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thedore
02-27-2010, 10:56 PM
I have 4 cells with spiral plates and KOH. It appears that the brass screws I used are contaminating the cell. Time to switch to all stainless. McMaster sells a flux that can be used to solder stainless screws together.

Ted

lhazleton
03-01-2010, 10:11 AM
Ted,
What the hell are 'spiral' plates?????????

thedore
03-01-2010, 11:00 PM
Rather than go with the dry cell design i settled on winding two plates into a sprial design. It is on my website here:

http://www.maverickexperiments.com/

rcflyn
03-02-2010, 06:20 PM
That LOOKS Like it'd be MORE work than a Dry cell... But, to each his own...

To answer your question, YES, KOH WILL Eat Brass... And Copper....
and Yes, that Flux stuff works for soldering Stainless to Stainless.
I Personally haven't used it, but have watched my Stainless supplier Soldier stainless to stainless.. Looks like it works the same as soldering Copper wires to what ever you're soldering them to....

phantasm48
11-18-2010, 06:42 PM
I have 4 cells with spiral plates and KOH. It appears that the brass screws I used are contaminating the cell. Time to switch to all stainless. McMaster sells a flux that can be used to solder stainless screws together.

Ted

So does anyone know where to get stainless pipe fittings then? Or, maybe I could use brass but coat the insides of the fittings with some kind of plastic, so I'd get the rigidity and solder-ability of brass, without it contacting the electrolyte. Or are those nickel plated ones ok?

I ask as I'm thinking of a (new?) design where I would use pour-able epoxy/resin around the edges of the plates and not have a plastic end plate. That means no gaskets to squeeze or degrade, no threaded rod, no torque-ing on bolts. I would align all the plates in an assembly jig type setup by putting removable spacers in between them. Then I'd dip a side of the assembly into a rectangular tray just a bit bigger then the perimeter of all the plates. The assembly will not touch the bottom of the tray so that a solid "wall" would be formed when the tray is filled with pour-able epoxy. Once it's hardened and dried, it will have formed, on one side, a barrier and spacing holding the plates aligned and apart. The dipping process would be repeated another 2 times for the other two sides. Once 3/4 sides are hardened, the assembly jig can be removed from protruding through the 4th side and then that final side will get it's dunking in the resin. Since EPDM seems to be the material of choice, I might even be able to do this with pour-able EPDM, but since it's not rigid, I don't know if it would be a good choice, structurally.

I think aside from relatively unknown effects of electrolyte constantly contacting whatever epoxy/resin I'd choose to use, this design would have NO gaskets or screws and the lead wires could be soldered directly to the middle of each of the end plates as well as the hose fitting.

What are anyone's thoughts on this construction method?

Stevo
11-19-2010, 09:39 AM
So does anyone know where to get stainless pipe fittings then?

McMaster : http://www.mcmaster.com/#5670k85/=9sclj1

or

http://www.dudadiesel.com/fittings.php

For this one, you'll have to step up to a 1/2" NPT and get a 1/2" to 3/8" reducer if using 5/16" clear vinyl line.


For the epoxy, please read my post on the underground here and save yourself some time and hassle:

http://hhounderground.com/Forum/viewtopic.php?f=26&t=171

You're welcome.

lhazleton
11-19-2010, 02:31 PM
I ask as I'm thinking of a (new?) design where I would use pour-able epoxy/resin around the edges of the plates and not have a plastic end plate. That means no gaskets to squeeze or degrade, no threaded rod, no torque-ing on bolts. I would align all the plates in an assembly jig type setup
What are anyone's thoughts on this construction method?

Sounds like a nice idea, but how would you clean your plates should they become contaminated?

sokeway
11-28-2010, 08:01 AM
Brass is not being eaten by KOH, but the electrolysis.

In the system, should avoid using easily electrolytic consumption of materials, such as copper and aluminum.