Hot melt glue - how to unglue something

[Robert Marshall]

I am considering using hot melt glue to mount completed bowls, platters, hollow forms, etc., to a stand-alone slow-turn (2 rpm) rotisserie for epoxy finishing. I might use a small face plate glued to the underside of the bowl, using hot melt glue. So it's probably going to be a temporary metal-to-wood hot melt glue joint.

(I am NOT doing this epoxy finishing on my lathe, for several reasons, mainly cleanliness. Epoxy works better in a "clean-room" environment, or as close to that as you can get, which is not my turning shed. So I'm building this rotisserie for the sole purpose of slow-turning epoxy-coated wood-turnings, while the epoxy cures.)

My question is simply this: how do you "un-do" that hot melt glue joint? Is it just a matter of heating the metal face plate until the glue releases? If so, what would you suggest for the heating, that wouldn't burn the wood at the glue joint?

(I have the feeling this question has been discussed here before, but I can't figure out how to get the Sawmill Creek search engine to search for the entire phrase, "hot melt glue", without returning results which match either "hot" or "melt" or "glue" or any combination thereof, which is way too much. Would love to know how, if it can be done.)

Thanks!

Robert

[Edward Dyas]

I think that would work but you would need to heat the faceplate first. Hot glue doesn't stick to steel very good because the surface cools it too fast. Then when you are done gently warm the faceplate with a hair dryer or heat gun and it should come off.

[Grant Wilkinson]

I put blue painters' tape on both the faceplate and the bowl, then use hot melt to glue the pieces together. When I'm finished with my finish, I just peel the tape off both pieces. No muss, no fuss.

[David Bassett]

... but I can't figure out how to get the Sawmill Creek search engine to search for the entire phrase, "hot melt glue", without returning results which match either "hot" or "melt" or "glue" or any combination thereof, which is way too much. Would love to know how, if it can be done. ...

Try adding "site:sawmillcreek.org" (without the quotes) into Google, or your preferred search engine, and they should honor the quotes and search for your phrase while limiting results to this site. (Or whichever site you specify.)

[Don Frank]

If you put the item in the freezer for a while the glue becomes really brittle and it will pop off easily.

[John Beaver]

Good suggestions from Grant and Don. Don't try to heat it as the heat can crack the wood. Isopropyl Alcohol can help unstick it.
Hot glue is best used to tack the corner of a joint, rather then flat surface to flat surface. This way you can just cut it at the joint.

[Mark Daily]

If the blue tape doesn’t work for your situation, you might coat the area of the bowl where the glue is going to go, with shellac or something similar to insure it doesn’t penetrate or “grab” the wood.

To remove the glue you can spray it with some freeze spray used in electronics to instantly freeze it. Then it will come off easily.
Reheating the glue will just make a mess.

[Robert Marshall]

Thanks, everyone, for a lot of useful information.

Here's my "epoxy-tisserie". It consists of a rotisserie motor sold on Amazon for craft purposes, which comes with a PVC shaft that fits over the square shaft of the motor. The motor is toward the rear of this photo. To that I have added a length of 1.25" (ID) PVC pipe, which fits over the provided PVC shaft and locks onto it with a cotter pin that goes through the PVC pipe and shaft. I boxed it all up using a wine crate and plywood scraps. The bowl/platter end of this slow-speed rig (2 rpm) is a PVC bushing adapter into which is screwed a PVC plug. The plug's flat face acts as the face plate (to be hot-glued to a bowl or platter, when in use.) Since the thing is turning so slowly, there's no need for bearings; the shaft is held in place by holes through plywood panels, holes which are slightly larger than the diameter of the shaft.

So my mounting plan is to tack the PVC plug to the center of the bottom of the bowl or platter which is to be epoxy-coated, with hot melt glue around the perimeter of the plug. Then screw it onto the epoxy-tisserie. When done with the epoxy application and cure, I will freeze the hot melt glue, so as to pop the PVC face-plate off the finished bowl or platter.

Screenshot 2019-11-08 at 9.08.58 PM.jpg

Can't wait to try it out. If it works, I'll post an update. If not, you never heard of me.

Robert

[Tom Giacomo]

This is a view of my finishing jig. It consists of a rotisserie motor a 1/2" bolt threaded into a piece of 1" x8 threaded rod to go into my vises and faceplates.
When using a faceplate I use a wood block and glue my project to it with hot glue. I spray heavy coats of lacquer with it. To release the hot glue I use alcohol around the hot glue joint in a few minutes it will release the hot glue. Also it dries quickly so not to raise the grain or wet the wood.

[Mark Daily]

Thanks, everyone, for a lot of useful information.

Here's my "epoxy-tisserie". It consists of a rotisserie motor sold on Amazon for craft purposes, which comes with a PVC shaft that fits over the square shaft of the motor. The motor is toward the rear of this photo. To that I have added a length of 1.25" (ID) PVC pipe, which fits over the provided PVC shaft and locks onto it with a cotter pin that goes through the PVC pipe and shaft. I boxed it all up using a wine crate and plywood scraps. The bowl/platter end of this slow-speed rig (2 rpm) is a PVC bushing adapter into which is screwed a PVC plug. The plug's flat face acts as the face plate (to be hot-glued to a bowl or platter, when in use.) Since the thing is turning so slowly, there's no need for bearings; the shaft is held in place by holes through plywood panels, holes which are slightly larger than the diameter of the shaft.

So my mounting plan is to tack the PVC plug to the center of the bottom of the bowl or platter which is to be epoxy-coated, with hot melt glue around the perimeter of the plug. Then screw it onto the epoxy-tisserie. When done with the epoxy application and cure, I will freeze the hot melt glue, so as to pop the PVC face-plate off the finished bowl or platter.

Screenshot 2019-11-08 at 9.08.58 PM.jpg

Can't wait to try it out. If it works, I'll post an update. If not, you never heard of me.

Robert

Very ingenious- should work fine!