Fingerboard Ivoroid Binding Trouble? Long Post...

[bpatrick]

I'm working on two ebony fingerboards for mandolins 6 & 7. I first installed the binding using thin Duro CA glue wicking into the gap between the FB and the celluloid ivoroid. Prior to installing, I also wiped all gluing surfaces, binding and board with denatured alcohol. Also used a slight touch of baking soda/water. Everything went on well and I set them aside to dry for around 24 hours. I then began cleaning them up starting with sanding the bottom flat. Then I moved to the fret side to radius to 12" and noticed that the binding on the nut end of one FB was loose. I spot glued it back down. I then noticed another was loose in the same area. This time, I slightly tugged on the binding to see if the glue job was acceptable. It came off with slight resistance.

I pulled all the binding off, cleaned everything up and reapplied with Gorilla brand CA. I also cleaned all surfaces with alcohol. No baking soda this time. Again all looked well, but I decided to test by pulling a bit. Again the binding came off with only slight resistance.

This led to an experiment. On scrap pieces of ebony fingerboard, I tried Duco, Duco with a touch of acetone, epoxy, gorilla brand CA-gel & thin, Duro CA, Kwik-Fix CA, Loctite Professional CA, epoxy, Titebond PVA, and melted acetone ivoroid glop. I also varied the test with a bit of moisture, some baking soda, acetone, alcohol on some CA samples along with straight use. There was no real winner. I would call the grip "mediocre" or "bad" for all of them. The glop may have offered the slightest bit of more resistance. I also tried the Loctite CA on a piece of pine with the same results. I would have used some Satellite City Super T, but it was dried up and not locally available. I also considered HHG, but did not try.

Maybe I'm just expecting too much of a bond between ivoroid and ebony using CA and other glues? Has anyone else tugged on some fingerboard binding? I'm about to order some more Special T as I've had success in the past. Maybe it will prove to be better than all the other clues in my experiment? Any thoughts?

[Bluetickhound]

The only thing I've ever used to bind fretboards and headstock overlays is the thin CA that Highland Hardware sells. No baking soda or anything else and bindings are very firmly attached.

[bpatrick]

I forgot to add Weld-on #16 to the list...no bueno either...although it might have been a bit old.

[bernabe]

I pulled all the binding off, cleaned everything up and reapplied

How did you "clean it up"? did you sand back to wood again? If not, that could be your problem imo. Leave out the baking soda/water. CA or Duco should work with binding to bare wood.

[bpatrick]

Yes, totally cleaned up the binding and wood. Sanded the wood bare and scraped and sanded the binding clean. Also experimented by using the unglued side of the binding along with fresh binding pieces. After getting everything clean, the samples were wiped with denatured alcohol.

[sliebers]

I use medium thickness CA from StewMac with no problems. I tack it up with medium a few inches at a time until I get everything wrapped around and then go back with some water thin both top and bottom edges. I also use thin pieces of teflon in the fret slots to keep the glue from flooding into the slots.

If something isn't lined up right, I can peel it off and scrape the glue off the wood. It does take a bit of force to peel it back. I've never had it fall off on it's own yet. I also do not use anything to neutralize the acid in the ebony.

[sunburst]

Ivoroid binding, even very well glued binding, will pull right off, in my experience, no matter what it's glued with. It will, however pull chips of spruce if you just grab it and pull it off from around a top. Binding is not structural, so the relatively poor bond is generally not a problem.
I've glued ivoriod bindings with Duco cement for nearly 30 years with no unexpected failures (though I had to start adding acetone when the formula changed). I've used CA a couple of times when I didn't have time to wait for the bindings to shrink after the solvent "swell" caused by Duco, and I have had equal success with that. I don't do anything to prep the wood or the binding surface for gluing, other than freshen the wood surface soon before gluing by lightly scraping or sanding.

[Nevin]

If there is a problem, I wonder if it is with the binding rather than the wood. Is it possible there was some residue from the cutting process that is on the binding?

[bpatrick]

Thanks John for the comments. That makes me feel better about the situation. I guess I just expected a better grip from the glue. The binding isn't falling off by any means, it was just surprising to me that it did not take more force to remove. I've never tried to remove the ivoroid from a guitar or mandolin's fretboard once I applied it and so far, none of those instruments have shown any signs of the binding coming off. In the past, I've used both duco and CA.

Once removed, the ivoroid shows some blackish glue areas, so it appears that a small amount of ebony fiber is coming off with the binding. This indicates to me that some measure of good adhesion is taking place. Maybe not a death grip, but adhered somewhat firmly. I just received some Bob Smith Insta Cure CA. I'm going to go with that and see how it goes.

Pretty sure no residue from the binding or wood is in play. I had wiped the surfaces clean with a bit of denatured alcohol.

[ProfChris]

No experience with ivoroid bonding to ebony, but it is known that oily woods can be a problem if you wipe them with solvents because you are releasing and spreading the oils on the surface. It might be worth an experiment glueing to a recently sanded/scraped surface which has not been wiped with anything (other than perhaps a clean, dry cloth).

[bpatrick]

I tried with no alcohol wiping, just wiping with a dry clean paper towel to remove the dust. About the same result. I don't think that ebony (African) is terribly oily. Nothing like Indian rosewood or cocobolo.

[Bernie Daniel]

As I read though all the different glues you tried (impressive collection!) a thought ran through my skull -- is it actually ebony and ivoroid (celluloid) or did you get some other kind of binding by mistake? A vendor could have sent the wrong thing by mistake I guess? Is the binding holding on the spruce top and maple back? If so some problem with the ebony surface?

[bpatrick]

The binding is authentic celluloid ivoroid binding from Axiom Inc and African ebony from LMI.

I re-glued the binding last night using Bob Smith Industries super thin Insta-Cure CA. I used the capillary technique holding and clamping the binding against the fingerboard while adding the glue to the seam. The glue grabbed quickly and seems to have set up firmly. Prior to gluing the fingerboards, I tried the glue using the capillary method on a couple of samples and let them sit for 6 hours or so. The binding was harder to remove. A residual wide adhesive area with ebony fibers covered the width of the binding. This indicates to me that the super thin CA is penetrating well and making the best bond possible.

I believe I have a winner. I'll "stick" with the Bob Smith Industries or Satellite City CAs in the future.

[John Arnold]

I have been using Bob Smith Industries CA for a long time. I recommend it without hesitation.
Loose fingerboard binding is a very common problem on vintage guitars. For the most part, I repair them by wicking in thin CA.
One of the advantages of celluloid binding on vintage guitars is that it can usually be removed cleanly in one piece and reinstalled if desired. This is not the case with most other plastics.