MIMF

Due to an inspiration from a very recent post I'm making a dulcimer. Mostly curly maple but the top is Spanish cedar. Except for the top, everything else is coming out of a fairly nice 5/4 plank of curly maple. I've bent sides for a guitar using a fox bender but I'm going to be roughing it for the dulcimer. I saw a youtube video of someone steaming maple using a hotplate and a length of 8" galvanized ducting about 3 ft long. He just put water in a 4qt pan, put the 8" ducting upright in the pan, and hung the sides in the ducting hanging from a cap. 10 to 15 minutes in the steamer from a boil??? This seem simple enough. I've built a two-part full width form to achieve the curves. I also have a heated bending block if I need back up but I've never used it before. I anticipate a little complication from the busy-ness of the maple gain pattern.

What is a good thickness for curly maple sides? My thickness planer is getting a bit of tear-out from the curly... I have a mill nearby with a thickness sander that can very nicely thin these to size for a dozen donuts. I'm thinkin' 1 3/4 tall sides.

I have never personally used a steam box to bend sides but have read post warning against it. The most compelling reason seems applicable in your case, curly wood. . . soaking in steam can introdouce too much moisture making the figure (which is just severe localized runnout) "delaminate." That said, dulcimer sides don't have super tight curves. If you have already made the forms, why not just fit them in the bender and use your blanket?

Edit:

Keep in mind, this is not first hand experience. If someone comes along who has done this and has a technique, listen to them not me.

Thanks Bryan, My forms are only intended to shape the steam softened wood. I've made an inner and an outer that'll take up to a 2" tall side for the hour-glass curved shape. The curves are generally those that I traced from an acoustic guitar and then extended. They're not very tight. Even bent to the desired shape, they'll still fit in an 8" diameter ducting pipe so I can steam multiple times if I need to. If the curly maple gives me too much grief, its not a huge loss. I'll just buy some less excited maple. Still, I need a recommended thickness. Can I get away with 2mm? I'd like to stay on the thicker side if I can.

I didn't say it well but what I was (trying to) suggesting is that you use the forms you made and press them together with a side and your heat blanket between them similar to how the side bender would work.

I'm sure you could do 2mm or a little bit thicker. I usually shoot for between 0.08 and 0.085 inches (2.032 and 2.159 mm) for most side woods. thinner wouldn't be much of a problem either with the shallow sides and linings you won't have too much unsupported side anyway.

For the dulcimers I've built (probably 100+) I generally leave the sides about 1/8 inch thick but I don't use linings or bindings. Steam or hot water and curley wood is usually a bad mix. The sides may "kink" when you try to bend them. If you have a heat gun with an exposed nozzle you can use that as a bending iron. I like to make the sides about 2 1/2 to 3 inches deep. The deeper sound box seems to give a fuller sound.
I would use something besides Spanish cedar (cedro) for the soundboard. It seems a little "mushy" to me. Western red cedar or redwood makes a very good top and you can often find a good piece at the lumber yard.
One thing to keep in mind it to hollow out the underside of the fret box. Keeping weight off the soundboard as much as practical is a good thing. When the hollow fret box is glued to the top it forms a hollow box beam construction that helps support the top and keeps the fingerboard straight.
The first instrument I built was a dulcimer and I still make a few of them from time to time. They are fairly simple and fun to build and play.

Bryan, Sorry I wasn't clear. I've used a fox bender but I don't own one. Years ago I spent two weeks in a short course of acoustic guitar building. I bought a few boxes of violin making tools/supplies from a fella who tried to get into it and quit. Included in this was a bending iron. I'll play with it and see what I can do.

Clay, Thanks for the information. I'm just jumping into this feet first. An instrument will arise and tone will happen one way or another. As far as the top is concerned, I was told that the plank I purchased was mahogany at the mill but I'm getting that icky taste in my mouth when I'm making sawdust which leads me to believe it is Spanish Cedar. I can't blame the mill because after I selected my maple, I went to their scrap bin and found this plank which was just the perfect size to get a dulcimer top. The curly maple was a mistake on my part. The whole point of this was to make my first dulcimer and acoustic instrument from scratch at home. I should have known better and stayed focused. I'm watching a lot of youtube for bending sides. I really appreciate the tip concerning the underside of the neck and what you say makes sense. I'm still not totally enlightened to why a dulcimer works. I don't fully appreciate why the bridge is not in contact with the soundboard/top. I was guessing that it is the entire neck that transfers the tone to the top and your comments reinforce that idea. Regardless, I'm going to end up with a stick with strings attached to a wooden box of some sort. This is an adventure.

Ah, I see now. Sorry for my confusion. Since you have a bending iron already, I suggest you do some practice runs with it instead of trying steam. Curly maple can be a challenge to bend but with some practice (and maybe some backup sideds on hand) you should be able to bend a set of dulcimer sides.

Going to the mill today with donuts to see if they'll thickness-sand my sides. This is awesome fun and such an adventure. I'm building from the seat of my pants and I think I've just figured something out. The neck can be light because in most designs, the headstock is a separate structure and the string tension is not applied directly to the neck in a manner that would distort the neck as it does on a guitar. The rotational force and pull on the headstock from the strings is applied to the body while the neck is almost free to float with the vibration of the top. I was going to take a short cut and build a one piece neck and headstock. Do builders ever totally separate the headstock from the neck?

I know what you mean about the fun you are having. My very first instrument was a long necked dulcimer (meant to be held and played like a strumstick). It was very much a seat of the pants effort. It was my very first woodworking project. In fact, it was not originally intended to be put together. I was just practicing with the tools I bought (didn't even know I needed to sharpen them first). I was just trying to figure out how to accomplish the steps I thought would go into the instrument but I ended up assembling and stringing my practice wood.

I was blown away by the fact that I made something that played and played in tune. Looking back, it was very quiet and not particularly nice sounding but I loved it. I can't overstate how overbuilt it is. This all happened before i really started reading here. I was just making things up as I went along based on having seen a picture of a long neck dulcimer online once. Good times.

My focus for nearly 20 years has been electric guitars and fretwork and my claim to be a luthier is thin with the majority of my efforts and time spent being a tech. There is so much talent and fine skill to admire on this forum. I'm finding that there is a lot more to a simple dulcimer than appears to the eye. I enjoy building without plans but my walls are covered with quite a few bad ideas. I really should buy some plans some day for a dose of discipline.

Well I bought a dozen assorted donuts and 4 coffees and went to the mill to use the thickness sander as I have many times before. They were closed so they folks at my shop are gonna eat donuts.

Does anyone know how to significantly reduce tearout on a thickness planer? I have a 12.5" 3-blade Dewalt of the typical home Depot quality. I have the sides down to a little less than 1/4" thick but there is a small amount of tearout. My machine is in good shape but I think I'm asking too much from it with the curly maple. I thought is was worth asking anyway

I have no advice for getting more from your planer since I have never used one. The sides you want to thickness are very narrow so there may be other ways. What do you have at your disposal. A hand plane with a toothed blade, or a scraper plane may be an options. If you have a spindle sander or drill press with a sanding drum you could probably rig up something similar to the "luthier's friend." Google will show you what that looks like. You could even rig something similar with a belt sander.

"Does anyone know how to significantly reduce tearout on a thickness planer?"

On curly wood? Yes- don't use it. Patience is a virtue. Another day and another box of donuts might be the better option.

Mountain dulcimers are technically classified as zithers, and like zithers often have the saddle located over an end block. This tends to make them a little quiet. Some of us build them with the saddle located further in and on the soundboard. This can make them significantly louder, which is not a bad thing. If you look at the dulcimer Dale built and linked to in his post you will see about how far off the endblock many of us place the saddle. Also if you go with the teardrop shape he used you don't really need to "bend" the sides - by using a couple of sticks as "spreaders" and gluing in the endblocks and then gluing on the back you can form the shape without a mold. I helped my boys' scout troop build dulcimers using this method.
Curly maple will make a beautiful instrument, and with careful work, I'm sure you will do fine with it. I built my first instrument (dulcimer) with curly walnut and a WRC top.

You guys have been great. I'm not beyond the point of no return to go with a tear drop shape. I could at least make use of this holiday time off and then go back with my donuts when the crew at the mill is working. I think I have enough wood for two instruments. I have a 36" belt sander that I feel perky enough to try using to thin the sides a bit. I need to clear the few tear-outs anyway. Just be patient, use my calipers and make some saw dust.

On figured wood I try to make and keep one side perfect - no tear outs. The inside can have small tear outs or imperfections that won't be seen in the finished instrument.
A hand plane with a toothed blade and then using a sharp scraper might be another way to thickness the plates. If you have a spare plane blade you can tooth it with a dremel tool.
If you use a belt sander use a coarse grit belt and then follow that with a scraper. You can use the beltsander in the same fashion as demonstrated for the toothed plane.

www.youtube.com/watch?v=Gl8Tj1lUha4

Excellent. I've never encountered a toothed plane and it really makes sense. Planes are something that I do not have with the exception of a few good quality finger planes. I could use a few tools but I need to justify the purchase. I've made fair progress with the belt sander. Very nearly took off the tips of my left hand fingers a few times as a new 80 grit belt really bites and I need to play bass on Saturday. Inattention and oops -- looking for blood -- no blood -- we're okay New day today. Slow down. Purposeful attention to detail. I think maybe I might be able to glue something together before the sun goes down.

Hi Mark,
Belt sanders, although not the most dangerous tool, can cause you a lot of grief. The most "maiming" injury I have had was from a belt sander. It sucked my finger into the machine and ground the end of it off in just a few seconds. The trigger was locked on and there was no way for me to pull my finger out. Luckily there was a fast thinking person near by who pulled the plug. It is a bit shorter now and causes me to miss the string sometimes when I finger pick the guitar strings.
Most of the planes I have are flea market finds. Often you can find a nice old #4 or 5 Stanley under $10. I think the most I've paid was $35 for a #7 jointer plane. Sargent is another good make as is Millers Falls. You can order extra plane blades for whatever plane you find and modify them to allow the plane to become a scrub plane or toothing plane by swapping the blade and adjusting the frog to change the throat opening (if necessary). Sometimes you can find a plane for less than the price of a new blade (which aren't expensive) and keep it set up for a specific task.
I don't use planes as often as I could, but for some tasks it is quicker to grab a hand plane and "do it" than to set up a machine.

I shoot for .010-.012 on my dulcimer sides. The curly maple should bend fairly easily on your bending iron. Practice on some scrap wood. Tho I have never used Spanish Cedar, I think you will have a nice sounding instrument.

Belt sander has never sent me to the ER but certainly has removed a couple of square inches of skin in the last twenty years. The $99 combo belt sanders from Lowes and Home Depot do a lot of things they aren't really designed for. My trip to the ER was a typical encounter with a table saw doing things that I shouldn't so now I don't do those things. However the lesson that really stands out is that no matter how vulgar the words are or how loud you yell them, they do absolutely nothing for pain. Searching for the right words and reaching back to those you haven't said since whispering them on a 3rd grade playground, its a silly epiphany to realize how useless dirty words are.

I need to confess that I've only seen a dulcimer first hand once. It was brought to the shop to have its violin-style tuning pegs adjusted to no longer slip. I should have spent a little more time with it. I was very lucky to have a beautiful woman ask to see it and she played it. I was very impressed with the tone although I'm sure it was the woman's presence and voice that made the moment so memorable.

I have the sides down to 1.25. Lots of sawdust. I could have easily used the thickness planer to get a lot closer to the end goal. I also have the back halves glued together. Gonna try the bender today at the shop.

Dale, either you misplaced a decimal point or your dulcimers are the lightest built instruments in the world.