Building a Solid Wood Drum
Drum by meinl_aa
Drum by digidrums
You almost never see one of these but they are the holy grail of drum shells. They are made from a tree trunk which is
hollowed out and made into the shape of a drum - so there is no joint of any kind, and therefore, no glue. The picture
on the left shows a unique attempt to get many sizes of shells from one tree trunk.
Begin with a large piece of a tree trunk and hollow it. Paint the cut ends so that it dries evenly and doesn't crack. Store or kiln dry until the proper moisture content is achieved, then lathe inside and outside into finished shape.
The wood is in its natural state - there is no pressure on it to change or come out of round.
There are no joints or glue needed.
Hard to find suitable wood. Trees need to be very large and pieces have to remain uncracked during the drying process.
Because few people use this method, there is little information on how to do it.
Requires more special tools than the ply method.
Not a good method for making a thinner shell.
Special tools required:
Router for bearing edges.
Some creative method of hollowing them out.
Lathe for rounding. (Or special jig can be made with a router - see Koko's Stave Drum Without a Lathe sticky post in the General Building section of the Drum Shed forum.)
I've read where wood stabilizers are used by woodworkers who make art and craft type projects. Those stabilizers might also be helpful in drum buildling. I haven't tested them for this purpose, but Pentacryl looks ideal for wood prep for a solid shell.
Pentacryl is for keeping green wood from cracking while drying.
DISCUSSIONS FROM THE DRUMSHED FORUM
...from what I read, you cut out a rough block out of the "green" wood and then let it dry for a while before working on it. In my case, could I just start working directly on a log that has been drying for over 10 years? (Providing I find some that haven't cracked.)
The logs in your barn are stable in their current form, but as you cut them up into blanks, the wood will move again as you release its inner stresses. As you form the shell, the wood will move yet again as it tries to find its next level of stability. Some of wood-working is simply down time, waiting for the wood to adjust to its new form.
I don't have a lathe, but I guess with some time I could build a rig. Would a rig like Koko's work on a solid shell as well as on a stave?
Koko's rig is certainly a great place to start. I also have a rig that turns both the inside and outside of a drum shell. Please search on this forum for New Drum Turning Rig and New Drum Turning Rig Rev 2. While the end result is the same between my rig and Koko's (a finished shell), the rig designs are different. You can determine which matches your method of work, or if you'd rather buy a dedicated lathe.
My sense is you will want a dedicated lathe for its mass and motor's power, and you'll want a head stock that swings 90 degrees from the lathe's bed so that you can turn the face of a 14-15" diameter wood block. The lathe will need to be capable of some slow speeds - spinning an unbalanced 10 pound wood block at high RPMs sounds like a train wreck at the county fair.
An alternative to a lathe might be to rig a router onto a circle cutting jig, and using progressively longer router bits, cut halfway down into the log blank to roughly form the outside and inside dimensions. Flip the blank and repeat. This should give you 1-2 rough shells, which can be more easily worked on my or Koko's rig.
I found some "bowl blanks" on ebay....do you think these would be suitable to a snare application?
I don't know about those billets, mate. If they are really dry .... maybe, on a good day. For turning solids one of the biggest things is consistency in your wood, and those pieces look like they have blood lines and stuff going all over the place. Also the direction of the grain would not help your strength and ease of turning much at all - shell strength being the most important obviously. If I was where you're at now I would start researching different timber that is cut in your area. One of the biggest misconceptions about turning solid shells is that the timber has to be super hard... this isn't the case. What you need to look for in timber for solid shells is this:
- Very dense/consistent grain structure
- Reasonably low moisture content to begin with.
- And most important of all, very low shrinkage when drying.
All of these factors can be tweaked a bit and there are ways around everything if you're motivated enough (and have 3 years to watch something dry)(or can blow a heap of cash on a kiln).
Brecn77 can you give us a few examples of common wood types that meet your criteria - just in case I get lucky and find a tree that has been taken down.
Breckn77: Don't get caught thinking that hardwoods are the only way to go. I used to think that was the case because the shrinkage was less. But I have been having success with some really soft species, but still need a dense grain structure. If you have somewhere to throw some billets of timber for a few months, throw a heap of paint on the ends and leave it for 6-12 months and then give it a try. Not a good thing that you got so many trees down around you, but possibly good for your drums.
So the answer is - any timber that suits the criteria... You wont know how it will sound until it's together, but that's half the fun, isn't it?
I think, regardless of the thickness, incorporating face grain and end grain into a drum shell can be risky. For decorative bowls or hollow forms, or pretty much anything that's not being used as a structured sizeable-ing it to function properly (especially when mechanical parts are involved...lugs, hoops, tension rods...etc) it would turn out fine. People actually prefer it, it would give the bowl or piece character, it would warp and bend and take on its own shape during the drying process. I use these exotic blanks all the time, they might say that they're dried, but do not believe them. Certainly not if the piece of wood looks as good as that, if it were dry it would have tons of checks and cracks in it, and a dead give away is that end grain wax they put on there to keep it from loosing its moisture while in the store, when people see a bunch of cracks, checks and the blank being all warped they don't want to buy it.
You could, however, buy a blank, turn it roughly to it final size, like if it were a 5x14 snare turn it to 14.5 5.5, and for thickness if you were shooting for 3/4 turn it to 1.25 or so...... THEN apply an end grain wax, but use sparingly. You want the wood to dry but not too fast. The faster it dries the more the wood will crack. You would have to let the wood air out for a couple months with the wax on it. When you turn it to that size it will allow the wood to dry faster then usual, but safely. A moisture meter would come in handy to check if its ready, 6%-8% sounds about right, that's as dry as wood gets. It has to hold some moisture for it to stay rigid Ð a couple months should do. After that, it will take its form hopefully without any cracks. It will be all warped and out of round, but that's what the extra material's for. Mount it up then turn it to final diameter.
But then you are back to the stability of the shell - with all sides of grain exposed, you're left with a very delicate shell. With a stave glue up, the glue joints are the side grain of the wood. It would be like gluing half the staves with side grain joints and the other half with end grain joints, and we all know you can't glue end grain unless properly biscuit jointed, or pegged, which wouldn't work on a drum.
You can definitely make one of these, and assemble it, very carefully. It wouldn't be so much functional as it would be a piece of art, or a trophy snare that was mounted on the wall - which would be very cool and quite an accomplishment. And if you do, please post picture on here. Sorry if I killed your hopes on this snare......
breckn77: I agree that you will have heaps of trouble if you are turning a shell with end grain on it side. If you are going to do it, end grain must be on the bearing edges. It's a must. A bowl maybe not, a drum certainly. But in saying that, when heads are on the drum and all tensioned up... hmmm it would still be strong.
Dironian (to breckn77):
What do you seal the logs with exactly?
Here in Australia we call it end sealer, but ten coats of oil paint will do. Then put it in a plastic bag for about year or so.
Do you seal up the end grain just after you hack the tree into logs?
Yes as soon as you hack, then seal, then bag, then wait. You need to get the MC down to around 14% then it's in the zone of being seasoned and safe for the final turn.
Hmmm... that's different than me... I don't bag anything.. and 14% I would still think was too high, depends on the type of timber. Anyway... if it works for you, cool!
The reason I put my logs in the bag, because I had so much cracking when I was drying the logs. Un-dried wood moisture content normally begins at 50%. Jarrah wood is too unstable, well I'm in Sydney and over here the moisture content on average is 50% so it would be very hard to get it down to 6% without cracking. So I'm trying to slow it down. But I'm always experimenting, so I try the AC drying now because the MC is around 16%, so I'll see what happens. I Have moisture content meter. I'll let you guys know.
A fellow at a wood mill with a lot of experience gave me the following information. I don't know if it's true or not, I'm just passing it along.
6% moisture is the desired content. In the area where I live 12% is average (when it's not raining). Your area will vary. A house that is heated and air-conditioned will act as a kiln if you have the patience. Wood will lose moisture 1/2% per month in a typical house. That means that I would need to keep the wood on hand for a year to dry the wood. Not a fast way to go, but a cheap alternative to kiln drying.
This is pretty true....most guitar builders usually have wood out drying for years before they ever touch it.
Yea I think you have nearly got it, that would make sense if you were drying planks and common sizes but...the only thing is that wood doesn't loose moisture from the inside out but from where it is in contact with the atmosphere. Everything timber is different, but a rule of thumb is an inch a year. In the case of a 14" billet, that means, by my calculations ..... A very long time...
The way I get around this is to rough machine the shells to a thickness of about an inch or something around that, and then leave that to dry for 6 months to a year and that works for me. There are some other good things you need to do though, and one is as soon as you have rough machined the shell, seal the ends with something. Sealer, paint, varnish, salad dressing, whatever...Well maybe not the last one. If it's going to crack, that is where it will happen. Doing this helps it dry from the inside out and not crack the ends.
This will not work with all timbers but 8 times out of 10 timbers will be unsuitable for solid shells done this way (or probably any way). I'm just letting you know what has worked for me and what hasn't. I have tried loads, yea and I mean LOADS of different species and found that selecting the right one is the most important thing. And each variety makes you change how you do the whole process. And then you may find a variety that stay's together, looks great ,dry's well, is available near you, won't cost the earth...BUT you also need to find out if it sounds good at that is the main thing!!
Well I'm looking to finally finish the solid snare drum. It's been two and an half years in the making. Drying out the log has been a long journey. I did leave a good amount of wood, but it's shrunk so much in the diameter.
How can I cut many sizes from one log?
How about looking for a waterjet cutter (company) and let them do the cutting?
.:On The Rock:
A waterjet wouldn't be able to go anywhere near that thick I think. Possibly CNC lasers?
For information on where to purchase of solid shells, see the Supplier's page on this site.