Cabinetmaker’s glue, also known variously as bone glue, hide glue, pearl glue, Scotch glue and most appropriately, animal glue, is all just collagen, rendered down from left over bits of cattle and retired thoroughbreds. My preferred nomenclature is ‘horse sauce’.
There is a plethora of sites on the internet covering the scientific particulars of animal glue and extolling its virtues, so I won’t venture too far down those paths, however I feel some discourse is warranted here.
It’s not the fact animal glue has held the few discovered pieces of Egyptian furniture together for millennia that I champion the use of the stuff, rather, it’s the convenience (when set up for frequent use), its two-stage setting and its reversibility that I applaud. Plus I’ve grown to relish its sweet smell upon opening the workshop door of a morning.
Horse sauce can do everything modern woodworking adhesives (they’re not glue – glue is sticky!) cannot achieve. Animal glue can be used to rub-joint carcase- and drawer bottom boards together, corner blocks into long case clock cases and drawer stops into chests of drawers. Animal glue sticks on contact, can still be repositioned if desired and won’t creep when dry. There are few, if any, modern wood adhesives as strong as animal glue, yet it’s fully reversible with plain water and a little heat. My use of horse sauce will therefore spare me the hatred and expletives from the mouths of future generations of antique furniture restorers.
Modern wood adhesives have a shelf life. Horse sauce (in its dry form) will keep indefinitely. Even after activation with water, surplus glue can be kept refrigerated or frozen for… well, at least as long as I’ve owned a fridge!
If you’re still not sold on horse sauce, or even tempted to investigate it, then let me entice you further: Horse sauce may be modified (using common household and horticultural substances) to be waterproof, infinitely more elastic (to create coriaceous canvas for making tambour doors etc.) and slower setting (for those jobs that normally turn the air blue, like gluing up a Windsor chair in one go – glue waits for no man). Even the simple addition of a little extra water will slow down the set time. It’s that flexible.
If, for some reason, you don’t employ an unpromising eight-year-old boy to come in to work an hour ahead of you to prepare the day’s glue in a cast iron pot on top of the workshop stove, then there are other, significantly more convenient ways in which to prepare animal glue.
During my career, I’ve had a selection of electric glue pots; some better than others. One brand (the one that seems to be currently available from most woodworker’s shops) lasted about a month – the spun aluminium inner pot developed numerous pinholes.
The glue pot I now use in my woodworking renaissance is nothing more than a perfect little thermostatically controlled wax pot – apparently used for bikini waxing (though why they don’t make the bikinis from waterproof fabric to begin with, I just don’t know).
There’s one final benefit of horse sauce I’ve found invaluable but has gone unmentioned elsewhere. When gluing up, say, a large set of dining chairs, rather than wasting time and effort cleaning up the glue squeeze-out from around all the joints, set the chairs on the floor and let Workshop Dog lick all the joints clean. The savings in expensive dog food can be considerable!