Gas tank rescue

[Guest]

So the time has come to revive my fiance's original '81 750L. Pulled the carbs a LONG time ago and finally got around to rebuilding them. They were bad. 4 days each in the Berrymans with some new o-rings from Robert and all was good to go. Bike fired right up. Now on to the gas tank. It sat for 6 years with a fair amount of fuel in it which reduced itself to a dry varnish mess. And I mean it is in big chunks in the lower areas of the tank. I am planning to liner the tank but need to get it clean first. Paint is shot as well as the petcock so anything goes. I have read lacquer thinner and a handful of nuts and bolts as well as ammonia etc the list goes on. Anyone here have a preferred method in a situation like this? Thanks in advance.

[Nessism]

If you are going to line the tank you might want to purchase the Por-15 kit. It comes with a product designed to remove varnish such as you mention.

[ShadowFocus603]

It may take a bit to do the liner so that's why I am looking for opinions to get the tank clean at least to start with. Thanks for the heads up on that kit though.

[uteman]

Simple white vinegar worked very well indeed for me.
Tank was left for 2 - 3 weeks and was then shining inside compared to the rust that I started with.
You need to be patient but it worked great.

[posplayr]

CERTOL INTERNATIONAL USA/128-1 Muriatic Replacement Acid, 1-Gallon

relatively mild acid

https://www.amazon.com/CERTOL-INTERNATIONAL-USA-128-1-Replacement/dp/B000KKQ8LA/ref=sr_1_1?ie=UTF8&qid=1473314528&sr=8-1&keywords=acid+magic

[chuck hahn]

I would use a piece of heavier dog chain and shake that around a bit to beat the majority loose. Suck it out with a shop vac. Then do a quart of acetone and swish that around about every 15 minutes or so. Shake some sort of plug or the holes out of dowels or something as then acetone will eat the tape adhesive quickly. Lay the tank on each side for a while as well as on its top.

Change out the acetone after a while with fresh stuff and continue on .Point being let the acetone eat as much as it will eat. Use a flashlight and small inspection mirror to view inside and see how its going. Then do the vinegar or PREP AND ETCH from home depot or lowes for the derusting. Now it can be dried well and then tank liner applied.

[BentRod]

To deal with the rust I've used acid and smooth pea gravel many times. A guy I work with put me onto a redox method. He fills the tank with water and mixes in caustic soda. Then he dangles an electrode through the filter opening, without it touching the sides. The then connects his charger, (which is old and has no insulation or safety on it) to the tank and electrode, and lets the Red-Ox reaction take the rust off the tank. Seems to work pretty well except for the top of the tank.

[tkent02]

To deal with the rust I've used acid and smooth pea gravel many times. A guy I work with put me onto a redox method. He fills the tank with water and mixes in caustic soda. Then he dangles an electrode through the filter opening, without it touching the sides. The then connects his charger, (which is old and has no insulation or safety on it) to the tank and electrode, and lets the Red-Ox reaction take the rust off the tank. Seems to work pretty well except for the top of the tank.

Electrolysis, works well, will do all of the inside of the tank if you are patient and persistant. Never heard it being called Redox?

[BentRod]

Redox, short for Reduction / Oxidization, which are the principle reactions in a battery. It is also why stainless steel bolts in an aluminum marine engine result in bad news, and why zinc bolts can prevent rust from forming on an entire gear box or housing.

Electrolysis is a process name, or reverse plating?