Oh, and regarding silver, if I were you, I would start by using nickel silver (german silver) or brass. It is much less expensive, and perfectly functional. The tools and techniques you use with it are just the same as with real silver, so you can always switch to the fancier material later when you have everything dialed in. You can also buy precision tubing in sizes such that it telescopes together, for use in tuning slides. You can also get it in sizes suitable for rings etc. People typically use a 0.5mm wall thickness, but antique instruments used a bit thinner that, and that may also offer acoustic advantages. I haven’t found a source for nickel silver under 0.5 mm, but there are plenty of sources for brass tubing with thinner walls, and that might be the way to go for tuning slide. If you don’t like the look of brass, you can always hide it under a very thin sleeve of wood over the outer slide. I do this on some of my flutes, for a more organic look. But note that I use stabilized wood for this thin veneer. This is a situation in which unstable wood can easily crack since the underlying metal will not move when the wood shrinks.
Thanks Paddler for emphasising the point on resting the wood at different points in the process. I’ve taken that on board. Of course there’s always Delrin or Ebonite! Or resin stabilised wood if one can find it big enough (for most of us who don’t produce it like you!).
And of course if an instrument cracks it’s not necessarily the maker’s fault. People can and do treat musical instruments like the proverbial and if the wood cracks it’s their doing. Not sure what sort of warranty should be offered that would be fair to both maker and customer. I’m only wanting to learn to make the beasties - haven’t given much if any thought to actually selling them (it seems a long way off from this point).
I had tentatively thought brass for the tuning slide but nice shiny silver for the metal bits on show. Might be an idea to go all brass until I know what I’m doing. Actually thinking about it some of the tuning slide does usually show so maybe the brass/silver thing is a bad idea.
I have used a gun drill as a reamer for very short sections on a couple of occasions. I wouldn’t want to do it on anything really long because it’s a bit hard on the sinews. Plus it is very slow. But I typically drill everything twice and I haven’t found it necessary to re-ream. I turn my stock round and let it rest to get its wiggles out. Usually it moves a little bit, and might even bend slightly. Then I true up the OD again and watch to see if it moves any more. If it looks stable, I bore it out. Then I seal the bore with some thinned epoxy and let that cure in a heated curing cabinet. This does make it shrink slightly (depending upon the wood). Then I drill it again and turn the OD. At that point I haven’t found that they shrink or move enough to matter, but I also tend to make flutes in a style where small dimensional changes are not going to have any negative (or perceivable) impact. When I’m making anything that is going to have a joint, a slide or multiple parts, then I use stabilized woods or ebonite, which is sort of cheating .
And though I wouldn’t advise re-drilling a finished flute or whistle, it can be done. It is a somewhat dicey proposition, and one risks destroying the work. But I’ve re-drilled some long and thin-walled instruments successfully. Describing the method would be a big digression, but it involves 90 degree angle stock made from aluminum and a lot of duct tape . And patience. Not for the faint of heart, however.
Getting set up to do your own resin stabilizing is not too cumbersome, really. This is especially true if you are doing small stock. If you are looking to make high D whistles, then you only need to manage with very short sections of wood, and this means a smaller vacuum chamber, smaller quantities of resin, etc..
Paddler and Loren have both highlighted a major obstacle that I encountered along the way, and that is the necessity of using thoroughly settled timbers. This takes a lot of foresight and patience, and I’ve never managed it. I’ve been privy to paddler’s process with this over the last ten years and it is beyond impressive–he has stockpiled an envy-inducing collection of flute timbers, committing to the time and effort needed to process it through various stages and then to let it settle properly. I’ve seen photos of his wood collection, and it makes me drool a bit .
The dilemma I faced (and the reason I rely on resin-stabilized wood or ebonite) is because I couldn’t realistically pull this off because I’ve chosen to make too wide a variety of flutes. If I focused on a single type then the task of sizing and preparing suitable stock would be, if not easy, then at least manageable. But to provide for all of the different types of flutes I’d have to have a ludicrous quantity of woods in all of the various stages of the process–I couldn’t afford that much material nor could I store it (it would need a small warehouse to accommodate it). But if you focus on a single type of instrument with limited variations in size, you can store a lot of “resting” stock.
But on the subject of reaming, I had meant to comment further on the reaming versus drilling piece. I have bought and used some straight reamers, which was easier than making my own, and frankly they were better. But I’ve also manufactured my own for special jobs. The argument for re-reaming versus re-drilling is perhaps that it is safer, less likely to cause problems with stock whose OD has been turned near to its finished size. When you get thin-walled stock you risk rupturing it when you attempt to re-ream it (or drill it). Stock with a thicker wall, such as you’d find on a conical bore flute or a recorder, will bear the process better, especially if you have nice, sharp reamers and you go slow and easy. But I have not found reamers to be any more delicate than a gun drill when you are dealing with thin-walled stock. You face the same dangers. Thin-walled wooden tubes flex a lot when something like a drill or reamer are traveling through them–you can really feel it if you are holding the stock and feeding it onto the reamer or drill. I have cracked my share of thin-walled stock doing this very thing, both with reamers and drills. Usually this is the result of impatience–moving too quickly, and not taking enough trouble to support the stock from the outside. And I think this is the advantage of a reamer–you can choose to go very, very slow if needed. Especially if you have a way to manually turn the reamer, as opposed to having the reamer mounted in a lathe chuck where you can only set the speed to go so slow (unless you have a lathe with a variable frequency drive or the like).
My own gun-drilling set up has such a drive, so I can run it with infinite variations in the speed between 0 and 1200 RPMs. So if I choose to re-drill something, I can go at 10 RPMs if necessary. Typically when re-drilling I haven’t needed to go slower than around 100 RPMs. But the trick is finding a way to support the thin-walled stock from the outside. I’ve gone as far as wrapping the stock duct tape to prevent marring and then putting hose clamps along it’s entire length. Like a corset for the hollow tube. This is a huge pain in the neck, but surprisingly effective in preventing rupture of the thin walls.
But I can understand why re-drilling was discouraged, Loren. I’ve had some longer stock blow apart during the attempt, and fling pieces of shattered wood. I’ve never been standing near enough to feel like I was in danger (my drilling rig obliges me to stand about five feet behind the stock in order to feed the drill), but if I were standing right over the turning stock I think this would be highly alarming! But re-drilling, as with re-reaming, is not really problematic if the wall thickness is sufficient.
I’m a little late to the party, but here’s my 2 cents.
I have a 9x20 JET metalworking lathe to make fittings, cut slides, and to turn the tube to just about the final OD. I do smooth things out with a straight chisel on the wood lathe and do just a bit of sanding.
The lathe weighs about 250 lb/110 kg. With me taking the motor end and my petite wife the bed end, we were able to lift it onto the table I made for it from 80/20. (The table was a great move. Pricey but does exactly what I need.)
I have a JET wood mini lathe with bed extension for ruffing and drilling. I don’t drill undersized as Loren suggests (although that would be better). I ruff very oversized once. I store the ruffed blanks in the garage and do a second ruffing and the first drilling in the summer, when it’s humid as all getout in the US Mid-Atlantic. I wet the inside of the bore at this point and store them in the basement. I do the second drilling in the winter when the humidity in our basement is in the 30% range. The bore is a tenth to a few tenths of a mm smaller at this point, so unless there’s a ridiculous warp, the second drilling straightens things out and burnishes the bore.
One suggestion: If you’re turning wood on the metalworking lathe, I’d recommend taking all the grease off the bed, the lead screw, and anything else that might get sawdust on it. (Definitely keep the parts inside the apron greased.) I use was on the exposed parts, which works just fine (be attentive to both the waxing and greasing) and wood chips don’t stick to it at all, and sawdust damn little. I always do a detailed cleaning to get rid of all sawdust when switching from wood to metalworking and make enough metal parts for 4-5 batches of whistles at once. Then another cleaning to get rid of all the cutting oil before switching back to wood.
This statement Geoffrey sent me off down a rabbit hole in the last few days! It does look a simple process once you have acquired a few key items. And it does seem to address some of the issues of timber seasoning referred to in this thread. I wonder if you have tried making an instrument from the combination of wood and epoxy resin I see in fancy knife handles etc. I can see some creative possibilities there and if we’re making instruments from Delrin then why not epoxy?
That’s a really good tip Charlie thanks. I can imagine wood shavings and sawdust don’t play too well with all of the moving parts of a metal working lathe. The good news is I also keep bees so I have lots of (too much!) beeswax on hand!
Why not, indeed. I learned from Geoffrey to coat the bore of my wooden flutes with epoxy to get a good tone out of them instead of having high energy loss to the not-very-dense hardwood (birch) that I was using. This is a low-maintenance alternative to using oil to fill up all the microscopic air pockets and make the wood behave as if it’s denser. I then took this a stage further by experimenting with flutes (Andean ones) made solely out of epoxy (a brand called Craft Resin which is food-safe). They sink in water as they have the density of tropical hardwood, but it’s only really the rigidity of a thin layer of the bore that counts for creating good tone.
If you want to make great instruments at low cost with minimal tooling, resin is a good way to do it. I actually made one quenilla (Andean flute in high C) using just an 8cm silicone bore mould rotated by a motor (8 revolutions per minute), taking five goes to get the instrument up to length by pouring liquid resin onto it and keeping the motor running for eight hours until it set hard, then the next day I’d move it along the mould with only 1cm of it left on it and add another 6cm onto the end of that. From then on I was able to rotate the resulting 30cm tube on its own to fatten it up with more layers of resin. I normally use a full length bore mould though - the short one was just a fun experiment using up some old silicone rubber solution while I was waiting for a deal price on another batch.
Flutes that look like glass are not attractive once they’re full of condensation, so I now embed holographic film under the surface, or mirror foil with alcohol ink in the next layer of resin on top to give them a metallic look, but it takes a lot of work to discover ways of doing this neatly, not least because there can be delamination issues due to epoxy not bonding well to such films, so when you drill holes through them you can get ugly air patches spreading around them. I’m going to experiment with metallic silver paint next as an alternative to mirror foil, but you can get foil to work, and I want to give ESR mirror film a go as it reflects 99% of the light that hits it instead of the more normal 70%, but it’s extremely expensive.
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. And patience. Not for the faint of heart, however.