Bridgestone Motorcycle Parts Discussion Board

Bridgestone Tech Talk => How To => Topic started by: Hap on April 16, 2011, 11:29:09 AM

Title: cleaning rusty gas tank
Post by: Hap on April 16, 2011, 11:29:09 AM
You can find all kinds of comments, products, procedures on the web to clean a rusty tank which will all drive you crazy after a while. I decided that I want to deal with something that is non toxic since I am kind of a slob and dont want to ruin any paint on the tank or wear protective gloves, etc. I bought a gallon of EVAPO RUST at pep boys for 25.00 and it worked great. It worked so well that I dont even need to seal the tank after soaking with the EVAPO RUST. I just plan on keeping the tank full of gas so rust does not have a chance to start. Before you use the EVAPO RUST you have to prep the tank. Mine was a Sport 90. Remove the tank from the bike and take off the petcock. My fuel line which goes under the tank and connects to both sides was so rusty they were clogged. I used some gunk engine cleaner sprayed on a large heavy duty safety pin and picked away through the little nozzles until they could go through into the tank. That took a while but you want to get all that crap out so you can replace the fuel line that connects to both sides when you are finished. Now for the tank. I used HOT WATER and DAWN detergent along with 15 large bolts and 5 large nuts put into the tank. Take an inventory of the number of bolts and nuts you put in the tank and write it down. Trust me on this! You want to make sure they all come out because they could wedge them selves periodically. I put the gas cap on the tank and my hand over the petcock hole and shook the bolts around to loosen up all the caked on rust. Empty the water out into a large clear or white plastic bin so you can monitor what comes out. Keep on filling, shaking, rinsing, draining, etc, until you can hardly get any more flakes or debris. This takes a long time, It took me about 20 fill ups and three hours of work until I was satisfied to go to the EVAPO RUST. You should have little or no flakes (only a slight amount of small specks or debris) before starting with the EVAPO RUST. Plug up the petcock hole. I wrapped plumbers thread tape around the threads of the petcock hole to protect the threads and then heavy duty packaging tape around the whole petcock hole and then a small hose clamp around the tape to close it tightly. It leaked a very small amount but that is ok since you will be placing the tank on top of the plastic bin. Place the fuel line back onto the each side of the small nozzles of the tank so nothing leaks now on the bottom of the tank. Place the tank on top of the plastic bin and dump the whole gallon of EVAPO RUST into the tank. Cap the tank and allow to sit overnight. Next day turn the tank over and allow to sit overnight. Next day turn tank on one side and allow to sit overnight, Turn tank on other side and allow to sit over night. The time all depends on how rusty your tank is. I let it sit at the bottom another night and on the top another night so my total soak time was 6 nights! When you are satisfied that it is clean, drain the EVAPO RUST through a fine screened filter so you can save it and put in back into the original container. Rinse the tank out with water using your highest pressure stream from your garden hose. I did this a couple of times and shook all water out. Then cover up the petcock hole and bottom hose again and put the EVAPO RUST back into the tank and shake it all around. You do this to prevent flash rusting of the interior surfaces of the tank. Drain the EVAPO RUST back into the original container. Now you need to just air dry. I used my air compressor and my wifes hair dryer (dont tell her!), or you could leave a fan blowing on the tank. Make sure all holes are open and the tank is completely dry before re installing. You can see the before and after pictures. Amazing! Total cost was 25 bucks and you can use the EVAPO RUST to clean other parts. No need for harsh chemicals, tank sealers, multi-step processes, etc...Good Luck!     
Title: Re: cleaning rusty gas tank
Post by: Jeff Bar on April 17, 2011, 12:53:41 PM
HAP: Great story, lots of good information, many thanks Jeff Bar
Title: Re: cleaning rusty gas tank
Post by: mhanahan on November 10, 2011, 01:42:18 AM
That's exactly what I was planning on using! Glad someone has tried it with good results. I have used EvapoRust before on a pre 1950 ratchet I found sitting in a barn, cleaned it perfectly and the wrench works now...great stuff!
Title: Re: cleaning rusty gas tank
Post by: edward on November 10, 2011, 10:31:32 AM
You Tube has similar videos on the subject. One used aquarium gravel to completely clean the inside of the tank. Another use electrolosis (really simple too) I need to know how to strip the outside, or if I should just cut my looses and buy one from Richard. If he has them in stock.
Title: Re: cleaning rusty gas tank
Post by: mhanahan on November 10, 2011, 10:57:03 PM
You Tube has similar videos on the subject. One used aquarium gravel to completely clean the inside of the tank. Another use electrolosis (really simple too) I need to know how to strip the outside, or if I should just cut my looses and buy one from Richard. If he has them in stock.

Maybe sand/media blast it?
Title: Re: cleaning rusty gas tank
Post by: cwesty0 on November 11, 2011, 05:18:19 AM
I used CLR in the tank I did. A quart sized jug poured in and then filled with water to the top. Let it set for 24 hours and it came out great.  I didn't have the real heavy scaley and flakey rust though.  Somewhere on my pictures is a pic or 2 of the tank afterwards.

Craig
Title: Re: cleaning rusty gas tank
Post by: paul25g on November 11, 2011, 07:53:06 AM
I tried electrolosis using a battery charger and had pretty good results....I think there are other posts on the forum about this method.  Thanks!
Title: Re: cleaning rusty gas tank
Post by: OldSwartout on November 11, 2011, 09:05:47 AM
You Tube has similar videos on the subject. One used aquarium gravel to completely clean the inside of the tank. Another use electrolosis (really simple too) I need to know how to strip the outside, or if I should just cut my looses and buy one from Richard. If he has them in stock.

Maybe sand/media blast it?

I'm pretty certain all the new gas tanks are gone, except for the random NOS that shows up on E-Bay occasionally. 

Yes, sand or bead blasting works on the outside, or just paint stripper and steel wool or Scotchbrite. 

DO NOT sand or bead blast the outside if you're going to rechrome the tank. All the texture left from the blasting will have to be ground/sanded/polished out - hours of extra work and expense.  If rechroming, you can strip the paint, but let your plating source clean it up from there.
Title: Re: cleaning rusty gas tank
Post by: Bikenstein on December 04, 2012, 09:21:18 AM
Yeah thanks for the info Hap. I think I'm gonna "rig a jig" to hold my tanks and use my cement mixer for initial rust removal. Or maybe wrap em in bubble wrap and duct tape.
Title: Re: cleaning rusty gas tank
Post by: Mopar5426 on December 04, 2012, 09:55:44 PM
  I Took A Rotaricery Motor For A Barbaque Grill And Made Mounts For The Different Tanks  Also Put Bolts In It Let It Turn For A Few Hours To Losen The Rust     The Post Has Been Done Before   I Used Battery Acid Not Fun Too Work With But I Tride The Rust Stuff  Nothing Worked As Good As The Acid  Just Dont Leave In Too Long GENE
Title: Re: cleaning rusty gas tank
Post by: reed on December 06, 2012, 08:48:26 AM
I still use milkstone in my fuel tanks i leave it in for about 12 hours and it cleans out the tank nicely.
Then i put baking soda with water in the tank for about 2 hours, clean the tank out spray WD-40 in
Tank and then  i am done ready for a cup of tea.
Thanks.
Steve.
Title: Re: cleaning rusty gas tank
Post by: Bikenstein on December 06, 2012, 08:53:45 AM
So, a final rinse of the tank with a cup of tea? ;D cold or hot?
Title: Re: cleaning rusty gas tank
Post by: reed on December 06, 2012, 08:58:15 AM
David,
Only HOT TEA mate!!
Thanks.
Steve.
Title: Re: cleaning rusty gas tank
Post by: Bikenstein on December 06, 2012, 09:01:39 AM
The tea would probably deter rust better than the WD-40 :)
Title: Re: cleaning rusty gas tank
Post by: reed on December 06, 2012, 09:07:41 AM
David.
You are right!!
Thanks.
Steve.
Title: Re: cleaning rusty gas tank
Post by: slawsonb on July 10, 2013, 07:34:45 PM
I bought a gallon of EVAPO RUST based on this thread with intentions of using it to clean my tank. I got so busy derusting stuff that had needed it for years that I have consumed my tank cleaner....LOL. This stuff really works...off to buy more!
...bert
Title: Re: cleaning rusty gas tank
Post by: moonpup on July 10, 2013, 07:39:33 PM
Bert, you should be able to get it for less $$$ on Amazon, that is of course if you're in no hurry.
Title: Re: cleaning rusty gas tank
Post by: slawsonb on July 10, 2013, 11:43:47 PM
will check it out...thanks moonpup
...bert
Title: Re: cleaning rusty gas tank
Post by: slawsonb on July 11, 2013, 12:56:28 PM
O'Reilly Auto Parts seems to have the best price (at least here in Tucson) on EVAPO RUST ($22.99 + tax vs $31.92 w/ shipping on Amazon). Go figure...
...bert
Title: Re: cleaning rusty gas tank
Post by: moonpup on July 11, 2013, 01:10:31 PM
Go figure is right.... when I bought the stuff a year ago, Amazon was way cheaper than the local outlets. But NOOOOO, as soon as I try to give some friendly help, it's the dang opposite!  :o   ;D ;D ;D
Title: Re: cleaning rusty gas tank
Post by: slawsonb on July 11, 2013, 01:18:18 PM
Definitely appreciate the friendly help...I am always keen to save a buck... ;D
...bert
Title: Re: cleaning rusty gas tank
Post by: grundlegrabber on July 11, 2013, 10:09:19 PM
I've been using the evapo-rust for a few years with great results. Also have used the electrolysis method on an extremely rusty Hodaka tank. No matter what you do it's time consuming, but it does work!
Title: Re: cleaning rusty gas tank
Post by: slawsonb on July 11, 2013, 10:27:12 PM
My plan, once I get some more magic rust remover, is to follow the Hap recipe. The replacement tank requiring the derusting process is not too bad. I just regret that I neglected the original long enough that it rusted through. Lesson learned...GTRs must be ridden frequently!
...bert
Title: Re: cleaning rusty gas tank
Post by: old smokey on July 12, 2013, 10:43:16 AM
and ridden only during daylight hours!  8)