connecting wires to pencils underwater

[Adam Funk]

I'm interested in the prospect of using pencils as electrodes for
electrolysis of water, but I'm trying to figure out a way to attach
the wires from the power supply to the other end of each pencil so
that the electrical connection is sound but I can seal it up to
immerse (so that the exposed electrodes are underwater in tubes).


Here's a pencil example, but the gases from both working ends are open
to the surface.

https://upload.wikimedia.org/wikipe...9/Electrolysis.svg/220px-Electrolysis.svg.png


I'd like to make something structurally more like these examples, in
order to capture the gases separately, but AFAICT I'd need either
U-shaped pencils (!) or a way to attach the wires to the pencils
securely under (I guess) heat-shrink insulation.

http://www.sciencephoto.com/image/4185/530wm/A5000248-Electrolysis_of_water-SPL.jpg

http://www.miniscience.com/images/WaterElectrolisis.gif


Suggestions?

 

[[email protected]]

I'm interested in the prospect of using pencils as electrodes for
electrolysis of water, but I'm trying to figure out a way to attach
the wires from the power supply to the other end of each pencil so
that the electrical connection is sound but I can seal it up to
immerse (so that the exposed electrodes are underwater in tubes).


Here's a pencil example, but the gases from both working ends are open
to the surface.

https://upload.wikimedia.org/wikipe...9/Electrolysis.svg/220px-Electrolysis.svg.png


I'd like to make something structurally more like these examples, in
order to capture the gases separately, but AFAICT I'd need either
U-shaped pencils (!) or a way to attach the wires to the pencils
securely under (I guess) heat-shrink insulation.

http://www.sciencephoto.com/image/4185/530wm/A5000248-Electrolysis_of_water-SPL.jpg

http://www.miniscience.com/images/WaterElectrolisis.gif


Suggestions?

Alligator clips (test clips) covered with Sugru (check sparkfun.com ).
The teeth of the clips will make good contact with the pencil "lead"
and the Sugru (a moldable silicone that dries hard in 24 hours) will
provide water proofing.

 

[Jasen Betts]

I'm interested in the prospect of using pencils as electrodes for
electrolysis of water, but I'm trying to figure out a way to attach
the wires from the power supply to the other end of each pencil so
that the electrical connection is sound but I can seal it up to
immerse (so that the exposed electrodes are underwater in tubes).

Here's a pencil example, but the gases from both working ends are open
to the surface.

https://upload.wikimedia.org/wikipe...9/Electrolysis.svg/220px-Electrolysis.svg.png

That's an "artist's impression"

I'd like to make something structurally more like these examples, in
order to capture the gases separately, but AFAICT I'd need either
U-shaped pencils (!) or a way to attach the wires to the pencils
securely under (I guess) heat-shrink insulation.

http://www.sciencephoto.com/image/4185/530wm/A5000248-Electrolysis_of_water-SPL.jpg
http://www.miniscience.com/images/WaterElectrolisis.gif

Copper electrodes will work too but will taint the water, with carbon
electrodes some carbon decomposes at the anode but the CO2 formed has
the same volume as the O2 it replaces so the text books ignore it when
discussing stochiometry.

If the goal is to produce more than samples of the gasses, for
improved results use stainless steel electrodes for electrolysis
in a dilute caustic soda solution.

 

[ehsjr]

I'm interested in the prospect of using pencils as electrodes for
electrolysis of water, but I'm trying to figure out a way to attach
the wires from the power supply to the other end of each pencil so
that the electrical connection is sound but I can seal it up to
immerse (so that the exposed electrodes are underwater in tubes).


Here's a pencil example, but the gases from both working ends are open
to the surface.

https://upload.wikimedia.org/wikipe...9/Electrolysis.svg/220px-Electrolysis.svg.png


I'd like to make something structurally more like these examples, in
order to capture the gases separately, but AFAICT I'd need either
U-shaped pencils (!) or a way to attach the wires to the pencils
securely under (I guess) heat-shrink insulation.

http://www.sciencephoto.com/image/4185/530wm/A5000248-Electrolysis_of_water-SPL.jpg

http://www.miniscience.com/images/WaterElectrolisis.gif


Suggestions?

Run insulated wire all the way up in the test tube, then down to
the pencil above the liquid level. Here:

test tube
+------------+
| +--+ |
| | | |
| | P |
| | E |
| W N |
|**I**C *****| <-liquid level
| R I |
| E L |
| | v |
| | |
|__|_________|
|
|
+---WIRE-------------------

I didn't draw the beaker - the above is placed into
the beaker with the wire leaving the beaker at the top.

Ed

 

[Jasen Betts]

Run insulated wire all the way up in the test tube, then down to
the pencil above the liquid level. Here:

test tube
+------------+
| +--+ |
| | | |
| | P |
| | E |
| W N |
|**I**C *****| <-liquid level
| R I |
| E L |
| | v |
| | |
|__|_________|
|
|
+---WIRE-------------------

I didn't draw the beaker - the above is placed into
the beaker with the wire leaving the beaker at the top.

Ed

Not shown in the pictures linked in the original post is that the
setup starts with the test tubes full of water.

 

[Adam Funk]

Not a bad idea.

Not shown in the pictures linked in the original post is that the
setup starts with the test tubes full of water.

I'm probably going to use plastic tubing leading to some kind of
vessels rather than test tubes.

 

[Adam Funk]

That's an "artist's impression"




Copper electrodes will work too but will taint the water, with carbon
electrodes some carbon decomposes at the anode but the CO2 formed has
the same volume as the O2 it replaces so the text books ignore it when
discussing stochiometry.

If the goal is to produce more than samples of the gasses, for
improved results use stainless steel electrodes for electrolysis
in a dilute caustic soda solution.

Good point. I could probably connect the wires to some bits of
stainless with small bolts & nuts, then shrink-wrap over them.

 

[ehsjr]

Not shown in the pictures linked in the original post is that the
setup starts with the test tubes full of water.

Does that make a difference?

Ed

 

[Jasen Betts]

Does that make a difference?

only if the goal of the looping the wire round to the top like that was
to keep it dry

 

[Adam Funk]

Alligator clips (test clips) covered with Sugru (check sparkfun.com ).
The teeth of the clips will make good contact with the pencil "lead"
and the Sugru (a moldable silicone that dries hard in 24 hours) will
provide water proofing.

That looks like fun stuff, thanks.

 

[Adam Funk]

Copper electrodes will work too but will taint the water, with carbon
electrodes some carbon decomposes at the anode but the CO2 formed has
the same volume as the O2 it replaces so the text books ignore it when
discussing stochiometry.

If the goal is to produce more than samples of the gasses, for
improved results use stainless steel electrodes for electrolysis
in a dilute caustic soda solution.

What would happen with zinc-plated steel (bolts, for example)?

 

[Jasen Betts]

What would happen with zinc-plated steel (bolts, for example)?

probably be pretty messy, unplated steel would be better.

 

[Les Cargill]

What would happen with zinc-plated steel (bolts, for example)?

The zinc will probably get involved. Remember the copper/lemon
juice/zinc battery from grade school science?

 

[Adam Funk]

probably be pretty messy, unplated steel would be better.

Well, I was tinkering around with a scrap bit of stainless steel rod
(unthreaded) & trying to figure out how to attach a wire to it so I
could shrink-wrap the connection; then came up with the idea of a
stainless steel bolt & an eye crimp; then realized I only have (AFAIK)
zinc-plated & brass bolts, no stainless ones.

 

[Adam Funk]

The zinc will probably get involved. Remember the copper/lemon
juice/zinc battery from grade school science?

I figured that would probably be the case, but it doesn't hurt to ask
(usually).

 

[Jasen Betts]

Well, I was tinkering around with a scrap bit of stainless steel rod
(unthreaded) & trying to figure out how to attach a wire to it so I
could shrink-wrap the connection; then came up with the idea of a
stainless steel bolt & an eye crimp; then realized I only have (AFAIK)
zinc-plated & brass bolts, no stainless ones.

silver solder if you're equipped, borrow a spot welder for 20 seconds,
plate the end with copper and solder to that,
even a bullet type connector as used in auto electrics.

 

[Adam Funk]

silver solder if you're equipped, borrow a spot welder for 20 seconds,
plate the end with copper and solder to that,
even a bullet type connector as used in auto electrics.

Checking my Rolodex to see if I know anyone with a spot welder...

Thanks again for the tips.