Tonight was mostly cleaning down from the weekend. I broke down the jig, saving the screws and while the sharp hammer blow took care of the glued on blocks, it did it by removing the block and the top millimeter of the MDF. Oh well. Have to rebuild it anyway. Need taller blocks and I’ll probably cut a bit of the MDF base off to make a drying form as well (the idea is you bend it on the bending form, let it on that, then take it off, remove the bag and the strap and all that, and then clamp it to the drying form and leave it there for a week to dry and set fully).
Then it was time to start in on the next eight slats for the cot. I got the remaining half of the 72″ ash board I got the last eight from and cut 31″ off that (the ends were a bit ragged so I left room to trim it back to 30″), and brushed off the muck.
Kindof mucky still really, but that’s what you get if you sit about in a timber yard for ages and then a shed. But fifteen minutes with a jack plane on the faces, edges and on the ends with a shooting board later…
It’s just lovely. It feels like slightly textured glass, there’s lovely grain in it, it’s just downright pretty. It cleans up well 🙂 It was almost painful to mark it up, but it needs to be broken down so I set the gauge to 46mm (it’s 189mm wide) and marked off the first lath. I’ll rip that out tomorrow, then plane a fresh clean edge and mark the next and so on. Ash is pretty. I need to buy more of it 🙂
There was some experimentation this weekend, some of which didn’t work and the rest of which were… learning opportunities. I got the last slat planed to thickness, but lost one along the way because I couldn’t get it to thickness, there was a split in it from poor resawing that was diving down below the minimum line and it wasn’t recoverable. So next week I’ll take another 30″ off the ash board I have, plane it flat, hack it into 2″ wide laths, and resaw them down and wow does this ever teach you why we invented bandsaws.
Meanwhile, I had two experiments to run. One was to try to avoid drowning in the growing mound of shavings I’m generating…
Honestly, it’s getting silly now. I’ve lost two clamps to it. Seriously, somewhere under there is a sash clamp, a lidl F-clamp, four boxes of lawn seed and a container of round-up. And normally you’d just use a broom, but the space is so small and restricted that a broom would honestly be more hassle than help. So I got an aldi wet-and-dry shop vac and tried that, but while it could grab the dust and some shavings, the shavings clogged it up pretty fast. Well, there’s a solution to that – it’s a thing called a cyclone seperator. Think of a conical funnel with a lid on it. The vacuum connects to the lid, and you connect another hose to the side of the funnel angled to cause the incoming stream of stuff to spin, whereupon is slows down and drops to the bottom of the funnel and into a barrel mounted there.
And there it is…
…but it doesn’t work. There’s very little suction, because it leaks air everywhere. Normally the barrel underneath would be air-tight (they’re normally used to store liquids after all), with a seal in place around the lid. Here, it’s a bin and the lid is a chunk of mdf clipped in place by the handles. I suppose it was asking a lot of physics 😀 I’ll have to find a proper barrel, pay more attention to seals, and try again. The bin will go to waste, as in, I’ll use it as a bin for garden waste, but I foresee a trip to somewhere that sells barrels soon. Which, oddly enough, is a very short list it seems. I’m a bit hesitant to order one off amazon because who the hell posts a barrel? I’d never be able to look the postman in the eye again. Not to mention the point that if the Firearms Unit hears I’m getting barrels posted to me, they might take it up the wrong way…
The other experiment, which went slightly better, was to test steambending walnut. The idea is simple – wood is stiff because of a (fairly complex) chemical called lignin. It melts around 150C (well, there are several melting temperatures because your average tree will have lots of slightly different lignins – apparently it’s a challange for people studying the stuff to seperate them out, there are so many), but it will soften around 100C which is a nice convenient temperature as you just have to generate steam and that’s fairly easy.
So the theory is, take the wood, expose it to steam for a time (the rule of thumb is one hour per inch of thickness), then clamp it into a jig and bend it to the desired curve. This is normally done with a sealed box of some kind (either made from wood or PVC pipe or whatever) and then you pull the wood from the box with big thick gloves and as quickly as you can, clamp it into the jig and bend it before it cools. You have to bend it beyond the curvature you want, as it will spring back and how much overbending is needed is something you need to know by experience. Lots and lots of videos up on youtube show how to do this, but to be honest, they all looked like high-waste kinds of learning processes — especially because I only have kiln-dried walnut and this process really works best on something that’s never seen the inside of a kiln — and I didn’t feel like trying them at all as a result. And then I found this:
But anyway, his genius idea is to encase the wood in a plastic tube – specifically, the kind of continuous poly tube that you’d make smaller bags out of using a heat sealer – and pump the steam into that tube. That lets him put the wood in the jig, steam it for an hour, then bend it while still steaming it and hold it in the bent shape in the jig while still steaming it and then control the cooling-off process. Apart from the benefit of being able to work on long timbers for boat hulls, which is his thing, he gets lots of other bonuses, like being able to take his time doing the actual bending, controlling the temperature seperately from the bending process, and being able to keep the lignin softened even after the bend is done, and letting the stresses in the bent wood settle out before letting the lignin harden. This leads to far less spring-back to cope with.
I took one look at this and thought that’ll do. So I get a wallpaper stripper, some poly tube (it’s very cheap on ebay) and some metal plumber’s steel strap and prep to get bending. The strap is needed to go around wood on the outside of the curve – the reason the wood is bending at all is that with the lignin softened, you can compress and collapse the inside of the curve. You can’t stretch wood y’see, it’ll snap and splinter if you try, so the strap keeps the outside from stretching and the inside in compression.
This was, incidentally, one of the mistakes I made – I forgot the strap until the wood had been steaming for a half-hour and had to make up and apply the strap while the wood was around 100C. That does not lead to fine tolerances and unrushed work.
The first step though was to build the jig, so I needed a flat surface and some blocks around the curve to clamp to. I had a few sheets of MDF that I don’t really want to save for anything because honestly, MDF is awful. So I glued enough together to give me an inch-thick slab of MDF, and I started laying out where the blocks should go.
Then lots of drilling, a quick run to woodies because none of the screws I had were up to the job, and then screw&glue the blocks in place. That may have been a mistake, but not an unrecoverable one; I’ll need to disassemble the jig and rebuild it, but a solid belt of a hammer might fix that glue problem.
Then put the walnut offcut I’m testing with into the tube, being sure I had a half-meter off either end, and put in a spacer (in this case a paper cup) to stop the tube from collapsing on top of the steam pipe and melting because of a high concentration of moisture and heat.
And then it’s just a case of clamping one end of the wood into the jig, filling the wallpaper stripper with water and plugging it in. It takes 20 minutes or so to get up to 100C and then start steaming, then I wait an hour (actually a little bit more because the steamer ran out of water before I was expecting it to and it took a few minutes to refill it so the temperature dropped for ten minutes), and then I start bending.
The bending itself is not exactly a delicate operation. You don’t quite get out the hammers, but you put on gloves and oven mitts, grab the wood and then it’s just muscle to pull it into the bend. You grab it with clamps as you go and then it’s a case of pull it to bend it a bit, tighten the clamps to hold that, then pull some more and pretty soon you’ve got the bend in. If you’ve not heard any loud splintering noises, you’re good.
Now leave the steamer finish off the last of the water that’s in it, so another half hour or so of steaming, and then unplug the steamer and start letting it cool down.
Now there are a few mistakes I’ve made here. For a start, I forgot the compression strap until half-way through the steaming and had to put it on outside the bag.
It’s also not the full width of the piece being bent, so a good bit of the wood is not supported. And then there’s the point that there’s no scrap bits of wood between the clamps and the wood being bent (and of course, as the wood is being softened, the clamps really dig in and deform the wood.
On the left, the supported and properly bent walnut (still quite damp); on the right, the unsupported part that split. Still though, I’m not too unhappy. I know what to do now for the real thing. But first, I want to watch that experimental bit for a few days to see how much it springs back and how much overbend I’ll need. I will need to rebuild the jig though – those blocks are not tall enough off the mdf to do the job and need to be redone. I’ll also want to make up a proper compression strap setup and some scrap bits to protect the walnut from the clamps.
And all that in the middle of being swallowed whole by a slow-moving avalanche of wood shavings as I resaw another 8″x30″x1″ ash board. And I want to get that all done before I go buy more wood on Friday…
So the early start plan kinda went to pot because of other duties, but I did manage to get to woodies and get another tin of the willow colour of paint to do the second coat on the shed. And then, annoyingly, got the second coat out of the remainder of the first tin. Gah. Oh well, I’ll find something for it. Meanwhile the shed’s looking okay, but I didn’t manage to get the first coat of the cream colour on it, so that might make getting everything finished tomorrow a bit of fun.
Can’t say that it looks like a massive difference with the second coat, especially as the colour darkens very noticeably on drying, but this stuff really does need the second coat when you look at it close up.
Then on to getting the cheese press done. I picked up the needed bits of threaded rod and such at woodies while getting the paint.
The threaded rod will get cut into 1′ long sections to form the two side supports and the main screw and the various washers and nuts will secure it (the hooks are for my bench brush which is in need of a better home than hanging on the quick-release of the vice).
The more difficult part of this has been getting a 2×2 chunk of wood down to something that vaguely looks like a handle if you squint and are blind. I was able to saw out a big chunk of the waste, and carve the basic shape very roughly with the gouges, but trying to get it even close to smooth was being a pain so out came the spokeshave, which promptly tore the crap out of the surface no matter how I twiddled with it. So I took a tip from Richard Maguire’s spoon rack series, took off the adjustment knobs completely, and set it by keeping the base flat on the bench and letting gravity put the blade in contact with the bench, then tightening the clamping screw. And it worked like a charm. It went from biting and skipping and destroying the face of the wood to looking like an actual woodworking tool being used by someone who was competent. Not sure how it managed that last bit, but I wasn’t complaining much. Before long I had an ugly lump-shaped chunk of tree branch and figured I should stop before I broke it too badly.
Some butterfly nuts on the two side supports to cinch the crossbar on to the top of the cheese vessel, and a chunk of wood on the bottom of the screw to push against a plate in the cheese vessel and that’s your cheese press, more or less. First, some nuts needed epoxying and there was a small void to fill on the face of the board.
Tomorrow I’ll clean up the boards and get them flat and shellac them, add the block on the end of the screw and I think that’ll be it finished. It’s not a very fancy thing after all. I’d like to put some springs on the side bits of threaded rod, but I couldn’t find any. Oh well, easy retrofit.
Of course, that last spokeshave session had a casualty…
I know I said I’d make a hardwood vice face later on, but I think it might be sooner than I thought. I re-screwed it on, but I don’t want to glue it and I’m not sure those two screws are going to last. I’ll have to think about this one.
First though, on to resawing ash for slats. One or two of the resawing boards tonight were pains in the fundament with the blade wandering out of nowhere, but I was able to use the disston to get the line back on track and finish the cut without losing a board. Which let me write a very nice number indeed…
20 slats out of three boards, with another three definitely unusable and another one as a very marginal call (ie. use it if we really need just one). That’s all the original plan called for. I don’t doubt I might find I need another two or four more, but I’ll try not to 😀
In case anyone was wondering, yes, you can resaw 1″ thick 8″ wide ash boards by hand, and it’s not actually the most strenuous job in the world… but it’s not a lot of fun either really, and it can be finicky keeping the blade from wandering. As soon as I’m able to house it, I’m going to get a bandsaw.
Now, for the coming week, it’s planing in the thicknessing jig to get those 20 slats all down to size…
So I was wondering if ripping the 8x1x30″ board down to four 2x1x30″ laths and then resawing those was the better way to go. And now I know.
Yes indeed. Much more accurate resawing, the worst variance was yesterday’s 2mm deviation, and much less sweat involved either (I’m not saying it’s easy you understand, just easier…)
So that’s twelve slats down, eight to go, and now I have to ponder whether I break down the 60″ board I have into two 30″ boards and use one of those and have the other in reserve and save the 34″ for something else; or if I use the 34″ board for the last eight slats and keep the 60″ in reserve. I’m leaning heavily to the former on the grounds that I’m going to do another timberyard run later this month.
I also got to try out some new tools. So I used slat #1 in that pile as a test run earlier, but even with my smoother on the wispy setting, I couldn’t get rid of all the tearout on the slat, there was one portion that had awkward grain. I did have a plan for this, but first I needed to make a jig for a file.
I don’t care that it’s not vital and I don’t care what Paul Sellars says about dogs and end vices, I think that thing is great 🙂 It would have been a right pain in the fundament to do that routing job against a planing stop and the face vice was warping the wood slightly (this is yet another on the list of JigsIWillHaveToMakeABetterOneOfLaterWhenIHaveTime 😀 ).
I haven’t had a task for this little guy either, I knew I’d be using it on this project so I bought it earlier off ebay, but it’s been languishing in a box ever since. Perfect for this though.
Few minutes with a smoother and a pair of thin wedges because it’s not perfect but who cares, it’s a pine jig, and I had a fence for my file and I could get on with sharpening my card scrapers. I do have a #80, but I cleverly took out its card and put it somewhere safe, so I’ll have to go digging to find it again. Till then, we do it by hand.
And wow, does that work. Almost exactly as advertised, and I think the slightly-more-fiddly-than-I-was-expecting bit was down to a poor sharpening job rather than the tool (the cheap chinese burnishing tool I have is, I think, not a burnisher as the card scarper was grinding small gouges into it…). I am going to need a better burnisher, but this puppy’s getting used on the project for certain and definitely earns itself a place on the wall.
You can just about see in that awful photo the part where the grain gets squirrelly, and that was tearing out in both directions with the smoother – with the card, it’s now glass-smooth to the touch even though it still looks squirrelly.