Gastank Electrolysis
So this is a old trick and the first time I have used it. I remember seeing another site do a write up on how to do this a long while back and I thought I would eventually do it to my ZB tank once i was ready. The problem with my tank is rust was not its only issue. One of the previous owners kreemed it and did a horrible job as by the time I got the bike the kreem sealer was coming apart and it kept clogging the carbs jets. No fuel line filter seemed to really do the job.
So first before I got to the electrolysis I used Acetone to eat up the remaining kreem sealer that was left in the tank. I let the Acetone remain in the tank for about a month, rotating the tank side to side, front to back every other day or so. On the last day i put a 3 foot length of chain in the tank and gave it a good shake before emptying. It worked pretty well as once it was drained all I could see was the rust that was under the sealer. So either the person applied the kreem poorly or its a poor product itself. Ive heard from many others that it was the latter of the two.
To setup the electrolysis to remove the rust from the inside of the tank all you will really need is a battery, couple lengths of wire, water, a sacrificial piece of metal, and some sodium carbonate. For the sodium carbonate you can pick that up at just about any supermarkets household supplies or cleaning section. ARM & HAMMER® Super Washing Soda is 100% sodium carbonate, this is not to be confused with Arm & Hammers baking soda which is 100% sodium bicarbonate. Now from what I have found, not every store carries the super wash variety of A&H. Luckily my friend Jay that did his tank just a few weeks before I got to mine. He did the leg work in reading a bunch of other products at Safeway and found out that Safeways washing soda is also 100% sodium carbonate.
Figure 1 below shows the basic setup. For mixing the water/sodium carbonate mixture I used two scoops (about 4 table spoons) of soda wash to one tank of water. For my anode I ended up using a bent piece of coat hanger and fed it through a rubber stopper so it didn’t make contact with the tank. Picture 1 shows my anode setup after a few hours of current passed through it. This picture was actually taken after about the 4th run. I checked the anode twice a day to clean it and about after the 6th run I had to replace it with a fresh one as it got pretty eaten up. Picture 2 shows this.
Figure 1
The process is relatively simple. As the current passes through the gas tank it moves from negative contact to positive, so what happens is the passing current breaks the rust bond from the tank and cause it to flow to the positive charge on the sacrificial anode. Not all rust actually makes contact to the anode so some may end up floating around in the tank. That is why you should change out your soda wash in the tank ever day or every other day.
You may have to run your electrolysis setup for several days before your finished. It all depends on how bad off your tank is. You will know when your finished when your anode isn’t breaking down much and you see little to no rush attaching to it. At this point you can either give it a good slosh with phosphoric acid and run it clean with gas, or you can coat it with POR-15, which from what ive heard works very good as a tank sealer.
Picture 1
Picture 2
Other tips:
When running your electolysis setup is to hook a trickle charger up to the battery to keep it going. I used my motorcycle battery tender.
If you have somthing other then a gas tank or if you have rust on the exteriour of the tank as well you can alturnitivly suspend the object in a large bucket or drum.
Create a anode with greater surface area by adding bends. 
For your anode use something with a high iron content. Coat hangers actually have a pretty low iron content. My friend Jay mentioned that he ended up using some Ikea furniture keys and they worked better then a coat hanger. Also not all coat hangers are created equl. I used one at one point and when i pulled it out after several hours i saw nothing on it. I doubble checked the contacts and they were fine. So i assume it was made from tin or something with no iron what so ever in it. when i compared it to the other hangers i was using i noticed it had a slight green tinge to it and was a little thinner.
You can follow any responses to this entry through the RSS 2.0 feed. Responses are currently closed, but you can trackback from your own site.