Gasket width?

[BeaverRat]

What is a good width of gasket on the cell? is 1/4th inch a good amount to keep the cell from leaking of is 1/2 inch better? Obviously the bigger the gasket, the less reactive surface area you have...

Thanks

[cabrera]

What is a good width of gasket on the cell? is 1/4th inch a good amount to keep the cell from leaking of is 1/2 inch better? Obviously the bigger the gasket, the less reactive surface area you have...

Thanks

I use 1/16 EDPM rubber with absolutely zero leaks

[lhazleton]

Andy, I think he means the width of the gasket.
It all depends on the type of material you're using. On my 6x9, I'm using 1/16th" EDPM cut about 3/4". On my 6x6, I use 1/8" Buna-N rings & these are only 1/8th" wide and seal perfectly without applying much torque at all. The bolts are barely more than finger tight. The softer the compound, the easier to get a good seal.

[viper_1986_1986]

- 1/4" acrylic
- 8 bolts around the plates to hold it in place with 1" washers
- 4.25" x 5" plate size (4.5"x5" for power platea)
- 13 plates
- PVC liner for gaskets - hand cut to around .25"

Holds together JUST fine. I have an issue with power plates flexing due to the fact that my power plates are BIGGER and are not tabbed.....
As long as its an even pressure on all bolts the 1/4" gasket holds just fine.

In a week or so i plan on trying to cut smaller 1/8" gasket size and see how well that works. Its just a pain to handcut them all with box cutters

[phantasm48]

Hey HHO People,

I'm tossing around construction materials for my first dry cell design. I've been thinking of using good ole $3/tube RTV silicon. I would make a little rectangle holed die to attach to the end of the tube nozzle and extrude the silicon around the perimeter of each plate, laying down a bead with a 3x4mm cross section. I'd make the rectangular hole in the die about 3mm tall by 4mm wide, thus accounting for about a 1mm compression "give" leaving 2mm between plates and hopefully a good seal. I know silicon's an excellent sealer when compressed against a relatively smooth surface, is highly heat resistant, chemical resistant, and non-conductive. Anyone think this wouldn't work?

[H2OPWR]

Hey HHO People,

I'm tossing around construction materials for my first dry cell design. I've been thinking of using good ole $3/tube RTV silicon. I would make a little rectangle holed die to attach to the end of the tube nozzle and extrude the silicon around the perimeter of each plate, laying down a bead with a 3x4mm cross section. I'd make the rectangular hole in the die about 3mm tall by 4mm wide, thus accounting for about a 1mm compression "give" leaving 2mm between plates and hopefully a good seal. I know silicon's an excellent sealer when compressed against a relatively smooth surface, is highly heat resistant, chemical resistant, and non-conductive. Anyone think this wouldn't work?

Silicone will not hold up to KOH and electrolosis. I am sure that you will experiment but you will find that inside of these devices is a very harsh environment. I still have not found any silicone or glue or epoxy type substance that will hold up if exposed to the plate where electrolosis is taking place and most will not hold up anywhere else. Do yourself a huge favor and do not try any type of sealant as a gasket. Many thinks will work for gaskets. I have found Teflon the best but is cost prohibitive. Nitrile is second and only slightly more expensive than neoprene or PVC.

Larry

[IM2L844]

As far as chemical reistance to Sodium Hydroxide and Potassium Hydroxide goes, Silicone is your worst choice.

E.P.D.M. has a better better chemical resistance to Potassium Hydroxide (KOH) than Nitrile and a higher temperature rating. It has the same durometer rating as Nitrile but is a little more pliable and would be your most cost effective option. That's just my humble opinion.

Here is a chemical resistance PDF chart:
http://www.rubbercal.com/files/Chemi...ubber_Cal_.pdf

[H2OPWR]

As far as chemical reistance to Sodium Hydroxide and Potassium Hydroxide goes, Silicone is your worst choice.

E.P.D.M. has a better better chemical resistance to Potassium Hydroxide (KOH) than Nitrile and a higher temperature rating. It has the same durometer rating as Nitrile but is a little more pliable and would be your most cost effective option. That's just my humble opinion.

Here is a chemical resistance PDF chart:
http://www.rubbercal.com/files/Chemi...ubber_Cal_.pdf

With EPDM some of it is colored with carbon black. I did find that at least the stuff I bought conducted electricity just a little. I agree it is the best choice for chemical resistance but care must be taken in making sure it will not conduct any electricity. The stuff I had would also turn the water black. Again caused by the carbon content. At our local rubber outlet I could not find any EPDM that was totally electrically resistant. I know there is some because many folks use it with no problem but I do know that some of it will not work. I am unsure how to tell the difference.

Larry

[IM2L844]

At least we agree that Silicone is a poor choice, but I would like to point something out.

The condutivity of any of these gasket materials is so miniscule that there is no way that 12 to 26 volts of potential is anywhere close to enough to allow a current to overcome their inherent resistance, but even if it were, in order for it to act as a conduit for current leakage the resistance of the gasket material would need to be less than or at least equal to that of the electrolyte between the plates. Otherwise, there is zero chance that any current would follow a path through the gaskets instead of through the electrolyte. It's just not gonna happen.

[BeaverRat]

Just take an ohmeter to it. One with two plates separated by a dry gasket, and another test between two plates of a cell that is full of electrolyte.