rust removable by electrolysis

seabat · Post by **seabat** » Sun Nov 15, 2015 12:34 pm

Hi all
New member of about 4 months, I had a very rusty fuel tank on my '66 CL77 and was reading up on the process here on the forum.
The one thing that I was unable to find is how long do you have to keep the tank in the solution to get all the rust out and if I leave it too long will it be damaged by the electrolysis solution?
All help will be very appreciated by me.
Thank you all seabat

Seadog · Post by **Seadog** » Sun Nov 15, 2015 5:50 pm

In general, how long an object remains in the solution depends on how badly it's rusted. Leaving it shouldn't hurt it, assuming you're just using washing soda and water. I've left things in the tank all day. I also like to use hot water when mixing it up. I'm also assuming that you're not submerging the tank , but putting the solution and electrode inside the tank only. Electrolysis is line of sight. Submerging the whole tank would remove rust on the outside, but not the inside.

seabat · Post by **seabat** » Sun Nov 15, 2015 6:17 pm

thank you seadog for the quick reply. also for the advise on the process. sorry to say, I placed the whole tank in the solution. Now I will have to figure out how to plug the holes in the bottom of the tank because I removed the petcock
any other advise would be greatly appreciated.

Seadog · Post by **Seadog** » Sun Nov 15, 2015 7:10 pm

Uh oh. You'll probably have to paint that tank exterior. Ive done a great deal of electrolytic rust removal, but not on a painted surface that I wanted to keep. I just de-rusted a CB engine cover and left the paint on the reverse side. The process removed it all.

You need to get a negative electrode inside the tank with the electrolyte. It cannot touch the inside of the tank. You might try to use a bent coat hanger. You might also try to put a piece of foam on the end to keep it from touching. Use a cork to plug the petcock hole. Use a short piece of hose with a wooden pencil stuck in it for the tank crossover connection. Make a plug out of wood or something similar for the gas inlet with a hole in the middle for the electrode.

Also consider a chemical de-rusting agent as an alternative to electrolysis. I just recommended a product called Evaporust to someone else on the forum. This is what I used recently on two gas tanks with spectacular results. They were not terribly rusted though.

Good luck and let me know if you have more questions and how it works out for you.

EDITED TO ADD THIS LINK:
http://www.honda305.com/forums/viewtopi ... erust+tank

seabat wrote:thank you seadog for the quick reply. also for the advise on the process. sorry to say, I placed the whole tank in the solution. Now I will have to figure out how to plug the holes in the bottom of the tank because I removed the petcock
any other advise would be greatly appreciated.

seabat · Post by **seabat** » Mon Nov 16, 2015 9:21 am

Again thank you Seadog, before I take the tank out of the solution I am going to try sticking the negative poles into the tank while it is still in the solution.
will let you know how that works out.

seabat

Seadog · Post by **Seadog** » Mon Nov 16, 2015 9:37 am

If you mean that you're going to reverse the polarity, ok, I don't know what it will achieve, but ok. If you mean that you're going to simply drop the negative into the electrolyte, NO! You'll short circuit your power supply!

seabat wrote:Again thank you Seadog, before I take the tank out of the solution I am going to try sticking the negative poles into the tank while it is still in the solution.
will let you know how that works out.

seabat

seabat · Post by **seabat** » Mon Nov 16, 2015 5:29 pm

here is what I did, I am using re-rod and taped a flat piece of wood to the bottom and rapped the rod with electrical tape where it rests against the tank opening. Hookup the negative lead to the tank and the positive lead to the re-rod. It seems to be working well as there is a lot of bubbles coming up through the filler hole.
again thank you Seadog for all your help and advise on this problem. I'll wait a couple of days till the bubbles stop, then pull the tank and inspect the inside with a mirror and flash light.