Subject of this test is graphite mixed with various glues, as a electrically non-conductive thermal glue/potting mix or maybe as e. conductive ‘wire glue’*.
The graphite used was Heinz Kleickmann Graphit naturrein (naturally pure) Schmiermittel für Zylinderschlösser […] (lubricant for barrel-locks, etc etc.).
The glues were mixed in a ~1:1 ratio by volume (bit more for epoxy, clumsy accident), which in most cases was close to the point of complete saturation; then 8 mm were smeared on cardboard. 1 cm pieces of wire were inserted 4-5 mm apart. The wire was straightened and cleaned with rubbing alcohol beforehand, tweezers were used for insertion. Glues were allowed to cure for 6 hours.
Glues tested:
151 Epoxy Adhesive, quick setting 4-6 minutes
Hard surface. High strength. Bond strength can be increased, curing can be delayed somewhat by using proportionally more gel from the right chamber (resin, left is hardener). Known carcinogen while un-cured, harmless afterwards. Use gloves.
Not conductive.
Ponal Express wood glue
Retains some flexibility after curing. Fast curing (5 minutes), water-soluble.
250kΩ
Pattex Hobby allround crafting glue
Your avg. translucent water-soluble alround glue.
No clear reading on wire. 10-20MΩ (still fluctuating) measured poking into the glue at the base of the wires.
Pattex Classic Kraftkleber (power glue)*²
Thick, honey-like gel containing rosin. Couldn’t find english info on this stuff.
3.3kΩ - lowest reading
Super Glue (cyanoacrylate)
Lowest viscosity of all, great for filling hairline gaps. Gloves/eye protection recommended. Curing time can be lowered by breathing at it (reacts with humidity).
No conductivity.
Epoxy and Super glue were also tested by direct poking at ~ 1 mm distance between electrodes. While the epoxy remained non-conductive, for super glue readings between 2.5k and 25kΩ showed. Maybe something in the glue oxidized the wires, preventing electrical contact.
*You might want to try this recipe http://www.instructables.com/id/Make-Conductive-Glue-and-Glue-a-Circuit/?ALLSTEPS if you’re looking for a more effective wire glue.
*² Kraftkleber Classic
Feel free to add your own readings.
Edit: pics
setup
wires
glue blobs
mirrors:
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