Posted on January 19, 2010September 10, 2025 by Dale Phillips Questions: Freezing Hide Glue 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!
Posted on January 19, 2010September 10, 2025 by Dale Phillips Questions: Toxicity of Odorless Superglue Questions: Toxicity of Odorless Superglue by Bill Hunter Originally published in American Lutherie #82, 2005 and Big Red Book of American Lutherie Volume Seven, 2015 Ralph from Austin, Texas asks: I recently read on a luthier e-mail list about a guy using odorless cyanoacrylate glue for filler. The brand he uses is by Satellite City, maker of Hot Stuff™ and UFO™, which stands for “user-friendly odorless.” I know from experience that vapors from CA glue are not friendly to the eyes or to the respiratory system. My question is: if it has no scent and you don’t have any skin exposure, does this mean it’s rendered totally nontoxic or nonirritating? The bigger question is: how are products made odorless? Are there just blocking agents so that we are unable to detect them, but they’re still there, and therefore still irritating or toxic? Bill Hunter of Simi Valley, California, cofounder of Satellite City, answers: “Toxic,” in general implies a lasting or long-term harmful effect. Cyanoacrylate adhesives are not toxic except to those who are allergic to them. The same could be said of milk, peanuts, and grains. “Irritating” is comparable to the feeling one gets in the eyes and nose when dicing onions. The scent is not what irritates the eyes, nose, and throat, it’s the fumes. And, of course, if the fumes are masked, a product can give the unrealistic impression that there will be no irritation. In fact, the scent of many chemicals is a good gauge by which to judge exposure. If, on the other hand, there is no scent because there are no fumes, you have the best possible working conditions. Hot Stuff “UFO” instant adhesives have been relied on by folks who have allergic reactions to typical cyanoacrylates since 1988. Many of these people can’t be in the same room where an instant glue is being used without a violent reaction. No problem with “UFO.” It’s the only CA they can use. Regarding skin exposure: Skin exposure, even for typical cyanoacrylates, is not a consideration for 99.99% of users, and in thirty-five years, I have never, ever heard of anyone being bothered in any way by skin exposure to “UFO.” Note: Mr. Hunter also sent me the MSDS on CA glues, which didn’t help me understand. I tried to follow-up Mr. Hunter’s answer and he repeated the above information. I’d like to hear from some of you with sensitivities to the regular stuff and perhaps others who understand the chemical lingo. A product so seemingly integral and essential to modern lutherie certainly deserves a little scrutiny.
