Arch Top Mando Cello conversion

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Greg Steil
Posts: 158
Joined: Sat Jan 07, 2012 7:54 pm

Arch Top Mando Cello conversion

Post by Greg Steil »

I am finally getting close to finishing a project that has been hanging around for way too long. It is an old Silvertone(Harmony) N-10 arch top on which I plugged the tuner holes, added an overlay and then recut the headstock to the "Snakehead" shape. Will just be using regular Mando tuners. I also took off the fingerboard because it was loose, and inlayed a steel bar. Since the fingerboard is Maple, I have to "ebonize" it, so Stew Mac stain for that. How can I get a more Ebonyish look to this? I have not re-fretted yet. What would I do to get that? The neck will be sprayed with Black Lacquer and maybe a clear coat. Tailpiece? Probably just use the six string one and double up on two slots. Bridge? Not sure yet. Thinking about stringing like a 12 string with Octave strings. Anyone else done this?
Clay Schaeffer
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Joined: Fri Jan 06, 2012 12:04 pm

Re: Arch Top Mando Cello conversion

Post by Clay Schaeffer »

" How can I get a more Ebonyish look to this"

Replace it with a dark wood rather than ebonize the maple.

" Thinking about stringing like a 12 string with Octave strings"

I do that with double strung tenor guitars that I build.
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Steve Sawyer
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Joined: Wed Jan 02, 2013 2:20 pm
Location: Detroit, Michigan

Re: Arch Top Mando Cello conversion

Post by Steve Sawyer »

I just did some experimentation with ebonizing alder. It came out a deep, coal-black, and it's a color that actually forms in the wood, so it might be a good choice for a fingerboard.

Get a pad of 0000 steel wool, and wash thoroughly with dish soap and rinse thoroughly. Squeeze it dry in some paper towels and shred it. Put it in a jar (hopefully slightly larger than a quart) and fill with a quart of white vinegar. Leave the lid loose as the reaction will create a bit of hydrogen gas (not enough to be a danger) but it needs to escape. This will also create bubbles that will expand the volume, so don't fill the jar to the top unless you set it in some kind of glass plate or dish to catch it when it overflows a bit.

Let this sit for 5 days or so, then strain through a coffee filter. This is now a solution that contains iron.

Make up a "tea" solution of quebracho bark (available from any leather tanning supply - Amazon has it. This forms a solution high in tannin that will react with the iron to become black. Highly tannic woods like oak don't require the quebracho bark tea, but using the tea will ensure very consistent results, even on oak.

Wash the wood liberally with the quebracho bark tea and allow to dry. Brush on the vinegar/iron solution, and watch it slowly turn black. Let dry, lightly sand, then repeat the process.

Ebony, inky, coal-black is what you get. I'm going to use this I think on my next build to color the sides and backs of a body that will be veneered and bound.
==Steve==
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Jim McConkey
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Joined: Thu Jan 05, 2012 4:00 pm
Location: Way north of Baltimore, MD

Re: Arch Top Mando Cello conversion

Post by Jim McConkey »

Another readily available option is black fingerboard stain (StewMac, International Violin, etc.), which is a specialized version of India ink made specifically for the purpose of making fretboards very black. It is commonly used to make non-uniformly black ebony and even rosewood solid black, but a few years back I used it on a maple violin bridge (see my avatar) and it is still as black as the other violin hardware.
MIMForum Staff - Way North of Baltimore
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Beate Ritzert
Posts: 599
Joined: Thu Aug 02, 2012 8:20 am
Location: Germany

Re: Arch Top Mando Cello conversion

Post by Beate Ritzert »

Steve Sawyer wrote: Ebony, inky, coal-black is what you get. I'm going to use this I think on my next build to color the sides and backs of a body that will be veneered and bound.
But like any other wood stain the color will not go very deep, so You have to be careful sanding it...
Greg Steil
Posts: 158
Joined: Sat Jan 07, 2012 7:54 pm

Re: Arch Top Mando Cello conversion

Post by Greg Steil »

thanks for all the suggestions folks, however replacing the fingerboard is not in the picture for this beast, mostly just an experiment anyway.
Joshua Levin-Epstein
Posts: 243
Joined: Sun Jan 08, 2012 7:58 am
Location: Massachusetts

Re: Arch Top Mando Cello conversion

Post by Joshua Levin-Epstein »

Unless you've already drilled the holes, I would suggest using guitar machines rather than mandolin machines. You might even need to drill out a guitar machine to accept that low "C".
Mark Wybierala
Posts: 469
Joined: Fri Feb 03, 2012 10:14 am
Location: Central New Jersey

Re: Arch Top Mando Cello conversion

Post by Mark Wybierala »

I'm really into octave mandolins right now. My tailpieces involve taking an off the shelf trapeze tailpiece, removing the original string anchor cross-piece and replacing it with a length of 3/8" aluminum rod drilled for 8 string holes. McMasterCarr has the aluminum rod. Its an easy fabrication. You can polish up the aluminum rod to a mirror. Allparts sells both a long and short version of this tailpiece. I'll post a picture if I can get my camera working again.
Mark Wybierala
Posts: 469
Joined: Fri Feb 03, 2012 10:14 am
Location: Central New Jersey

Re: Arch Top Mando Cello conversion

Post by Mark Wybierala »

Eager to hear if you've done anything. Since the last post, we had someone come into the shop with a hand full of neglected/abandoned guitars to sell. One of them was a Taylor Big Baby that had been left in a wet basement. It was a mess with the top separating, evidence of mouses living in it and splotches of latex paint and mud. I was delighted to get it and immediately thought of an octave mando conversion. I unbolted the neck, narrowed the neck at the nut end, plugged the 5th and 2nd string tuner holes, and redrilled for a set of eight economy tuners. Installed a new nut. I cleaned up the body just a little and repaired the top separation with little effort. On the bridge, I tapered the 2nd 3rd 4th and 5th string holes and plugged them with old rosewood violin pegs and drilled holes to make eight string holes. Basically done. Its way cool. The intonation is a little off. I like to split the octave of the 3rd and 4th pairs. A crack on the top has developed - probably from the top drying out that I may or may not repair.
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