Hot melt glue sticks?

A little Googling leads me to

; the second page gives some recommended 3M part numbers for hot melt for electronics. Digi-Key seems to stock most of those part numbers in small quantities; it's up to you to decide if they are cheap. 3M also has detailed spec sheets on those part numbers, including Shore hardness values.

Standard disclaimers apply: I don't get money or other consideration from any companies mentioned.

Matt Roberds

I started to make my own harder formulation, then found a couple of Kg in a surplus store. I cut up plastic supermarket milk containers, sans labels and caps, until they would break-up further in a motorised grinder. I would then have pushed the flakes into a hot-melt glue gun to extrude out string. Then when cold twist that into "rods".

While on hotmelt. I seem to have broken a glue gun, quite a loud bang. I wanted to change colour of glue stick , so switched on , but did not leave warming-up for long enough before extracting the stick. I must have cracked the ceramic of the wire-wound resistor and a few minutes later , bang.

thanks for the inputs. I really don't need much performance from my glue sticks, just some that harden slightly harder.

Interesting about the milk cartons. I remember once cutting them into narrow strips and using a small butane hot air gun to layer them onto the thing I was fixing. You can do the same thing with the old-school BIC clear plastic pen housings. I should try that again.

Do you mean milk "jugs"? Those 1-gallon square-ish containers for milk and water and such? This is polyethylene, yes?

recycle code sez HDPE

Yeah, high-density polyethylene.

So more plastic welding than gluing...

Nice alternative. Thanks for the idea.

yerp. The professionals use office-grade paper shredders for the macerating part of the process.

I'm sure's talking about actual jugs, a thin "plastic", rather than a waxed cardboard that would seem to be what's used in "milk cartons".

I remember DOn Lancaster talking about 3D printing quite some time ago, except as I was reminded recently, he called it a "Santa Claus Machine".

I'm sure he used a hot glue gun at least for demonstration purposes.

I'm sure there probably are still homemade 3D printers that use them. If so, that's another place to look. They need the "raw material" for the feed, what are they using? The process I've read does sound like what was mentioned earlier about grinding up existing plastic, but I can't remember what they did with the ground up stuff.

I've also read about melting styrofoam and I think plastic coffee stirrers with acetone, though I'm not blank about what the point was. But that might lead somewhere.

Michael

And there's that stuff, I can't remember what, that "glues" by melting the plastic together, rather than gluing. I think it had "methyl" in the name.

Michael

Methyl Ethyl Ketone (a.k.a. MEK) perhaps?

In many cases, toluene or acetone can be used in the same way.

A lot of the glues for acrylic, polystyrene, etc. are just this sort of solvent, in which is dissolved some amount of the base plastic (thickens the glue, improves the ability to fill small gaps which is pretty much nil in a pure-solvent "glue").

Some people make up their own "goopy" glue for acrylic by simply dumping a bunch of plexiglas chips, shards, shavings, and dust into a clean jar, pouring in enough of the appropriate solvent to cover, and letting the acrylic dissolve.

Michael-

Could you be thinking of homemade coil dope?

I'm not sure what the hardness of the resulting material would be, but certainly harder than a styrofoam coffee cup or packing peanuts!

Fred

Yes. Though when I read about it, it was decades ago, and in a magazine.

Michael

Lots of cold-weld 'glue' for plastics (acrylic and polycarbonate, and maybe others) is based on methylene chloride. That is also sold (or used to be) in paint remover and carburetor cleaner. It's best used with ventilation (outdoors), and isn't generally recommended for home use.

I found this recently:

With plexiglass for instance what would be an appropriate solvent? Lenny

Plexiglas is the Rohm and Haas trademark for acrylic (methyl methacrylate) plastic. It cold-welds with methylene chloride, and there are some reports that acetone (methyl hydrate) also works.

Here's a good commercial methylene chloride product...

On Sun, 8 Mar 2015 16:16:30 -0700 (PDT), snipped-for-privacy@gmail.com wrote as underneath :

snip

For perspex etc. Chloroform. C+

I just ordered some yesterday. Weld-on is the major brand in the US. I was told by a plastic working pro that Weld-on #4 is the best for generic use if you're workign with acrylic the first time. Different plastics will require different solvents.

There are modifiers in plastic welding solvents to change drying time, viscosity etc.

The stuff I've used is called Harvasolv, and is guaranteed to give you a horrible headache in 3 minutes of use.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net