Temperature Control for Hot Glue

Temperature Control for Hot Glue

Control the Temperature of your hot glue gun with a light dimmer switch from the hardware store.

I have found that there are times when I didn’t want that hot glue as hot as gun can get it. Some hot glue guns get the glue so hot that the foam melts on contact and can burn skin.

The formulation of Readi-Board and EPP foams withstands hot temperatures pretty well, better than the EPS insulation foam (purple or pink foam insulation). My experience is that they melt under the heat of the typical 40 Amp hot glue gun. With this contraption you can dial in the voltage and get your favorite temperature. All you need is a light dimmer and an outlet from your local hardware store.

The inexpensive light dimmer switches that you find at hardware stores are driven with a switching mechanism. Basically, it turns the current on and off for variable amounts of time depending on the position of the knob. The dimmer is turning the power to your light on and off really fast, but the overall current flow decreases as the frequency of power traversing to the filament decreases causing the glowing filament to cool (dim). A hot glue gun is essentially a 40 watt light, a heated filament wrapped around the glue melting chamber. Decreasing the amount of electrons flowing through the heating element will reduce the amount of heat.

Here is a phot of the one I made.

The wiring diagram is very simple. The positive AC line (highlighted red) runs through the dimmer switch before going to the outlet. The ground (black) bypassed the dimmer and goes to the ground side of the outlet.

With this unit set at 65 volts (somewhere around 5 o’clock on the dial), the hot glue flows but doesn’t melt the EPS foam. It is also cool enough to get it on your skin without burning, could be a benefit when working with kids. The downside is that the low temperature settings will not allow the glue gun to deliver high quantities of glue, but this is good for short joints. Glue guns with large heated chambers can still deliver a good quantity of glue.

Here is an example of how it worked. On the left is hot glue delivered from the hot glue gun set at 65 volts. On the right, the same glue gun delivering glue after 120 volts, you can see the bubbles from the air being released from the foam melting. To the far right are the indentations left from the hot glue after peeling it off. Even the cooler glue holds the foam really well, as long as the pieces or joint is created before the glue gets too cool.

I hung the unit on a 2x4 within arm’s length next to my build bench. Note the computer screen so I can watch the build videos at my build bench. Man cave complete!

To hold the hot glue gun I cut a chunk out of a piece of ½ inch foam and mounted it on the dimmer. I also added a night light so I could tell when it was on. The light has saved me quite a few times from walking away and leaving it on.

Another tip is the hot glue holster.

This simple contraption is a 2 inch pipe hanger screwed to the side of my build table. The hot glue drips into the trash can under the holster (not shown). The masking tape on the handle can be removed and replaced when it gets gooped up with hot glue (or other foreign stuff like epoxy). Sometimes my hands, or gloves, get pretty messy while building.

Happy Building!

HilldaFlyer - December 2015