Wednesday, March 18, 2009

something old, something glue

I was gathering some stuff for a posting about glue, but then came the injunction against further tool posts, so I let it go... but then it came up today so maybe I can throw this in as yet another tool-related post.

Our Kentucky furniture maker mentioned that he used hide glue - in fact, this is the original glue, used in woodworking for thousands of years and made from the collagen in animal tissues such as hides, hoofs, ligaments, tendons, cartilage, and even bone. Animal carcasses used to go to the "glue factory" (also known as the "knacker") where these leftover remnants were boiled for days to reduce the tissue to gelatin, which is then dried and ground into powder, flakes or granules.

Animal glue in granules

Note: re the cow's head on Elmer's glue, Borden dairies' chemical division is in fact one of the world's largest glue producers. "Elmer" the Borden bull is (or was) "Elsie" the Borden cow's "husband". (strictly for PR purposes)

The word “collagen” is derived from kolla, the Greek word for glue. Collagen is the primary protein in the body. There are many types of collagen throughout the body. Types I & III are the major components of skin, hair, nails, muscles, tendons, ligaments, bones, gums, teeth, eyes, and blood vessels. Type II is the major component of joint cartilage.

Anyway hide glue was the only glue available to furniture makers until around World War I. All the great cabinetmakers from the sixteenth through the nineteenth centuries used hide glue in furniture construction, including Chippendale, Hepplewhite, Duncan Phyfe, the Adams brothers, and Sheraton. To make hide glue, the dried powder or flakes are remixed with water and heated gently in a glue pot. The resulting glue is brown, brittle, hard, and not waterproof.

Today, hide glues are mainly used for making musical instruments like violins, and in antique furniture restoration. They are useful because heat and humidity can be used to release the bond, for example to remove top of a violin without damaging the wood. Water at 140 degrees will quickly dissolve hide glues.

Hide glue can produce a brittle joint - unlike resin glues, a joint will break along the joint, rather than breaking the surrounding material.

If you're ever in the wild and need glue, and don't have time or animal carcasses, you can also make it from pitch, the resinous sap that flows from pine trees.

However you also need to add some organic material. Here's a recipe that uses pitch, charcoal, and moose droppings.

1 comment:

Shannon Wright said...

Wow, that was fast!!!