Adhesion issues with cocobolo

[Jacob Porter]

Ok, working on my fourth build and I'm using cocobolo for the fretboard. After carefully thicknessing, tapering, sanding, and then wiping the cocobolo with alcohol (multiple times with the alcohol), I glued it down with titebond. 24 hrs later, unclamping and the cocobolo can be separated from the neck with my fingers. So, two questions:

1. What's the best way to remove the fretboard without damaging it?

2. Is there a better glue for coco? Gorilla glue?


Thank you,

Jacob

[Steve Rolig]

Can't say I've had a lot of experience with cocobolo but on a recent guitar I used cocobolo for fret board, binding and bridge. I always glue the fret board with epoxy - no problems on this guitar and I use LMII instrument glue for bindings and bridge and also no problems with adhesion. I wipe with naptha rather than alcohol, I don't know if that would make a difference.

[Mark Swanson]

This is a myth that is very persistent, and comes up here quite a bit.
You do NOT need to wipe cocobolo with anything. The wiping here is what has created your problem, folks think that it's helping "get rid' of oils that stop adhesion, but it doesn't.
All you need to do is just give a fresh surface to the glue. Freshly scraped or planed is the best. All I do is scrape it with a sharp scraper just before gluing and I never have a problem, with wood glue or epoxy.

[Chuck Tweedy]

I second Mark's response.
I have used cocobolo extensively for both fingerboards and bridges. It will glue as well as any wood if you freshly scrape the surface before applying hide glue or Titebond.

It is a very resinous wood, and those extractives are soluble in ethanol. SO - if you wash it with ethanol, you will coat the entire surface with that resin. Not much is going to stick to that.
Suffice it to say, I've proved time and time again that if you glue a fresh surface it will stick as well as any wood.

[Randy Roberts]

I have to join Mark and Chuck, although Mark is too polite in calling this a myth.
Stop and think it through. If whatever you are going to "wipe off" the resins with is going to do anything, it must be able to dissolve the resins. When you put the solvent, alcohol or whatever, on the wood surface it is instantly going to be sucked down in the wood, where it will dissolve the resins down in the wood also. As the solvent evaporates at the surface the adsorbed solvents that are down deep are drawn to the surface, along with their absorbed resins. the solvent evaporates, leaving the resins from deeper in the wood behind on the surface.

Just like arguing with your wife, you will never win this battle. You may think you have, but besides smearing the surface resins all over the surface as Chuck said, you now have brought even more resins from deeper down up to the surface.

For the glue to stick to the wood it needs fresh chemical wood "sockets" to bind the glue's "plugs" into. By scraping the wood surface just before gluing, you provide millions of fresh empty "sockets" for the glue. If the surface sits for any length of time, the wood surface oxidizes and all your sockets are now already plugged with Oxygen molecules. Picture your wood surface as the same as a surface of steel. The wood surface essentially rusts and the glue cant bond, just like paint won't bond to rusted metal. This oxidizing of the wood surface takes place fairly rapidly. Someone here (I think Al Carruth?), felt your wood surface is probably fairly degraded in as little as 15 minutes. I usually scrape the surface, no matter what the wood, just before I grab the bottle of glue, no matter what the glue (although epoxies are a little different game in how they work).

So there's our three sense <g>

[John Kingma]

I've used cocobolo quite a bit over the past several years and have not had a problem. I don't wipe them down (for the reasons already given) with anything. Just scrape them and glue them. I use epoxy exclusively for fretboards.

[Jacob Porter]

Thank y'all for the help. I got the board off with a hot butter knife and have now sanded the neck and board flat and clean of glue. Went ahead and applied new glue and clamped while still fresh. Now the waiting while I work. Thank you all again for the expert advice.

Jacob

[Chuck Tweedy]

So to get the fingerboard off, if the following statement is true:

24 hrs later, unclamping and the cocobolo can be separated from the neck with my fingers.

Then it should come off very easy if you work it off with a putty knife.

EDIT: Oh sorry - didn't see that last post. You did the right thing.

[David King]

I wouldn't trust cocobolo to glue well with urethane glue. I've had good luck with CA believe it or not. You do have to move fast because the cocobolo is basic and causes the CA to cure very rapidly. Stick with titebond but make sure your caul put significant forward bow into a neck /fingerboard joint. I can't emphasize enough the need for fresh glueing surfaces. Don't wait overnight, don't wait 20 minutes, joint it and then glue it.

[Mario Proulx]

Umm, glad I didn't find your "advice" when I was getting started...

I've been using polyurethane glue for jointing all rosewood backs, including cocobolo, which is the wood I use the most, since the late 90's... Not one single glue failure! None. Zip. Nadda.

Poly glue. Trust it.

[David King]

Mario, what brand are you using? I've done tests with probond between fresh coco and maple and not been pleased.

[Chuck Tweedy]

I'm interested to. Seems the only poly glue I can find now is Gorilla. I think they pushed everyone else out of the market.
Just like an ... 800 pound - yes you guessed it - gorilla!!
I crack myself up. sorry

[Mario Proulx]

Elmer's Probond(AKA Elmer's "Ultimate"), or Excel One.

http://www.excelglue.com/excel-one.html

Only reasons I can think of for a bad joint with poly glue are old glue(buy small bottles, use it all up as soon as possible), not enough moisture, not enough clamp pressure, too short clamping time, or poor joinery.

I'm especially wary of old glues, and always seek the newest, freshest I can find. I then set myself up to glue-up as many items as I can with it, which for me are all rosewood/cocobolo back joins, and all my CF bracing laminations. I also use poly glue to glue my truss rods(aluminum one way U channel or solid, non-adjustable) into the neck, but this being a less critical joint, and having a lot of surface area, I'm not as fussy for fresh glue as I am for the rest.

[David King]

Freshness is an issue with most glues. Franklin makes it tougher yet with their silly date codes. It's difficult to source any glue that isn't already a year old so even though I buy fresh every year I'm not always very confident in what I have.
When I first started with polyurethane glue I had to bring it back from Denmark. Eventually I could buy it in France and then finally in the US starting maybe 15 years ago.

[Mario Proulx]

All you have to do is either do a Google search to decipher the various manufacturer's codes, or call them up. From there, it's a simple task to find the freshest batch. I often find bottles that are 3 or more years old on the shelf; pity the poor fools who know no better.... But for damned sure, don't blame the glue itself....

[David King]

I have yet to run into a bottle on the store shelves that's less than 8 months old even if the store claims it just came in. One more reason to have a cell phone when you go shopping.

[David King]

I contacted Excel via their website and asked a few questions. They promise to always ship fresh glue. They claim the viability of unopened glue is 9-12 months before using it up. Best stored refrigerated until opened.
They have offered to send samples.

[Tom Sommerville]

I read a tip on a website recommending a test to determine if a wood can be glued: wet the surface with water and observe what happens. If the water beads up on the surface, glue will not adhere reliably.

It's for water-based glues, obviously.