How to undo hide glue

[Walter Cleeson]

Hi guys.

I need to un-glue an assembly I made with titebond liquid hide glue this past weekend. It's not really a joint. I attached a small emblem of purpleheart about 1/8" thick to a piece of QSWO about 3/4" thick. The emblem is rather small- only 3" by 3/8" or at it's biggest part, but it tapers to about 1/8" in the middle. There is no finish on the wood at this point. I have read that you can release hide glue with heat and steam, but I am not sure how to apply those without damaging the wood itself. Can I use a microwave or should I try an iron over a wet cloth?

I really ought to leave it alone, but it's off by just enough that it's noticeably not centered. Besides, I need yet MORE practice fixing screw-ups. Haven't had a project yet without one. Didn't want to end my streak. :p

Thanks,

-Walter

[Bill Petersen]

Heat alone might do it, but heat and steam would be best. You might try a good heat gun. Hide glue needs to reach about 150 degrees to release. Check out www dot frets dot com. It is a site by Frank Ford a master luthier. Guitars (good ones) are constructed with hide glue and Frank has as excellent site with lots of info on using and repairing hide glue. Lots of info on releasing hide glue joints. Good Luck, Bill

[Doug Shepard]

I know hot water will dissolve it quick. I was using it to work shell glued to a wooden backer then popped it into a bowl of water out of the InstaHot (around 180F IIRC). Took about 1 minute to release,

[Paul Atkins]

If I remember, it seems to me that hide glue holds moisture and that if you brush on alcohol it will make it brittle enough to break the joint easily. This was from some luthiers I met years ago.

[Tony Bilello]

Dont over think this. Just pour hot water into/onto the joint, wait a few seconds and slowly work the joints loose. This is the greatest advantage of hide glue. Also to re-glue, just heat up the joint with a heat gun or even easier - just put a fresh coat of hide glue over the old glue and it will re-melt it.
I used to have a custom woodworking business and refinishing shop. I have done this thousands of times. I am not guessing.

[Walter Cleeson]

Thanks for the suggestions. I had another piece of QSWO that I had tested the hide glue on by gluing a small piece of vernier like bloodwood to it. So I tried to undo that test by soaking the joint. Being as it is a small piece glued to the face of the QSWO, the only way I could see to soak the joint was to dunk the whole thing in a container of hot tap water. I believe that's around 120F or so. I let it soak for 5-10 minutes and I wasn't able to get it loose. I just wound up breaking some of the pieces off. Maybe the water needs to be hotter? I really don't like the thought of dunking my real project into water for that long, but I am green enough to be ignorant about that. it just seems I would risk causing it to cup or bow or something. Should I try again with hotter water?

Thanks again.

[Tony Bilello]

The glue is not water soluable. Also soaking hurts the wood. It also wont melt in 120*. If it did, all old furniture stored in attics would have fallen apart by now.
Make another test piece and just pour some fresh hot coffee on it and it should come right apart. Thats how hot the water needs to be. Hide glue melts from heat. That is the same way it is applied. A glue 'cooker' or glue pot is similar to a hot crock pot. It melts the glue. The glue comes in small pellets or crtstals.

[David DeCristoforo]

A hot putty knife blade should do the trick... You might need to grind a sharp edge on it. Not so hot that it will burn the wood...

[Dave Warner]

I don't have specific experience with Titebond Liquid Hide Glue, but I have taken apart traditional hide glue joints by blasting them with a hair dryer for 10 minutes or so. I've never seen the joint just fall apart, but it will loosen enough that you can carefully pry the pieces apart.

[Walter Cleeson]

I tried a combination of a hair dryer and a putty knife and after about 10 minutes or so, off it came.

I could never get the hot water thing to work on my test piece.

Thanks Dave and David, and all you guys for the ideas.

Tony, I wasn't trying to dissolve the glue by sticking the pieces underwater, I was just trying to prolong the contact with the hot water since the pouring wasn't working for me.

So now my wife wants to know what other appliance I am going to take to the shop. First the iron and now the hair dryer.:D

[Ken Fitzgerald]

So now my wife wants to know what other appliance I am going to take to the shop. First the iron and now the hair dryer.:D


You might consider television, refrigerator, computer, coffee pot.....:rolleyes: