Rabbit Skin Glue - for Gesso

Hi there everyone,

I recently discovered a painter friend was using dried rabbit skin powder to make glue from.

Does anyone have a brief instructional on how to do this? google pointed towards boiling the skin into a gelatin, but it sounds like the end product is a non-shelf stable jelly. Any idea's how to get it into dried powder? this is a value added product to rabbit raising I never considered before.

Thanks!

TCel

you just dehydrate the hide glue and rehydrate it when you want to use it.

My guess would be that the skin glue is either spray-dried (an industrial technique) or dried in thin sheets (e.g. on aluminum foil or plastic) and then broken and ground up to make a rehydrate-able powder.  Boiled, gelatin-like skin extract is probably what they are selling as powdered skin glue. 

I have used the powdered skin glue to size a canvas, a friend got it in powdered form from an industrial supplier, and when we re-hydrated it it was definitely gelatinous, though it smelled much stronger, kinda like wet rawhide.

If you are not interested in the process of making gelatinous goo into powder, you might be able to paint the goo directly onto canvas or boards, and sell value-added 'all natural, traditional art surfaces' that would be easy to dry and keep. 
I suspect that small, thin chips of the stuff would be as easy to rehydrate as powder; it tends to chunk up, and need constant stirring.

-Erica Wisner

Hi, I'm a vioinmakerin Italy and we use only hide glue. I've recently found this description in a chemistry book (it is for hide glue made from animal bones): let a finely cleaned animal bone soak in 10% hydrochloric acid (HCl) for some days. Then wash it with diluted soda to take off acid residue. Cut this jelly-like piece of bone into pieces and boil with water to solve it up. When it cools down you obtain a thick jelly which you can dry in thin plates to conserve it and on occasion hammer off some chips and soak in cold water. When swollen up heat slowly in water bath, should not boil (!) and use as superstrong glue! Hope this was helpful. Otherwise refer to wikipedia...
Felix

Wow, that's really interesting.

Felix, is the hide/bone glue used for fastening pieces of the violin together or for the finish?

It sounds like your book is suggesting just leaving the thinly spread gelatin out to dry. I guess I'll need to find a surface it doesn't stick to... being glue and all. Very interesting.

Thanks for the input folks.

Hi Tom,
the glue is used for glueing the parts together that makes the completely restoreable (the glue is reversable so that any glue joint can be opened without damaging). But in the late 18th century in Mittenwald/Germany the varnished with hide glue!!! Try to imagine the mess when you want to restore such an instrument. I have worked on two such instruments...
I don't really know how to dry it. I had a quality from France that had the signs of a metal grid on the backside... Maybe first on a glass surface and when it has become thick jelly put it on the grid. The french glue I had was 1/4" thick. You had to put in a cloth and breake it with a hammer into small chips otherwise it takes too long to swell.

Are you going to make it??? keep me posted!! If I find more information I will tell you!
Felix

I am definitely going to make it.

I am in the middle of some distracting stuff right now, but I will be making a few passes at it this winter for sure.

I'll be sure to keep this thread updated with what I learn and my progress.

Tom C

The process of making rabbit skin glue can be seen on this video http://www.youtube.com/watch?v=-8wQvdb3R7E from 33.00 - 40.45 minutes.
It is made from the skins, the pure collogen extracted from the leather.