My Side Bending Pipes

I just finished construction of my second pipe, a little one incher, and thought I'd share the jerry rigged little contraption with you, along with my simpler, less "rigged" first pipe, a three incher. Both pipes are one foot long. The larger of the two started as a hunk of aluminum pipe I bought online. I needed a way to suspend it above the bench for bending purposes, so I talked to my ever helpful neighbor about it, and he said he knows a guy who welds aluminum, said he'd ask him, and he took the pipe with him when he left. Month later I had a pro looking rig, and nobody will take my money, so it was cheap. It's heated with a 100 watt bulb, the largest I could fit in there, and it takes a good 45 minutes to reach peak heat, but it works well, except I was dismayed to discover I can't bend the tight waist my form requires on a three inch pipe, hence the creation of the 1 inch bending pipe. I acquired the parts for that over time. It's heated by a 1200 watt, 1 inch diameter, 6 inch long heating cartridge, smeared with heat sync compound to give it a snug fit, and wired to a sliding dimmer switch (a setup approved by the manufacturer). I cobbled the fixture for the pipe out of some left over pine and some L and U brackets. You can see it in the pics. The cloth strips are from an automotive store, and are good for up to 1500 F. Originally, Nu Uke, sent me some old asbestos apron strips to use, but I got nervous about the fiber on the ragged edges coming loose and air born over time, so I sealed the edges with super glue, but then when I fired up the pipe, the glue smoked, so I replaced it with the aforementioned strips from the automotive store. Two Dogs Plucking pointed that product out, and I was lucky to walk into an automotive store that happened to sell it by the foot. Thanks to both Nu Uke and Two Dogs Plucking. The little bender works great, and can get hot enough to scorch wood with the dimmer set to 50%. Yes, I did spend too much to build it, but I spent it over time, so it didn't hurt too badly. Anyway, some pics:



I bent up some cherry sides today that fit my form perfectly, which is a first for me.

Glad to hear you're back in the shop and that the finger is doing well. Love that little one incher. What sort of heating cartridge did you use?

Matt, thanks for this post. I have not bent any wood yet, but will soon.
Watched a video of a bending process the other day that used a form and a heating blanket.
As the wet wood is heated it's drawn into the form and clamped.... am sure your familiar with the process.
My unexperienced question is, what are the pros and cons of the two different methods?

two dogs plucking said:

Glad to hear you're back in the shop and that the finger is doing well.

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I'll second that. Good to see the feisty fighter back in the ring!

I like your setup, Matt. Some day maybe you can bend the bouts on the three incher while ??? (hm, someone I'm thinking of) does the waists on the one incher. Half the work and twice the fun

two dogs plucking said:

Glad to hear you're back in the shop and that the finger is doing well. Love that little one incher. What sort of heating cartridge did you use?

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It's aching pretty good right now--have to give it a rest for a few days. The heater cartridges are called just that, heater cartridges. Found mine at grainger.com, but I didn't like their price, so I shopped around and ordered it somewhere else for $5 less, only to find the package arrived shipped from grainger. They have to be in contact with the sides, hence the need for the heat sink paste. Also, 1 inch is as big as they make, so bigger pipes heated in this fashion might be problematic. But, it really kicks out the heat, Maybe a thicker walled, specialty milled pipe would work. It would take longer to heat up, but a little cold wet wood wouldn't dampen its temps much.

fahrner said:

Matt, thanks for this post. I have not bent any wood yet, but will soon.
Watched a video of a bending process the other day that used a form and a heating blanket.
As the wet wood is heated it's drawn into the form and clamped.... am sure your familiar with the process.
My unexperienced question is, what are the pros and cons of the two different methods?

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Pros of the Fox style bender (named after Charles Fox): repeatability. You can crank out whatever shape you have a mold built for, and bindings and solid linings in that shape, too. That must be nice. Cons: it's not hands on, and you can't really see or feel what's happening to the wood as its being bent. Learning is trial and error, and this machine makes you adjust your process deductively through examination of the results--if that makes any sense. People do just fine with them, and someday that'll be the way I do it, too. Another con: they cost many times more to build one (unless you're Timbuck) than to throw together a light bulb driven piece of pipe.

Pros of the bending iron: it's cheap! It works great! When you've got your temps right you can feel that water instantly evaporate, and you know you've got your bend on. It's very tactile and it feels great--very satisfying.

Cons: good luck bending the linings and binding to match those sides! You can do it, but it's another level of skill.

Made perfect sense Matt. Thank you.

Lookin good Matt!
Understand about the asbestos fiber. I used mine firmly clamped behind my big five inch pipe flange so no worry about flying fibers, I hope. Funny, I considered sealing the cut edges too, but figured it might burn or smoke or something! Can't wait to hear how the pipes work and ...how your strumming technique has improved with your newly modified strumming hand. :>

I have a question. How thick does the sides of the ukes have to be? I've heard that if they are to thin, the pipe will burn through it.
Also what can you use to heat the tube?

Yep; as other said, welcome back Matt. My dad always said, "When you get bucked off, you have to get back in the saddle and ride". Take it easy for awhile though. No reinjuries!

I was happy to see a thread on bending sides pop up. I've bent my first sides in 6 years recently with the side bending jig I made back then and I honestly don't remember having these problems before. I am bending kiln dried mahogany instead of air dried koa or mango, so wondered if that was why I was having break-outs in the tight bends. I can tell the mahogany is brittle compared with the woods I'm used to, but I'm back to trial and error. I've never used a bending pipe; will have to go online looking for lessons in bending.

Happy healing.

Welcome back Matt, GREAT to know you're condition it improving!

That being said, another few noob questions: how much water should one use before heating it up to bend it, as well as what purpose does the water serve? lastly, is there such a thing as too much water? if so, what could happen if one uses too much?

As you know, I'm new to this, but here's my take on it: the water only serves to transport the heat into the wood. You could (and some do) do it without water. That was my attitude going into it; unfortunately, my pipe, heated by a 100 watt bulb, doesn't get hot enough for that, or perhaps I just don't have the patience. The first sides I bent were walnut, and I chose walnut because it has a reputation of being easy to bend. I figured, since some people don't use water, and walnut is easy to bend, I won't use water when I bend my walnut. Suffice it to say, it didn't readily bend, so I submerged the walnut sides for 15 minutes, and then they bent just easy as can be. I've since learned my pipe needs a good 45 minutes (to an hour) to heat up properly, so that 15 minutes undoubtedly helped in that regard, too, but the water does make a big difference. How much water? I'd say, based on my experiences bending walnut and cherry, anything from spritzing them to soaking them for 15 minutes will be just fine. I reason that by soaking them you get water into the pores, and so extend the amount of steam you can generate. After that's gone, though, I just spritz them. Could one use too much water? I don't think so. I understand some people boil their sides immediately before bending. I've seen youtube vids of it. I can't imagine it's necessary, and I understand it can mess with the look of some woods. Someone here once said it left their koa looking muddy.

Matt Clara said:

...Could one use too much water? I don't think so. I understand some people boil their sides immediately before bending. I've seen youtube vids of it. I can't imagine it's necessary, and I understand it can mess with the look of some woods. Someone here once said it left their koa looking muddy.

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Careful with figured wood. According to some sources including the StewMac bending instructions, soaking can damage highly figured woods like curly koa and maple.

The grain on figured wood doesn’t run the length of the piece, but runs alternately up and down through it. Over-wetting this wood can cause the grain fibers to separate from each other, which results in fractures.

erich@muttcrew.net said:

Careful with figured wood. According to some sources including the StewMac bending instructions, soaking can damage highly figured woods like curly koa and maple.

The grain on figured wood doesn’t run the length of the piece, but runs alternately up and down through it. Over-wetting this wood can cause the grain fibers to separate from each other, which results in fractures.

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That's a great link, Erich--I hadn't seen it before.

erich@muttcrew.net said:

Careful with figured wood. According to some sources including the StewMac bending instructions, soaking can damage highly figured woods like curly koa and maple.

The grain on figured wood doesn’t run the length of the piece, but runs alternately up and down through it. Over-wetting this wood can cause the grain fibers to separate from each other, which results in fractures.

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thanks Erich, like matt, I didn't know about that link. Just wondering, would lacewood be considered "figured" wood? or would it go into the "straight grained" catagory?