Hot Glue?

I’m not sure about the weather in your part of the world, but where I am and around much of the United States temperatures are cold. It’s been 13 days since I last saw temps above freezing. When I’m not in the shop, I keep the thermostat set around 40° F. It’s not low enough to freeze water, but it does turn my PVA glue somewhat reptile-like. To get the sticky stuff better flowing, I needed to warm things up, but I didn’t need hot glue.

Your first thought may be to hold the bottle under a faucet of running hot water. Sure that would work, but why waste water? My answer to heating my glue was to toss it into my microwave oven for a time or two.

If you bottle is full, pop the top to allow for expansion. (No, I didn’t learn that the hard way.) My bottle had room inside, so I laid it down and turn on the nukes. After 10 seconds, I flipped the bottle and ran it another 10. Bingo.

It surprised me how warm my glue became, and how easy it was to shake in the bottle. Back in the shop it worked great. Easy to squeeze.

— Glen D. Huey

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One thought on “Hot Glue?

  1. Also be careful — below about 55 degrees F depending upon which glue it is, is known as the chalk temperature. When the surroundings, such as the wood, is below this, the glue will not properly cure. It’s not just enough to warm up the glue above this temperature as a cold room and cold wood will quickly cool the tiny bit of glue.

    Quoting Titebond’s FAQ:
    “Chalk Temperature
    When glue dries, the loss of water pulls the adhesive particles together with
    enough force to form a continuous film. If the drying temperature is below a
    critical point, water evaporation is not sufficient to pull the particles together,
    leaving them in the joint. The dried film in the joint will appear whiter than
    normal. This is known as “chalking” and the critical temperature is the “chalk
    temperature.” When chalking occurs, the glued joint loses strength and could
    result in a failed bond”

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