?Reflowing? hot melt glue - telescopic brush for mains water.

Hotmelt glue does bond quite well to clean aluminium etc but the temperature of the metal has to be quite a bit higher than the hotmelt melting temperature for a good bond. Use a hot air gun to heat the metal, trying at different distances with an old radio antenna or selfie-stick to practise on, when cold pulling at the glue to check the bond

Hot glue dissolves in propanol. Remove the old and apply new

Hotmelt also takes time for the heat to soak into the glue. Hot air gun, and warm it, taking your time. Maybe prehat in boiling water, which should get everything warm but not yet melt either glue or plastic

Or: strip off the glue, meths often causes the bond to break. Gets under the glue, and it peels off.

and then glue:

Two-part adhesive as in epoxy?

On car dent pullers where you attach a plastic piece to the car panel with hot melt glue, and then use a slide hammer attached to the plastic piece, spraying Isopropyl Alcohol 99.9% is the method of removing the hot melt glue from the panel. The IPA just needs to get between the glue and panel to break the bond. However this method only breaks the bond and the short exposure to IPA leaves 99.99% of the blob of glue intact. In the OPs case the bond is already broken and it's the bulk of glue stopping the pieces from becoming apart.

A quick Google suggests that hot melt glue is usually applied at 160C but will probably start going soft at 100C. The aluminium pole will act as a very good heatsink so just pouring boiling water over it may not work. Sticking the end in a saucepan with water at a rolling boil for a few minutes may soften the glue so a bit of physical force may get the the pole and the plastic screw bit apart.

Hot melt is soft at 60°C

In a break from the s***ty DIY job I've been putting off for weeks/months

I took a stick of generic hot melt glue and placed it in a pan of hot water, with the water being heated to various increasing temperatures.

75C as the 65C case but the colour of the stick was becoming transparent

100C (simmering boil). Pulled apart with ease with slight force BUT not hot enough to stick to anything.

In the above the glue stick was left at temperature for around 2 minutes and around 4 minutes to see if I could get the end 5 cm hot enough to stick.

Thanks to all for the useful suggestions so far.

However I should point out that the issue isn't getting the bits apart. The bond has already broken. I need to reflow the glue to remake the bond or apply a new glue.

Cheers

Dave R

That is consistent with my experience of the hobby grade hotsnot too. You can definitely handle it before it is capable of holding stuff together

Then use IPA to remove what's left of the old

ue.

As a follow-up to my previous test heating hot glue to 100C I put a 1 inch length of the hot glue stick in a tub of IPA at 13:00. Now at 23:00 the stick doesn't seem to have changed at all.

No, it absorbs it very slowly. What happens is that IPA seems to break the bond. Not change the glue chemistry.

If you soak hotsnot in IPA it doesn't dissolve but it seems to cease to stick and can be peeled off

But that's exactly how it seems to work

Useful information.

NB: there are "low-temp" hot melt glues, ISTR max temp of 60 °C or so -- used so anklebiters don't cook and peel their skin when hot-melting things together.

Top Tip: hot melt can be used to clean tools, i.e. a blob of glue squeezed between the ridged jaws of pliers peels off, taking dirt in the ridges with it. Useful for removing metal filings sticking to magnetic things taaw.

Thomas prufer

Neat.

Ive found it fairly handy for low strength bonding of PLA 3D printed parts.

The model plane boys use it to bond foam plastic

Also as a sort of zip tie to locate and control cable movement, and to tack in repair sections of plasterboard prior to skimming/painting.

It's another tool in the DIYers toolkit of adhesives and chemicals.

Yes, as I posted before I had a car dent puller where a plastic pad is hot glued to the car panel and a slide hammer is attached to the pad to pull the dent out*. A quick spray of IPA will break the bond between the plastic pad, car panel and the hot glue. Looking on Google it seems that various other "liquids" will do th same with hot glue with respect to breaking the bond enabling the blob of glue to be removed. In the OPs case the blob's bond to the pole is already broken but still inaccessible to be removed as it will be beneath the plastic screw cover. IPA may not be the answer to the OPs problem if attempting to re-glue what is already in the fitting. The IPA will do the reverse of what the OP wants as it will make the glue non-sticky rather than reactivating the bond.

The panel beaters at Ford's (and presumably other car manufacturers) were among the most highly paid of the specialists.