I found this on a motorcycle site. I was going to try it on an old boat fuel cell , but did not need to. But it looks promising, and I will try it on another project. has anyone on here tried this ? if so, how were the results ?
I can't read that article on my phone, but I have had excellent luck with the following: First, you are going to need 2 gallons of MetalPrep (phosphoric acid) from your local autobody supply, and an old 110V water heater element. If you don't have an old one, a new one can be had for about $15 from an appliance parts store. Start by emptying the tank and remove it from the car, then get as much of the crap out of it that you can through rinsing, etc. Fuel filler and sending unit holes are the best access points you're going to have. Once you get the tank reasonably clean, seal up everything but the filler, and add your MetalPrep and fill the tank the rest of the way with hot water. Once the tank is full, carefully submerge your water heater element into the filler neck, be sure to leave the wired connections outside of the tank and away from the liquid. Then stand back and drink a couple of beers while watching to see if the temperature of your acid mixture gets too hot. It shouldn't...it should get plenty hot, but just right before the boiling point. If it boils over, you're going to need to top it back off, and then switch the heater element on and off every couple of hours to keep it as hot as you can without letting it boil over. And that's it! Let her sit with the acid mixture in it for about 12 hours or so, and when you're all done your rusty old tank will be new clean grey metal on the inside. Be sure to thoroughly coat the inside of the tank with WD40 or diesel, or a similar preservative when you're done, so it doesn't flash rust. I have had great success with this approach. Also, please be careful! I hope I don't have to spell it out, but when playing with electricity and water, there is a shock risk, so insulate your connections well, and keep them out of the water.
This guy gives the basic electrochemical basis of all reactions. He's got a good feel for it too! http://www.youtube.com/watch?v=l0V4MBKQXjs The reactions taking place in the tank, are reducing the corroded steel when done properly.
Don't know why you need heat? may speed up the process. Phosphoric acid works at normal temps too. Muriatic acid available at hardware stores and building centers works too (Hydrochloric Acid), I mix the muriatic acid (31.5% as bottled) at 45:1 with water, I can derust anything in about 3 days....quicker if you reduce the water. Just works out nice 1 gal muriatic and 45 gal water in a plastic 55 gal barrel.
Thanks for posting this. I was planning to clean and seal a CB350 tank tonight! I'll try this method first before proceeding with the POR15 tank kit I bought for it. Jim
I just pickup a product at napa $30 bucks called RED COAT, it is a gas tank sealer, first rinse the tank, clean the tank with muratic acid then coat the inside of the tank slowly spinning the tank so the red coat will cover the entire inside.Let dry 12 hours and ready to use. Godspeed MrC.
I heard if you dump a bunch of BB's in the tank and shake it around for a while it will help break up the rust....works for old dirtbikes.
I put a 6' length of chain in the tank with a gallon of a 5 to 1 mix of water and Marine Clean. Shake shake shake till it's clean. Rinse and pour in the rust killer mix and shake again. Rinse and leave in the sun to dry inside then seal it.
Remove tank, put some handfuls of lead buckshot in it, drive it around in back of pick-up truck (or big ass car trunk) till clean , or until you forget about it.
Strap it to a cement mixer, after filling it with pea gravel, or wood screws, or ??? http://www.youtube.com/watch?v=ou1559CV1Ac
I took the fuel sender off of my 56 F750 tank up after sitting for 20 years. There was a 1/2 tank of gas when it sat for the 20 years, now the lower 1/2 is black with crud, the top all rust. I washed it with a very strong detergent,ZEP "Steam and clean", with the aid of my 1500 lb pressure washer. I then made a strong mixture of water and ZEP "Steam and clean" and let it sit over night. The next day it was clean as a whistle, no rust at all!.