Electrical Question

[Lead Head]

By density, I meant surface area, sorry about that.

It's definitely stainless though, I did a short test run, I could see rust forming quite eaisly in the water, but I took out the electrodes, wiped them off, and they looked brand new, so it's definitely stainless, but a magnetic grade of stainless.

[Lead Head]

Some help needed, I built a new cell, I have a stainless, and an aluminum. Which plate do I want to hook to postive, and which to negative, so I don't get tons of chrome in the water

[MantaBase]

WHere has ROn been? I apologize in advance for an overly complicated answer.

You want to plate aluminum to the stainless. So, stainless should be on the hydrogen side and aluminum on the oxygen side. So, the anode is the hydrogen side and the cathode is the oxygen side.

Now here, I get confused and Ron should chime in. I learned electricity in a chemistry sense and that means I tend to reverse things (ROn can tell you why). The anode attracts negative ions because its positively charged (lacks electrons) - but I think that means you hook it to the negative side of the DC. The cathode gets hooked to the positive side.

Wanna know why I get confused - lol - Ask Ron. It's a common confusion for people with my background. In my world electrons flow from negative to positive. In DC, I think its opposite.

[MantaBase]

Originally Posted by Lead Head

Some help needed, I built a new cell, I have a stainless, and an aluminum. Which plate do I want to hook to postive, and which to negative, so I don't get tons of chrome in the water

BTW - you have been very safe this whole time - and you thought this simple experiment out very well (except the gas collection?). Kepp the cell ventilated and watch the water - if it turns red I but you are backwards - but Ron knows more.

Manta

[Lead Head]

Well at first, my first version, I just collected the gas in balloons, then set the balloon on fire (from a distance) just to get an explosion. But I plan on running an engine and some other experiments, there is no way my cell will be able to hold any kind of real pressure (milk jug cut in half, and glued together with hot melt glue), I plan on just having a hose with a valve on it to control flow.

[Reloadron]

Sorry, I have been keeping up with the thread, but pretty busy. Manta was doing great.

If you use aluminum and stainless for the electrodes your positive (anode) electrode will generate the Oxygen and the negative electrode your hydrogen.

Also, your path for your current flow will ne negative to positive through the electrolyte solution.

I did advocate the use of a little salt in the water to enhance the process as it will make the electrolyte more conductive. Manta is absolutely correct in that you will get the biproduct of a little chlorine gas from the salt. The chlorine molecules would bond with the oxygen molecules. That would be the positive electrode. I figured as long as you don't take to inhaling the gas, the amount would be minimal and not harmful.

Likewise the use of stainless will leach a few biproducts. Therefore logically I would likely make the stainless the positive electrode since the hydrogen is what you are collection and the positive electrode will be vented off anyway.

Let's see, it's 5:30 AM and I need to get to work which includes a bank and gas stop this morning. I will add more later. Hopefully a quiet work day awaits.


Ron

[Reloadron]

OK, having survived a trip to work with gas and bank tossed in here I am again.

First a note on the use of stainless steel:

Why you should not use stainless steel electrodes for electrolysis

Many people using the electrolysis method for rust reduction swear by stainless steel, stating (incorrectly) that it's not consumed, stays clean and seems safe.

Stainless steel is indeed consumed when used in the electrolysis process, although slowly. The main problem with using it is the hazardous waste it produces. Stainless steel contains chromium. The electrodes, and thus the chromium is consumed, and you end up with poisonous chromates in your electrolyte. Dumping these on the ground or down the drain is illegal. The compounds can cause severe skin problems and ultimately, cancer. Hexavalent chromate is poisonous. These compounds are not excused from hazardous waste regulations where household wastes are.
These compounds are bad enough that government regulations mandate "elimination of hexavalent chromate by 2007 for corrosion protection."

Does your electrolyte turn yellow? That's a sign of chromates.

If you have been using stainless steel for the anodes (positive electrodes), wear rubber gloves when working with or near the liquids. If you need to dispose of it, allow it to evaporate into powders and dispose of the powders in sealed containers during your local "hazardous waste clean-up days".

Best bet - don't use stainless steel no matter how tempting it is.

Personally, for a smalll household experiment I don't see a big issue as it is not like you are becoming a hazardous waste dump. However, that is what is said about the use of stainless steel regarding chromates.

During any electrolysis process the electrodes will break down and there will be some biproducts either in the form of solids or gas.

The surface area of your electrodes figure strongly into things as well as the spacing. Less beating the physics to death, water in a pure form is a lousy conductor of electrical current. The actual resistance of water is generally measured in Mhos (ohms spelled backwards) and the mho is a unit of conduction. Resistance and conduction are reciprocals.

The idea here is good conduction. You want your water (electrolyte) to be conductive. The better the conduction the less voltage needed to get current flow and make things happen.

Adding a small amount of sulfuric acid will enhance conduction also. I am sure a Google will yield other possible additives, each having good and bad points.

Ron

[Lead Head]

So I want my stainless to be on the hydrogen side , and the aluminum to be on the oxygen side, to have as little possible chromium in water as possible? I did a little test run with just straight water, I just hooked it up any which way, and I was getting lots of bubless of the stainless, and the aluminum had bubbles that were clinging to it, and not letting go. But water was not discoloring at all.

[Lead Head]

Just did an initial test run, had hooked backwards at first. Noticed that the water started to turn yellow quite fast. Luckily, when I bent down a bit to change the connections around, I noticed abit of water on my hands, and a slow leak in the bottle. Looks like I will be looking for something other then hot glue to hold it together. I have some epoxy, but I don't know if I have enough to cover the whole seam.

Anyways, after I hooked it back around, the water color actually seemed to clear up a bit, but I was pushing some serious current. My transformer output dropped from 9.7vDC to around 7.4DC. It threw my multimeter into the "Out of range" mode , even though it was set to its highest 20amp vDC amperage metering setting, and my fuse was getting quite hot. I think it may be a slow blow fuse, which is no good in my case. Looks like I have to tweak my salt-water ratio a bit then what I usually have to , since my cell is now more efficient.

Anyways, about electrolysis, is it just total current that matters when doing it, or wattage? Like will a higher voltage allow it to happen faster, or is that just current? I ask because back when my 250 watt 10kv transformer still worked, I tried some electrolysis with it, just for fun, and really nothing was happening.

[Reloadron]

OK, in a bit of a nutshell. Lets lookie at Watts. Watts is the unit of measure we apply to Power much as Volts is the unit we apply to EMF (Electro Motive Force), Amps is the unit for current and Ohms is the unit for resistance. They all inter relate. There are several formulas, but at a glance, Power is equal to Volts X Current, Current is equal to Resistance (in Ohms) divided into Voltage (in Volts), Voltage is equal to Current times Resistance. Those are all basic variations of Ohms Law.

Now looking at a tank. The water offers resistance to the flow of current. Now if you just shove two meter probes into some water and measure the resistance you will note as the distance between the probes is increased, so goes the resistance. The surface area of the probes figures in but overall as the probes are moved apart the resistance increases.

Now if we look at Ohms Law we can see that in a circuit Resistance and Voltage are inversely proportional. Resistance increases and current decreases. Remember the current flow through the water is what produces our gas. More current = More gas.

The discoloration you saw was the chromic acid in the water. That is the bad stuff we talked about. You don't want that effect.

Important for now is understanding the current flow through your electrolyte.

Ron