by Professor Gene Wengert
Q.
I would welcome any comments you have on animal or hide glues as well as sources of information on it's uses.
A.
Regarding the use of animal and hide glues in wood gluing, I still see them used once in a while, but they are not widely used anymore. A few of the reasons are that they require heat to soften and cooling to cure. This can be a problem, or just a pain in the butt. A PVA joint is often stronger. PVA is more easily spread onto large surfaces. PVA systems, including glue costs, are usually less expensive. PVA glues do not discolor the wood and are more forgiving in some ways. In some sense, it is also the same reason why some people like a Ford rather than a Chevy pick-up truck....
For information about using these old glues, the USDA has an older booklet on gluing. Also, check out some of the used book stores--my favorite is Powell's in Portland, OR--they have a WEB page and a large supply of woodworking materials.
(Editor's note: Powell's Technical Books can be found at: http://www.powells.com/techstore.html)
Professor Gene Wengert is Extension Specialist in Wood Processing at the Department of Forestry, University of Wisconsin-Madison.
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Comment from contributor A:
The gluebond in round tenon joints fails eventually 100 percent of the time. If it was originally glued with hot hide glue, it can be reglued successfully with hot hide glue.
Hide glue is the only glue I know of that will dissolve its own hardened residue... and chairs are the only reason it's still around.
To repair one someone has "fixed" with aliphatics, one is forced to remake the joints by plugging and redrilling.
