Questions: Freezing Hide Glue

by Frank Ford

Originally published in American Lutherie #79, 2004 and Big Red Book of American Lutherie Volume Seven, 2015

 

Peter from cyberspace asks:

At one of the discussion groups on-line I read about making a batch of hide glue, freezing it in ice cube trays, then microwaving it to thaw each cube as needed. Doesn’t freezing it change the texture, and therefore how well it will work? Likewise, doesn’t microwaving it change it molecularly? Has anybody done any testing?

Frank Ford of Palo Alto, California responds:

It’s long been standard procedure to mix up hide glue and keep it in the refrigerator for future use, but I don’t know anyone who freezes it routinely. For general interest I recently froze a batch and I saw no difference in its working properties once it was melted in the microwave. But I won’t be likely to freeze glue in the future as it’s more difficult to judge its progress as it melts. Sure, it does mold over with time because it’s food, but it lasts a couple of weeks and I’m happy with that.

I have been microwaving hide glue as my only method of heating it for about fifteen years. It’s a good way to avoid the mess of a glue pot. By heating the glue just before use, there’s no chance to overcook it and reduce the molecular strength as I might if I left it day after day in a glue pot. I just heat 1/2 oz. of glue in a “portion cup” (the kind that hot sauce comes in at the local taco stand) until it melts. Then, I float the cup in a regular coffee cup filled with boiling water to carry over to my bench for use. After I use the glue, I toss the excess. The “experts” I’ve talked to agree that my method is the most conservative and the most unlikely to result in degradation of the glue.

We’re taught to keep the temperature under 150°F, but it’s clear from the literature that the temperature is far less significant if the time under heat is reduced. And I do get great results with my hide glue!