Information provided from The Traditional Bowyer's Bible, Bois d'arc press:
- Hide Glue
- Hide glue has approximately 10,000-plus lb. of tensile strength. Hide scrapings, a by-product of buckskin tanning work well. Hide scraps should be pulverized, since the paper thin hide scrapings release their glue faster than sinew. Quick-cooked first-pouring hide-scrapings glue takes only one hour. Otherwise, let the mixture simmer at 170 degrees for ten hours, or until the scrapings are no longer diminishing in bulk.
You can make permanent liquid hide glue by adding acetic acid, or vinegar. Flexible hide glue can be made by adding glycerin in weight equal up to the dry weight of the glue. (Used for book-binding in times of old.) To make it water resistant just add tannic acid, formalin, or formaldehyde. These can be added either to the surface to be glued, to the glue surface, or can be mixed with the glue. Tannic acid can be extracted from tree bark, especially oak. Old literature reports that hide glue can be waterproofed by adding 40% linseed oil, but tung oil works slightly better, however the results are only mildly water resistant. (Formaldehyde occur naturally in woodsmoke so if the glued surface is held above a smoking woodfire the treatment is applied at the same time as it is dried by the heat.)
To make hide glue water resistant just add tannic acid, formalin, or formaldehyde. (Formaldehyde's occurs naturally in woodsmoke so if the glued surface is held above a smoking woodfire the treatment is applied at the same time as it is dried by the heat.) I believe this method for making glue water resistant applies to plant resin as well.
Offered by Jan.
Here's another source for Hide Glue.
Offered by Lou.