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Beth Music
03-04-2015, 4:13 PM
My husband's mandolin neck has come loose from the body. We have been told that green TiteBond glue can be used to reglue the neck. He tried something similar in the past with it, but the glue only held for about a year. Just wanted to check for any other comments on the best way to reglue without deadening the sound.

george wilson
03-04-2015, 4:23 PM
Once you have already applied glue,and it has come loose,the new glue will just be put on over the old glue,and will be no stronger. Some glues allow joints under strain,like neck joints,to creep. Hide glue does not creep. It would have been best if he had used hide glue for the first repair. Any idea what glue he did use? Old white glues allowed creep.

Jim Creech
03-05-2015, 7:39 AM
I agree with George. It's best to remove all of the old glue before regluing.

roger wiegand
03-05-2015, 8:18 AM
Hot hide glue. Titebond is a bad idea. You need to be able to disassemble neck joints when the neck needs to be reset, hide glue can be steamed apart, titebond not so much. It's easy to re-glue hide glue, as new glue will reactivate the old glue meaning you don't have to take away wood in cleaning up the joint to get a new glueable surface. And, as pointed out, it doesn't creep.

Given the problems you're having it sounds is if the joint was not properly fitted in the first place. You may need to add some wood to the joint (in the form of a glued-in shim) to make a tight joint that will last longer. If it was not put together with hide glue in the first place you need to clean out all of the glue that's in the joint back to bare wood to have hope of making a good joint, this, by itself, will probably loosen the joint enough to require some shimming.

Beth Music
03-05-2015, 9:41 AM
When I asked him last night, he said he just used plain yellow wood glue. He figured he would have to clean all the wood glue off to redo the neck. We have some liquid hide glue. Is that the correct stuff, or do we need to use the powder variety? Once we clean off all the glue, then we need to test fit I'm assuming. How do you know for sure if it's a good fit?

Thanks for all the comments!!!! I truly appreciate the help!

roger wiegand
03-05-2015, 10:48 AM
It's a good fit when it slides together with moderate pressure or light tapping with a mallet and there is no wiggle of any kind and no gaps. Too easy to push together (like it just drops in) it's too loose and won't hold up or work well; too tight (you need to pound on it with your Bigger Hammer) and the joint can be starved for glue and you could break something by forcing it. Liquid hide glue is OK if its fresh. It will give you longer working time than hot glue so will make your life easier at a slight cost in strength.

If this is an old/valuable instrument it may well be worthwhile sending it to a skilled luthier (i.e. not your local music store) for repair-- setting the neck can be a relatively tricky task.

george wilson
03-06-2015, 9:59 AM
The original hide glue is best. Liquid hide glue retains some elasticity even when dry due to the chemicals in it. Original hot hide glue dries crystalline hard,and transfers vibrations better.

Beth Music
03-06-2015, 10:30 AM
Thanks again everyone! I appreciate all the help! Hopefully we can get it cleaned up this weekend and reglued! :)

roger wiegand
03-06-2015, 11:05 AM
It is alleged that Old Brown dries as hard/rigid as hot glue, but that Franklin liquid hide doesn't because of different chemicals used to keep it liquid. Old Brown is just hot glue plus urea, Franklin is more complicated. I've never used either as I find it pretty easy just to keep a glue pot warm when I'm working. I put the glue in a ketchup squeeze dispenser and stand that in a water bath in my glue pot. Easy, always available, and doesn't skin over. I've got a second pot insert for when I need much larger quantities.

Beth Music
03-06-2015, 5:26 PM
Has anyone tried Titebond brand Hide Glue? It's all we have available in town... We can definitely order in some hot glue if needed.

roger wiegand
03-09-2015, 11:33 AM
Titebond is the same as Franklins. It uses ammonium thiocyanate and cyanoguanidine to liquify the glue, vs urea. I'm not aware of actual data documenting any functional difference. Make sure you get a fresh bottle if you go this route, it's a product that can sit on store shelves for a while. Mainly make sure you have a good fit on the dovetail, if it's right almost any glue should work fine.

george wilson
03-13-2015, 7:11 AM
BE CERTAIN that your liquid hide glue WILL DRY before you commit to gluing the neck. It has an expiration date on the bottle,but if stored in a freezing shop,no telling what could happen. Glue up a test piece FIRST to make certain the glue is still good. I have had liquid hide glue that just would not harden. Then,you have a bigger mess on your hands to really get rid of it in the joint.

I NEVER just go by the expiration date.