Changing the KOH
KOH is available at most local science shops, or from the science shops on the web. You may also contact us and we will sell you enough KOH for the change. An alternative is to use NaOH (sodium hydroxide), available at any grocery or hardware store as Red Devil Lye or in many drain cleaning products. Make sure to use a product that contains only NaOH. NaOH is not as efficient as KOH, so a slight drop in power and efficiency may result.
1. The KOH does not need to be changed for a very long time as long as distilled water is used and the system is kept in proper balance. This can be months or years before a change of electrolyser KOH is needed.
2. To change the KOH remove the two outlet tubes and reconnect the "jumper" tube between the O2 and H2 sides.
3. Cut the 4 zip ties holding the unit in place.
4. Remove the electrolyser and take it to a sink. (This is a great way to get rid of that clog in the drain!)
5. Turn the faucet on, remove the "jumper", and turn the unit upside down until the KOH is drained.
6. Use the syringe and add some distilled water to flush the unit, then dump down the drain.
7. Replace the electrolyser back in the mounting base and secure it with zip ties, replace the O2 side hose.
8. Mix a solution of 1 part KOH to 3 parts distilled water by weight. (An eyeball measurement is good enough, the amount does not need to be exact.)
9. Mix the KOH into the water slowly, in a container that will withstand heat, and it is best to put the mixing container in a flat bottom tray with water. The mixing of KOH and water generates considerable heat. Do not make more than a few ounces, as not much is needed to fill the electrolyser.
10. When the KOH is completely dissolved use the syringe to draw an ounce at a time of the KOH solution.
11. Hook the syringe to the H2 side and slowly fill the H2 chamber. MAKE SURE THAT THE O2 SIDE HOSE IS CONNECTED. Before disconnecting the syringe pull the syringe back to near its starting position to put a slight vacuum on it.
12. When the H2 chamber is filled 1/2 in. from top, reconnect the H2 hose. Disconnect the O2 hose and fill the O2 chamber. MAKE SURE THE H2 HOSE IS CONNECTED BEFORE FILLING THE O2 CHAMBER.
13. While filling the O2 chamber make sure to keep an eye on the H2 chamber so that no KOH is forced out. To keep the KOH from being forced out add small amounts and pull the syringe back to avoid creating too much pressure.
14. Connect the O2 hose and set up the unit for operation.
15. Thoroughly wash any items that came in contact with the KOH.
Some of the How's and Why's
The vinegar is needed to neutralize the KOH. Otherwise the KOH will slowly move through the system and eventually damage or destroy the fuel cell.