Official Luthiers Forum!

Just about in the finish stage of my first Cocobolo dred and tapping on the back I noticed a really ringing taptone. I'm thinking that if I use the same for the top of the next one I could have a fine sounding guitar. The big drawback?...it's flatsawn. I have a guy that wants a guitar that when he takes it out of the case everybody in the room will say "WOW. What is that?" Maybe I'll color it orange with green poka dots.
I would like some professional input nonetheless. Thanks. Richard

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RJS

Not a pro, but...

Coco is pretty heavy stuff. I never liked the sound of mahogany tops, and that is much lighter and easier for the strings to get moving.

How about some wild bear claw spruce? Maybe veneer if you have to have the looks? How about a sunburst?

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Gabriel Regalbuto
Carlsbad, California
Freedom 35!

Way too heavy. You need stiff light wood for a top, like spruce.

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Jim Watts
http://jameswattsguitars.com

The defining characteristic of good soundboard lumber is stiffness/weight ratio - and rosewoods lose out bigtime to spruce and cedar. The soundboard generates sound by being driven into vibration by the vibrating strings, and by the time you thin them enough for the required strength, rosewoods (and almost all hardwoods) are just too heavy to be driven very well by the strings.

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The member formerly known as erikbojerik....

I'm with the crowd here, but, if it is for yourself, go ahead and give it a try. Worst case, you made a dud and learn a lot. Best case, you prove us all wrong.
I would make it with a bolt on neck so you can easily replace the top.
Make it as thin as you dare. If you build to a stiffness or a feel, make the coco the same feel or stiffness as the standard tops you have been making. If you get close to .065 "- .070" thick (thin?), and it seems light weight enough for the strings to move the top, you might be in luck, or you might not.
This experiment will sound crazy to some.

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"An adventure is only an inconvenience rightly considered. An inconvenience is an adventure wrongly considered." G. K. Chesterton.

too heavy.....

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Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com

Cocobolo for back and sides? Absolutely!

Cocobolo for a top? Absolutely not!

The wood is of a whole different set of characteristics than what is necessary and most desired for a
top on an acoustic guitar. It's weight in proportion to its stiffness is just to high to produce an environment
that will conducive to good tone.

It's all been tried by builders over the years and is not used regularly for good reasons.

Regards,
Kevin Gallagher/Omega Guitars

Thank you very much. Sure would look pretty though.

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RJS

I'm with Steve give it a go, if its for you, don't finish the guitar string it up and see how it sounds, then if you feel you can't live with the sound put a new top on. I'll even play devils advocate and say you don't have to be a sheep, Ukes have hardwood tops and nylon strings to power it and millions love them look at the current resurgence

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Formerly JJH

I learn more from my mistakes than my successes

If you have the time and money to waste, by all means, give it a try. We who have experienced the results
are just trying to save you some of both.

Koa is far from hardwood as it is used for tops on ukes. I've built many guitars with Koa tops and they've
all sounded great. The weight/stiffness ratio in Koa is within the realm that makes great tone and resonance
possible.

It has nothing to do with being sheep or not, but taking advantage of the experience of those who have
gone there before.

Regards,
Kevin Gallagher/Omega Guitars

Kevin no offence was meant, but have you made a cocobolo guitar? I'm guessing not, like you said it comes down to time and money, it may well turn out to be a mistake, but we learn more from our mistakes than our successes or I do. I'm a blacksmith who dabbles in knife-making too and have always been advised not to tread the paths I have because I'm wasting my time, and i've been pooh poohed for the way I do thing, yet at events I'm asked by other more experienced people to help them correct thing others would of thrown away as scrap. All I'm saying is that with out treading the path I have with the failures along the way I wouldn't be able help people the way I can.

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Formerly JJH

I learn more from my mistakes than my successes

John, seriously you've got to be kidding.

I want to build one with a concrete top. Of course it's a little heavy so I'm going to fill it with helium. Of course to stop the helium from escaping I won't have a soundhole. What does everyone think??? If anyone knocks this idea without having built one their criticisim is not valid.

Come on....

Richard, no offense to you. A coco top is not a good idea as has been explained. I've had lot's of ideas that weren't so good and I'm thankful when builders of this caliber take the time to explain why. The good advice I have received has helped me spend my time doing things I really learn from.

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David White, Toronto

"All my favourite singers can't sing."

Dave kidding no just trying to provoke a different line of thought, like I said in my knife making I followed my own path in the begining when making my pattern welded steels, I had a 50% failure rate compared with my 100% success rate using proper materials, but that journey now has ended up in my advice being sought in repairing and fixing dud billets where other may throw them away!

What I'm saying is it may lead to knowing how thin a hardwood top can be made, the vast damping cause of the heavy top may lead rise to a certain sound which may become known as the "Sutherland Sound" all very unlikely and most probably a waste of 10's of hours but all I'm saying is it may lead to altering a building method, creating more successful mahogany or spruce tops in his later builds.

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Formerly JJH

I learn more from my mistakes than my successes

John,
I completely agree. Richard would learn a lot and who knows what innovation may come out of it. If no one ever tried new things, we'd be stuck in tradition.

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"An adventure is only an inconvenience rightly considered. An inconvenience is an adventure wrongly considered." G. K. Chesterton.

Good point, however if you already know it's a mistake...

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Jeremy Douglas

Look at the density of the Cocobolo, more than twice that of spruce.
Are you going to thin that top down to 60 thou to compensate?
And then it is flatsawn.
A waste of timber and time.
I am not against hardwood tops, have built with tasmanian blackwood and am currently building an all honduras mahogany with very low density mahogany, but this cocobolo does not make sense.

If the guitar is being built to be "plugged in" and played it might work out O.K. Many dulcimers have hardwood tops, and while they are usually not as loud as softwood topped ones, they often have a quality of sound that is appealing.
That being said - cocobolo would not be my first choice for a hardwood top.

Well it's not as if no one has ever tried it - you can be certain that many have. It's just boring reading/writing when you get a negative result.

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The member formerly known as erikbojerik....

Thanks for the posts everyone. I am going to try a deflection comparison with some top spruce and see how thin it will be when I need to stop sanding. If I stop at a thickness that I think will hold then I'm gonna try it. For those who are concerned with the waste (cost if not used) I spent 240$ and got 1500$ worth out of the slab. So it won't hurt too much.
It'll be a while befor I can post the results.

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RJS

It's not a question of money, but wood is precious

From my deflection testing on my last 3 spruce/Indian guitars, the rosewood was roughly twice the weight of spruce at a similar compliance on the unbraced plates. That is simply pathetic. Cocobolo is likely to look even worse in such a test

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Build log

Come on guys.... if he wants to try it and has some extra wood to waste why not try it?

Maybe a cocobolo top with Spruce back and sides?
That would compensate for the heavy top....right?

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Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com

“It's not a question of money, but wood is precious “

"Come on guys.... if he wants to try it and has some extra wood to waste why not try it?"

“Maybe a cocobolo top with Spruce back and sides?
That would compensate for the heavy top....right?”

OK I am convinced. I appreciate your responces to this question. Some things are simply not the smart thing to do. Hope no feathers were ruffled. You folk are to be commended for sharing.

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RJS

Richard,
One thing you might want to think about is a double top. In the link below I talk about how I made a double top out of figured redwood and lutz. The lutz will be on the inside and is only .025" thick. The redwood was about .070" thick.
I have a Washburn D10CE-QSB that I picked up for about $25 on eBay. It is my beach/camping/loaner guitar. The top is laminated and the quilted top layer seems like it is Formica. I know this because when I bought it the bridge had pulled off and I pulled up a little of that top layer. The guitar sounds decent for a sub $400 all laminate guitar.
I think with a little attention to proper voicing and a very thin cocobolo layer, you could get a laminate Cocobolo and lutz top to sound real good. If they can make Formica sound that good with little attention to bracing there's no telling what you could do with cocobolo.
Innovation is a beautiful thing. If you want to make it work, I believe you'll find a way.


viewtopic.php?f=10101&t=22323

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"An adventure is only an inconvenience rightly considered. An inconvenience is an adventure wrongly considered." G. K. Chesterton.

Double-top with hardwood on top - interesting.....

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The member formerly known as erikbojerik....