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Gluing Cocobollo
Posted: Sun Jan 22, 2012 12:43 pm
by Dave long
My nexted guitar will have oilly cocobollo, maybe I'll glue the braces on wt. epoxy... The back on the rim wt. titebond and the braces on the top wt. hide glue, hows that for talken glue....If we know everything about glue then no one has to post about this again :)
Re: Glue strength
Posted: Sun Jan 22, 2012 12:59 pm
by ken cierp
I have a sensitivity to Cocobollo so we don't have it in the shop -- I read an article by Norm Abrams the "New Yankee Carpenter" guy and his strategy for gluing is to clean the surfaces with acetone apply the glue immediately, position and clamp. He indicated the the cleaning gets the oil out of the surface pores only a short time -- and they will eventually leach back to the surface if not filled with glue.
Re: Glue strength
Posted: Sun Jan 22, 2012 1:09 pm
by Dave long
Ken, I heard that too. What would you use to glue the kerffing on to the cocobollo and then back braces..One of the Kens on the other forum had fits with it, if you rememember. his braces came off and such. I don't want to use epoxy but .. well..
Re: Gluing Cocobollo
Posted: Sun Jan 22, 2012 3:24 pm
by Bob Matthews
I suffered from an almost catastrophic failure with gluing cocobolo on one of my early guitars. The back braces were glued onto a cocobolo back that I had vigorously cleaned the surface with acetone because of something I had read, I used hhg.
The following day when shaping the braces I noticed one of the brace ends coming loose from the back, so I tried to peel it up some more and to my horror, within ten minutes had managed to remove all the braces and centre re-enforcement strip with hardly any damage to the back or the braces. The glue residue that remained on the bracing was a very similar colour to the cocobolo.
I posted this problem on several different luthier forums at the time and the general consensus was that using a solvent on oily wood actually brought more oil to the surface than it removed - my failure seemed to have proved this. So I scraped the whole of the back to create a fresh surface and within 15 minutes re-glued using hhg. The guitar is still perfect 4 years down the line but it was a lesson very well learned and I will never again use any solvent on oily wood prior to glue up.
I did find one recent discussion on the subject, see here
http://www.mimf.com/cgi-bin/WebX?128@24 ... @.2cb6ba69 but have also read many more and it seems the myth was started by something written on the 'Franklin' web site!
Re: Gluing Cocobollo
Posted: Sun Jan 22, 2012 3:46 pm
by Dave Bagwill
Good information and great documentation. Thank you.
I'm sure we will hear more on this subject.
Re: Gluing Cocobolo
Posted: Sun Jan 22, 2012 5:02 pm
by Ray Ussery
Lots of folks using Cocobolo, so it's obvious there are successful ways of gluing it. I find it incredible that things like this seem to be such closely guarded secrets.
I appreciate you sharing your experience. Like Ken,I too am allergic to the stuff, so while it's a beautiful tone wood it won't be an issue with me. :)
But this is a direct quote from LMII and it may explain the use of acetone.
" Use either our FGSMI All-Wood Epoxy or the FG wood glue. Wipe the gluing surface with acetone and glue up as soon as the acetone has evaporated (usually a minute or two)."
http://www.lmii.com/CartTwo/thirdproduc ... Wood+Epoxy
The term "FG wood glue" is evidently a reference to their polyvinyl white glue that a lot of folks use. My only personal concern is it will spoil and it has a horrible smell when it does and it seems to have marginal quality control..one time it's pretty good and the next...well you get the idea. Anyway, again.. just my personal opinion. :)
Ray :)
Re: Gluing Cocobollo
Posted: Mon Jan 23, 2012 11:01 am
by Dave long
Thanks guys for all that input, I was reading the site Litmus posted, and holy cow those guys are going at it. Good stuff because in the archery world I was taught to use acetone to clean wood when glueing. So it not just in the guitar world. Anybody else please pipe in, because I LOVE cocobolo so please keep this going.