Page 1 of 1

Super Glue joint repair

PostPosted: Thu Feb 01, 2018 10:19 pm
by Bob Howell
I glued two 3/32" maple and rosewood strips to sides of fretboard as bindings, with super glue. The joint did not close up in two places and I must make some repair. I can plane it off or repair joint.

I watched Eric melt super glue with a hair drier in his roseate video. Amazing. Later read after drying all that is left is some plastic like plexiglass or something.

Can I melt it with heat and clamp again successfully? I used it for simplicity. Now I have a mess.

I have a little iron to shrink model airplane wing covering which will work great. Will it work here?

Re: Super Glue joint repair

PostPosted: Thu Feb 01, 2018 10:22 pm
by Barry Daniels
That would be a new one for me. I have never seen CA glue melt under heat. Why did you not use Titebond for this wood to wood joint?

Re: Super Glue joint repair

PostPosted: Fri Feb 02, 2018 12:59 am
by Mark Swanson
i wonder that also. If you truly do have a mess as you say then it would be better to do it over. Use wood glue.

Re: Super Glue joint repair

PostPosted: Fri Feb 02, 2018 3:19 am
by David King
You don't have to plane it off if you can use a CA debonder, especially if it's just a short section that needs to come apart. The debonder from Bob Smith is like smelly water and it has to sit for a while to melt the glue. Perhaps debonder is what Eric was getting heated up with the hair dryer? That's something I've done and it does speed it up a little if you keep reapplying the debonder as it evaporates. However I don't think it will rebond later, the debonder kills the CA unlike acetone which will reactivate it to some extent.

Re: Super Glue joint repair

PostPosted: Fri Feb 02, 2018 10:12 am
by Chris Reed
Heat does soften dried CA, which is only acrylic plastic after all. You can heat and clamp to see if that will close the gap up enough, though of course your softened acrylic in the joint is pretty stiff so it might not squeeze out sufficiently.

Heat and a thin blade would remove the binding but leave a plastic residue, so planing off would probably be best if you have to replace the binding.

I can't see any downside to trying to close the gap, so long as you don't scorch the wood.

Re: Super Glue joint repair

PostPosted: Fri Feb 02, 2018 10:28 am
by Christ Kacoyannakis
Tom Bills in his Luthier's Edge class dealing with fretting shows glueing the binding to the fretboard with CA glue. I have done it, and gotten great results, but you have to basically have the two pieces flush and tight together when you do it. You just lightly clamp them or tape them and spot glue in 4 or 5 places, then go back and wick in thin CA glue to really glue the whole thing together. I don't know if I'll do it again, because I think I would rather use hide glue (I am getting away from plastic of any kind and switching to all wood bindings). Hide glue will draw the two pieces together for a really tight looking glue joint.

Re: Super Glue joint repair

PostPosted: Fri Feb 02, 2018 11:30 am
by Alan Carruth
Acetone will dissolve CA.

My understading is that reaction with alkaline sites on the substrate is what initiates curing of CA. The first coat uses up all of those, which is why subsequent coats can fail to cure, annd you could run into that trying to re-glue the thing after getting the old stuff out. A little baking soda applied to the outside of the joint can get things going. I often rub baking soda into the surface of acid woods like walnut to speed things up, dusting off the excess.

Re: Super Glue joint repair

PostPosted: Fri Feb 02, 2018 3:15 pm
by Bob Howell
My problem was using thick sg. I thought it would be stronger than thin wicked into the joint; no so. I will wick it into clamped joint in future. Tape seems best here.

Re: Super Glue joint repair

PostPosted: Fri Feb 02, 2018 8:41 pm
by Barry Daniels
Thick CA does not wick as far as thin. You want maximum, if not total penetration.

Re: Super Glue joint repair

PostPosted: Sun Feb 04, 2018 4:42 am
by Bob Howell
My hobby heating iron did the trick. Closed up the joint and wicked thin sg in after the wood cooled. I have used yellow glue to attack fb to neck but now think epoxy would give strength to insure durability here. I'm seeing builders mention it to keep water out of neck assembly.