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I've used TB a million times on oily woods without failure...many of those times without even cleaning with acetone first.  The one time I have experienced failure was using epoxy with purpleheart...for which I have no explanation.  Perhaps over-clamping (definitely wasn't lack of clamping) or the epoxy was improperly mixed?  I really don't know.

 

That said, the science of glues definitely supports using epoxy on oily woods instead of PVAs, so that's usually what I've done ever since I bought the big West Systems kit and I always have it on hand...squirt squirt is all it takes and it's really not that expensive when you consider the amount you get for about $120 and how long it lasts...I've thrown away so much PVA glue because it went bad that an argument could be made that epoxy is actually the more economical option. :)

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I've used a lot of cocobolo in my segmented bowls and have never had a problem w/ acetone and plain old yellow glue. I DO, however, make the joint surfaces considerably rougher than I would for non-oily woods and I hit both surfaces w/ acetone until I'm not getting too much color on the paper towel and for some pieces it would probably have been easier to use epoxy than to do all that rubbing w/ acetone.

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I have used Tightbond "yellow glu" for all of my prjects except for cutting boards and outdoor furniture, for which i use so called  "Ultimate wood glue", also by Tightbond.

I recently bought a small stock of very old Cocobolo and am having trouble getting a bond with the above glues, due, I believe to the density and natural oils in Cocobolo.

Even with a bisqueted joint, a cutting board glued with " ultimate woodglue is seperating and an experimental joint with freshly sanded Cocobolo with a large long grain glued surface

with " yellow glue" popped apart with just one tap, as if there waqs waxwe paper between the pieces.

Apart from screws and other mechanical fasteners, what kind od glues might " get a grip" on this stuff. I am afraid to design a glue only project, even if rabbet's, dado's and splines are involved

until I can find adhesives that will bond to this oily material....... Suggestions??

Any time you deal with an oily wood you need to evict the oil so that the clue can take that space around the fibers. Just as important is to have a good surface. A sanded surface is not a good surface nor is a ripped surface. Any time you crush, burn or burninsh the fibers you will have poor glue joint. With dense woods its easy to do one of the above and you wont be able to see the problem until its to late.

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I think he's talking fine sanding, not sanding in general -- many folks go way overboard -- it's an 'exotic' so will look great with 600g :)

 

1. You want to take some acetone (or similar) to the surface

2. Sand at around 100g to abrade the fibers

3. Resin-based adhesive -- I guess poly may work, but I hate the stuff.

 

The real experts at this are the luthiers -- check-out their forums -- lot's to be learned from those guys/gals....

 

I've seen a few posts on success w/ TB... Water-based adhesive is really not the best choice with oily species... Oil and water don't mix... Some exotics are more oily than others, and don't know where Cocobolo falls on the spectrum, but in general, it's not considered best practice... You may get away with it for years, but the joint may fail (and probably will) at some point... I use West 105/207 for exotics...

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PB, what do you consider a "good" surface, if sanded and ripped don't qualify? Planed or scraped?

Knife cut. Edge gluing dense oily wood needs more care than domestics. Sanding crushes the fibers as does "glue line ripping". I don't advocate glue line ripping most of the time anyways unless your actually equipt, seen to many "custom" cabinet door panels fail. Most small shops don't have the hp to get unburnished rips consistently. I don't know that I would consider a portable planer knife cut just due to the speed of the universal motor. TB is just fine for edge gluing cocobolo provided you do it right and think about the process and evict the oil with acetone.

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Clean knife cut would be better, but how many have the capability to consistently get clean cleaving? Much work with exotics are small acents and would challange those without luthier planes -- and the cost would be prohibitive... And if you process the stock, you still have the length issue... For many, using mid-grit quality sharp friable abrasive is the most viable alternative…

 

I agree about glue-line ripping... Not an option available to most hobbyist shops...

 

 

H2O-based can work if all the oil is gone… It’s not so much an issue for species like Ebony, but still an issue for species like Ipe, Bubinga, LV, etc… Unless you use multiple acetone treatments (or just soak the stock), you aren’t going to make much of a dent… Resin glues are the safety margin --- they’ll still perform if all the oils are not pulled-out... It’s also the strategy most tolerant of user-error… I, for one, sometimes remember to apply acetone olny after the clamps are removed :)  It’s those D’Ohhh moments that resin adhesives address…

 

As for the OP -- Cocobolo is pretty oily and a borderline case... BP's right, if you extract all the oil to the penetration line, then water-based should work... I'll advocate for resin-based if for some reason oil remains after treatment... Or you forget :)

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With edge gluing even a hand plane is better than nothing I cant comment on the difficuly factor. For things like cutting boards that the op is doing a jointer is usually fine. The bit*& I'd guess is keeping the edges parallel but again cant really comment on the difficuly doing it that way either. I tend to size everything that has to be edge glued on the shaper down to about 1" width but really no shorter than 8 or 10 inches. I would assume mose hand tool guys can easily slice off and edge with a sharp plane on pretty small pieces.

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