Cocobolo

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TallDad71
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Cocobolo

Post by TallDad71 » Thu Mar 23, 2017 12:11 am

Just built a great steel string with Cocobolo, the back has a pulsating life of its own and I am really pleased.

Now Cocobolo is oily, gluing is tricky as the surfaces have to be oil free to get them to adhere properly. Anyone who has worked with it knows it requires a little more patience, maybe some epoxy and some six inch nails to keeps it in place. :wink:

What would you guys recommend for a finish given its oily nature? I am a big fan of French polishing with shellac, happy to use oil and don't have great skills in the spray department for polys and the like. The wood looks its best when just sanded, before the oils seep to the top, it has a rainbow of hues, pink, purples and greens (almost).

In an ideal world I would sand , fill, sand and then get to work with shellac before the oils got to the surface and darkened it. I fear that this wouldn't be the case and that the oils will still come up and ruin the finish.

I wonder whether the safest bet is just to coat the darkened wood with some spray lacquer!

The benefit of your experience would be very welcomed.
Alan
Peregrine Guitars

johnparchem
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Re: Cocobolo

Post by johnparchem » Thu Mar 23, 2017 2:10 am

Shellac is a great finish for cocobolo. Sand, fill and shellac all sounds good for to me. What do you pore fill with?

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TallDad71
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Re: Cocobolo

Post by TallDad71 » Thu Mar 23, 2017 3:49 am

Those are just the words I need to hear.

I pore fill with a paste made out of a wash coat of shellac and cocobolo dust. The dust is made using an Abranet 240 grit sheet and the end grain from the back and side cut offs. I rub the paste into the pore in a circular motion using my index finger, two or three applications of paste, sanding in between does the job. If I can use my bare finger I must be treating the wood well, as opposed to using industrial grade fillers and thixotropics that stink out my workshop for days on end.
Alan
Peregrine Guitars

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Mark McLean
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Re: Cocobolo

Post by Mark McLean » Thu Mar 23, 2017 6:39 am

Just be careful with all of that cocobolo dust - for skin and respiratory sensitivities. I used to love cocobolo, but I can't work with it any more. It started as itchy rash and eyes. Then I got breathlessness and coughing (hypersensitivity pneumonitis). I know a lot of people have no trouble with it - but affected individuals develop it gradually with increasing exposure. And wash your hands before going to the toilet - there have been cases of nasty penile reactions to cocobolo dust carried on your hands. Some parts of your body can be more sensitive than others!

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kiwigeo
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Re: Cocobolo

Post by kiwigeo » Thu Mar 23, 2017 8:45 pm

You're pore filling method looks quick and easy but is there any sink back on instruments you've finished a few years back?
Martin

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TallDad71
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Re: Cocobolo

Post by TallDad71 » Thu Mar 23, 2017 9:26 pm

Mark McLean wrote:Just be careful with all of that cocobolo dust - for skin and respiratory sensitivities. I used to love cocobolo, but I can't work with it any more. It started as itchy rash and eyes. Then I got breathlessness and coughing (hypersensitivity pneumonitis). I know a lot of people have no trouble with it - but affected individuals develop it gradually with increasing exposure. And wash your hands before going to the toilet - there have been cases of nasty penile reactions to cocobolo dust carried on your hands. Some parts of your body can be more sensitive than others!

STOP you had me at Penile!

When I built my first guitar I had no spare cash to invest on clean air. Consequently my nose got full of walnut, mahogany and spruce dust. This made sleeping very painful as I snored more and my wife antidote is a punch in the ribs! Picking my nose was a daily habit and always three dimensional!

These days my nose is very sensitive, so whenever I make dust I do it at the downdraft sanding table, with the air filter switched to max and a P3 mask on. I like the idea of living long enough to enjoy the sound of my guitars! And now sleeping is almost pain free.
Alan
Peregrine Guitars

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Mark McLean
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Re: Cocobolo

Post by Mark McLean » Thu Mar 23, 2017 9:36 pm

OK. Sounds like you are being careful. As long as you are sanding with a downdraft table, P3 mask and wearing a condom, then you are exercising all appropriate precautions. Enjoy cocobolo at your own risk.

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TallDad71
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Re: Cocobolo

Post by TallDad71 » Fri Mar 24, 2017 12:38 am

"Honey! I'm off to work, but I can't find my keys and my condoms!"

"What!"
Alan
Peregrine Guitars

routout
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Re: Cocobolo

Post by routout » Fri Mar 24, 2017 6:41 am

Makore for me sanded it once gets into the air way and expands no oxygen to the blood .New a guy that thought black wood was safe died of cancer he used it a lot ,Mark is rite be aware air born particulate is certainly dangerous .
John ,of way too many things to do.

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kiwigeo
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Re: Cocobolo

Post by kiwigeo » Fri Mar 24, 2017 10:55 am

kiwigeo wrote:You're pore filling method looks quick and easy but is there any sink back on instruments you've finished a few years back?
Would appreciate a come back on my question when you get a chance TallDad :)
Martin

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