Questions about building a squareneck style resonator out of a tool box

Hey everyone. I recently picked a really cool old metal tool box that is large enough to hold a full size biscuit cone and I intend to build a six string "dobro" out of it. I have a couple roundneck resos and I am pretty familiar with how they work, and I think as my first project this is quite doable. Its currently just in the planning stages but the two biggest things I am concerned about are the construction and attachment of the soundwell to the metal top of the box, and how I should attach the squareneck to the box itself. I know that a neck through design would be simpler but I don't think after the cone is installed there will be enough room in the box for a neck through design/ I want to get as much of the metalic tone of the box itself as possible. Should a insert some kind of heel block in the end of the box where I am going to connect the neck and bolt it on? And as far is the soundwell is concerned, how should I go about constructing one? I was thinking about just gluing a bunch of pieces of wood together as a square, cutting a round hole in it, and then routing out a lip for the cone to sit on. My concern is how to connect it to the top of the box, I don't have much faith that just gluing it to the metal top of the box is gonna hold when strung up. Any advice or words of wisdom is greatly appreciated. I will post pics once I get going.

Hey

I tend to fly by the seat of my pants so keep this in mind as I throw my two cents in. I have built two cigar box guitars and while they aint pretty, they ended up being great instruments.

Both of them are resonators, one is single cone style and uses 64 volvo hubcap for the resonator, the other ( my favorite ) is a tricone made with resonators cut out of muffin tins. The tricone is amazing and if I play on my porch it can be heard across the street. Here is what my limited experience has taught me.

First , if you are planning on using a steel tool box for the body, then you have to think national guitars, not wood body dobros which have a much different sound. Dobros use a wooden soundwell which the resonator rests on, nations have a resonator that seats on a metal frame.

While most of the sound comes from the resonators, the body material of the instrument does make a difference. Go on to Nationals website and listen to a woodbody tricone and a metal body tricone. Big difference in sound. Think of your proposed cigar box as a steel body national. This means that you need to find a way to have your cone rest on a metal seat, and if you can work it so the metal seat has a strong contact with the body even better.

With my tricone I cut out the bottom of a cookie tin, with holes cut out leaving just enough room for the cones to seat and the sound to flow through. I used a glued bone bridge modeled after a national. ( why reinvent the wheel). Then I found that the metal seat had to suspended, as it was deadened and did not resonate when attached to the neck through. But I suspended it on dowels that attached it to the back of the body and raised it an 8^th of an inch above the neck thru. Glue and tiny screws through the metal seat, and tiny screws through the back into the dowels held everything firm. Two years later everything is still solid.

I also had to cut down the neck thru in the area where the metal seat was placed in order to fit it in and not have it touch the wood. It did not appear to weaken it as it is still solid.

The single cone was easier I simply found a brass serving plate that was a little bigger than the cone and cut it out the middle leaving just enough room for the cone to seat. The lip on the plate was raised so I cut the hole in the body just big enough to allow the raised lip of the plate to rest on the body. Then I glued it on. Each cigar box has different issues so my suggestions will need modification but you get the idea.

You will get a much better sound if the resonator is seated on metal, and it will get even better if the vibrations can also be transmitted to the body, as it is harmonics of all the vibrations that will give you a rich sound with overtones unique to your instrument.

Lastly open tunings put a lot of pressure on the neck so much that my single cone wants to separate from the where it is attached to the neck stick. I think long term problems will be avoided if you have the neck stick run the length of the box.

I think you have a great project, I was so impressed by the sound of the tricone I am going to have a luthier build me one with a metal box using tricones. I am not handy and my CG`s look a little frankenstinien, but I think someone who knew what their were doing could make one capable of competing with any commercial guitar resonator .

BTW I just joined this site, mostly to respond to your questions, because I think you will be blown away by the tonal quality of your CG, especially if you configure the resonator to sit on a metal seat.

Replies

atkinson traveler January 19, 2012 at 2:51pm

Hey

I tend to fly by the seat of my pants so keep this in mind as I throw my two cents in. I have built two cigar box guitars and while they aint pretty, they ended up being great instruments.

Both of them are resonators, one is single cone style and uses 64 volvo hubcap for the resonator, the other ( my favorite ) is a tricone made with resonators cut out of muffin tins. The tricone is amazing and if I play on my porch it can be heard across the street. Here is what my limited experience has taught me.

First , if you are planning on using a steel tool box for the body, then you have to think national guitars, not wood body dobros which have a much different sound. Dobros use a wooden soundwell which the resonator rests on, nations have a resonator that seats on a metal frame.

While most of the sound comes from the resonators, the body material of the instrument does make a difference. Go on to Nationals website and listen to a woodbody tricone and a metal body tricone. Big difference in sound. Think of your proposed cigar box as a steel body national. This means that you need to find a way to have your cone rest on a metal seat, and if you can work it so the metal seat has a strong contact with the body even better.

With my tricone I cut out the bottom of a cookie tin, with holes cut out leaving just enough room for the cones to seat and the sound to flow through. I used a glued bone bridge modeled after a national. ( why reinvent the wheel). Then I found that the metal seat had to suspended, as it was deadened and did not resonate when attached to the neck through. But I suspended it on dowels that attached it to the back of the body and raised it an 8^th of an inch above the neck thru. Glue and tiny screws through the metal seat, and tiny screws through the back into the dowels held everything firm. Two years later everything is still solid.

I also had to cut down the neck thru in the area where the metal seat was placed in order to fit it in and not have it touch the wood. It did not appear to weaken it as it is still solid.

The single cone was easier I simply found a brass serving plate that was a little bigger than the cone and cut it out the middle leaving just enough room for the cone to seat. The lip on the plate was raised so I cut the hole in the body just big enough to allow the raised lip of the plate to rest on the body. Then I glued it on. Each cigar box has different issues so my suggestions will need modification but you get the idea.

You will get a much better sound if the resonator is seated on metal, and it will get even better if the vibrations can also be transmitted to the body, as it is harmonics of all the vibrations that will give you a rich sound with overtones unique to your instrument.

Lastly open tunings put a lot of pressure on the neck so much that my single cone wants to separate from the where it is attached to the neck stick. I think long term problems will be avoided if you have the neck stick run the length of the box.

I think you have a great project, I was so impressed by the sound of the tricone I am going to have a luthier build me one with a metal box using tricones. I am not handy and my CG`s look a little frankenstinien, but I think someone who knew what their were doing could make one capable of competing with any commercial guitar resonator .

BTW I just joined this site, mostly to respond to your questions, because I think you will be blown away by the tonal quality of your CG, especially if you configure the resonator to sit on a metal seat.
The Phrygian Kid January 19, 2012 at 8:54am

For a first project just do a neck thru and save that cone. The tool box itself will probly make an awesome reso, I've had some great results from steel boxes.
ChickenboneJohn January 19, 2012 at 3:34am

I make soundwells from birch plywood and either rout the hole with a circle jig or cut them on the bandsaw, again with a homemade jig, then if necessary glue and stack them for the required depth.

Dobro (spider bridge) soundwells traditionally run full depth from the top to the back of the guitar, but more and more makers are using a shallow soundwell and propping it from front to back (I did this on my last 12 string reso). National style (biscuit bridge) soundwells are usually fixed to the underside of the top and then supported by the thru' neckstick, which is also propped thru' to the back.

You could epoxy the soundwell to the top and use some additional screws to make sure you get a good mechanical fixing. Make sure the steel is clean (I use clutch cleaner for de-greasing ) before glueing. I'd also prop the soundwell from front to back in some way.
Mungo Park January 18, 2012 at 10:43pm

You could attach the neck with a heel b;lock like in a regular guitar, only make the heel block bigger inside the box.

If you make a wooden sound well inside the box for the cone then drill some holes into it to let some of the sound come out into the box it's self. You do not have to connect it to the top of the box but you could screw through the top of the box and into the sound well to hold it firm to the top, or put a few block shims under the sound well so it just about touches the top by a hair, course this is not conventional but I have done it. Once you get the neck in and the sound well in you could connect the sound well to the neck by a piece of wood to help the neck vibrations come into the box and firm things up.

Cheers Ron.

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