avi66 - 25-11-2011 at 09:14
i have few new MMO anodes:
in the picture its a bolt-nut with Teflon tape coating ... the chlorate cell electrolyte penetrate the Teflon and cause corrosion, i think to
electroplate the galvanized iron of the bolt and nut with some coating, to prevent the corrosion.... someone have suggestions, how to prevent the
electrolyte from climbing to the electrical contacts, or which electroplating coating can be used on the bolt-nut?
Mr. Wizard - 25-11-2011 at 09:42
I would suggest you keep the connection out of the electrolyte. This could be accomplished by forming the electrodes from a longer piece of metal to
start with, or raising the existing electrodes out of the electrolyte.
I don't see how teflon tape, with it's titanium dioxide white colorant would keep out an electrolyte. The way it works in a pipe joint is by
compression. The material is compressed and flows to fill the gaps in the threads as the pipe is tightened.
You might try a silicon caulking, or RTV silicon on the connection. I would remove any MMO coating from the area to alloy a good seal and bond with
the silicon. Cleaning with isopropyl alcohol usually helps the bond.
The Dow chemical company, in it's early years had a lot of luck protecting metal in it's chlorine and bromine electrolysis plants with tar and pitch.
He even bragged in his biography about his crappy low tech wood and tar plant outworked and outlasted his competitors' high tech expensive plants.
Maybe you could dip the connection end into some roofing tar?
How many knew Dow was a real person? ;-)
avi66 - 25-11-2011 at 11:44
cellulose(simple wood) can use as a seal ?
i try prevent use silicone ... because the silicone corrode, and release unknown potential toxic/carc chemical ... so i try prevent material i can get
contact with, which i don't know as safe.
i think electrolysis the bolt and nut in MnSO4 solution to get protective inert MnO2 layer on the surface .... sound logical ?
Mr. Wizard - 25-11-2011 at 13:17
No wood won't seal or protect your connection. Dow used tar covered wood to construct his electrolytic cells. I mentioned the tar as a possible
sealant.
Not knowing how you prepared your MMO electrodes I don't know how putting a layer of MnO2 would protect the copper wire under the liquid. Making
electrodes with long ends to keep them out of the electrolyte may be easier.
m1tanker78 - 25-11-2011 at 14:03
You could try dipping the connection ends in some of the stuff they use to coat tool handles with a rubbery grip. I can't think of the name at the
moment. I imagine the base metal to be titanium so I think you'll still get some seepage no matter what you put on it. Roofing tar sounds good too.
Would using lead connectors help?
Tank
fledarmus - 25-11-2011 at 14:08
The tool dip material is called "Plasti-Dip" here...
Plasti-dip
There is also a material called Liquid Electrical Tape that is specifically for insulating wires that might be helpful...
Liquid Electrical Tape
avi66 - 26-11-2011 at 02:01
the connection will be above water ...like-3-4 cm above, but the moisture chloride gas, and bubbles, will be the threat... i don't think the cover
will behave as anode part ... just for protection.