Copper Zinc Tap Water Fuel Cell

[jeanna]

Rebar and galvanized electrical conduit are available, too---especially the rebar in short lengths as scrap laying around building construction sites.

--Lee

Good point, Lee.

I think the galvanized electrical conduit is a great choice.
It is quite cheap, and I bet it is to be found near a new construction.
Maybe in the electrician's truck if you ask nicely. He has to pay the dump to take his trash.

I bought a geodesic dome frame about 5 years ago. It will be a greenhouse soon but has been out in the pacific  NW rain for all these years and there is no even hint of rusting.
I guess they put a really good coat on these because of what they need to withstand in the weather. Keeping the inside wires dry is really important...
Good idea. I like it.

jeanna

[the_big_m_in_ok]

I bought a geodesic dome frame about 5 years ago. It will be a greenhouse soon but has been out in the pacific  NW rain for all these years and there is no even hint of rusting.
I guess they put a really good coat on these because of what they need to withstand in the weather. Keeping the inside wires dry is really important...
Good idea. I like it.
jeanna

@jeanna
There's a local mom-and-pop type of hardware/variety store(good sized, for its niche' industry) in the Castro district(urban neighborhood) here in San Francisco.  They have 3/8" rebar for $.79/ft. 1/2", too.  Copper and steel wire as well.  Common hardware, woodworking tools, etc.

Local supply sources can be utilized if one has the money.  I'm glad I found the place.

--Lee

[b_rads]

Some interesting notes on “Galvanic Corrosion Bimetallic Corrosion” from www.corrosionist.com
   For galvanic corrosion to occur â€" these conditions must exist.
1.   Metals must be far apart on the galvanic corrosion chart â€" this has been posted before, see attached.  The “anodic” metals such as magnesium, zinc, and aluminum â€" are more likely to be attacked by the “cathode” metals such as gold and graphite (in this thread â€" copper).
2.   The metals must be in electrical contact â€" I need to verify this and a simple test should prove if this has the potential to create a current.
3.   The metal junction must be bridged by an electrolyte â€" An electrolyte is simply an electrically conducting fluid, distilled water is an exception.  Low conductivity liquids will be localized to the anode nearest the cathode.  High conductive liquids will attack the anode with a larger area.
The relative area of the anode and cathode has a pronounced effect upon the amount of galvanic corrosion.  A small anode (zinc) and a large cathode (copper) will result in high current density in the zinc, hence a high rate of corrosion.  If the area of the anode is large compared to the cathode, very little galvanic corrosion takes place.  Example â€" It is common practice to use stainless steel fasteners to fix aluminum sheeting or signs, but don’t use aluminum screws to fix stainless steel as the screws may rapidly corrode.

Any ideas how to use this info to build a better â€" cheap â€" galvanic battery?

[the_big_m_in_ok]

Some interesting notes on “Galvanic Corrosion Bimetallic Corrosion” from www.corrosionist.com
   For galvanic corrosion to occur â€" these conditions must exist. ...
2.   The metals must be in electrical contact â€" I need to verify this and a simple test should prove if this has the potential to create a current.
3.   The metal junction must be bridged by an electrolyte â€" An electrolyte is simply an electrically conducting fluid, distilled water is an exception. ...

#2 is correct.  That's why oceangoing ships have these:

http://www.economypoint.org/s/sacrificial-anode.html

#3 is also right.  Sea water is the electrolyte.

--Lee

[jeanna]

@jeanna
There's a local mom-and-pop type of hardware/variety store(good sized, for its niche' industry) in the Castro district(urban neighborhood) here in San Francisco.  They have 3/8" rebar for $.79/ft. 1/2", too.  Copper and steel wire as well.  Common hardware, woodworking tools, etc.

Local supply sources can be utilized if one has the money.  I'm glad I found the place.

--Lee

I am glad you found the place too.

I am just not much of a fan of plain iron to copper galvanic difference. It amounts to about 0.3v so I look for something else.

jeanna