make a box to hold a venerable Mah Jong set. Thankfully the client isn’t in a hurry, because I’ve been struggling with the perennial problem of a nice piece of timber, bought from a reputable yard, measuring eight per flipping cent moisture content for heaven’s sake, twisting and writhing like a hungry python when I cut it into boards of the required width.

So I thought, well, plywood doesn’t do that (unless I leave it in a damp shed and then who can blame it?) but I don’t want to encase this ancient Mah Jong set in a plywood box. I could maybe make my own plywood so the whole thing looks more craftsmanlike. Then I remembered an article in a (luckily British) woodworking magazine by a real craftsman called David Oldfield. about sawcut veneering, and revisited the article. It turns out that it’s perfectly respectable to use good quality plywood as your substrate, and put your thick (3-4mm) bandsaw-cut veneers either side of it (which you can bookmatch and all sorts).

My planer/thicknesser only goes down to 5mm, but that’s OK because if I cut a piece thinner than that it can always go through the thicknesser after it’s been stuck to a piece of 6mm Baltic birch plywood. And I’m starting to get the hang of resawing on the bandsaw, thanks largely to a wonderful resaw guide by Magswitch – spensive but what a difference!

Anyway, so the aforementioned twisted boards aren’t so bad when a) sawn in half lengthwise and b) sawn in half widthwise with a view to bookmatching and c) glued to a nice piece of 6mm birch plywood. That’s the plan anyway, watch this space.