Bridgestone Motorcycle Parts Discussion Board

Bridgestone Tech Talk => Restoration => Topic started by: Australian Guy on February 28, 2009, 11:06:25 PM

Title: Internal corrision of fuel tank
Post by: Australian Guy on February 28, 2009, 11:06:25 PM
Hi guys

My first post here and my first bike restoration. Could anyone give me tips of removing internal rust from a fuel tank ?

cheers
Paul
Title: Re: Internal corrision of fuel tank
Post by: Australian Guy on March 01, 2009, 05:59:28 AM
its ok I found this article of google

http://www.mopedarmy.com/wiki/Removing_rust_from_a_gas_tank (http://www.mopedarmy.com/wiki/Removing_rust_from_a_gas_tank)

Title: Re: Internal corrision of fuel tank
Post by: czmike on March 01, 2009, 08:23:21 PM

Hi Paul,


Nice to see another Australian Guy join this Forum.
I have a GTR I am restoring and I live in Melbourne.
What have you got and where are you mate?

I de-rust tanks and other parts using a molasses/water mixture which is quite a common, cheap and safe method used by many vehicle restorers. It does take a little more time though than the nasty acids & things.


Best Regards,

Mike Munday
Title: Re: Internal corrision of fuel tank
Post by: OldSwartout on March 01, 2009, 10:38:32 PM
its ok I found this article of google

http://www.mopedarmy.com/wiki/Removing_rust_from_a_gas_tank (http://www.mopedarmy.com/wiki/Removing_rust_from_a_gas_tank)



The battery and washing soda method described in that link works well.  I've used it on several tanks.  It leaves a nice phosphate-treated surface that resists rust and makes for good adhesion of a coating if you use one.  I haven't coated mine, but they have hardly rusted in several years.  That's also a good method to de-rust other items, also.  You can dispose of the solution down the drain when done as it isn't harmful.

Here's a link to the electrolysis process that has some photos: http://www.smokeriders.com/Tech/html/electrolysis.html (http://www.smokeriders.com/Tech/html/electrolysis.html)
Title: Re: Internal corrision of fuel tank
Post by: Jeff Bar on March 13, 2009, 11:28:44 AM
I have used the three step process from Kreem, it worked great.

Jeff Bar
Title: Re: Internal corrision of fuel tank
Post by: old smokey on March 14, 2009, 04:19:08 PM
I bought the 3 part Kreem process, but haven't used it yet. Sounds like a time consuming process. The owner of the used shop here said he uses "milkstone" which can be bought at a local farm supply store. Suggests mixing it with 4 parts water to 1 part milkstone. Think I'll try that before using the Kreem (if still required).
Title: Re: Internal corrision of fuel tank
Post by: Jeff Bar on March 18, 2009, 11:31:46 AM
The Kreem three part kit does that some time, but if you want a really nice job........
Jeff Bar
Title: some results
Post by: old smokey on May 25, 2009, 06:50:41 PM
I will start a new thread once I get the photos downloaded to show the finished result.
My camera batteries were dead so rather than go to town to buy new, I went ahead and started with cleaning the rust out of my tank. I used "Milkhouse Brand" Milkstone remover and acid rinse. It's made for dairy operations.
It contains phosphoric acid at 56%. I left it with water sitting in my tank for 24 hours. When I poured it out I couldn't believe how well it worked. It practically looks like a new tank inside. If you rated a new tank at 10 and a tank with rust holes starting to go thru a 0, I'd rate mine as starting at a 5. Now I'd call mine a 9.5
The Milkhouse stuff cost $10.99 for the gallon.
As I said, I'll start a fresh thread when photos are downloaded (the camera batteries were recharged before the tank was done). But my weekend was pretty productive!  :)
I have a spare non-chromed gas tank that has worse rust inside. Maybe when I feel rich enough to spend $11 for no reason I'll try doing that tank too (and take pictures first)!
Title: Re: Internal corrision of fuel tank
Post by: Dave K on May 26, 2009, 01:29:06 PM
Maybe I missed it. How does this work with tanks that still have good paint and chrome on the outside? Will it harm these finishes and if not were you able to protect the outside finish from damage?
Title: which method?
Post by: old smokey on May 26, 2009, 09:56:37 PM
Not sure which method you were interested in trying. For the phosphoric acid and water method, I found a rubber plug that fit in the petcock hole in the bottom. Then carefully add the acid to minimize spilling on the outside. After sitting for a day, I just pulled the plug out.
Title: Re: Internal corrision of fuel tank
Post by: rocketman on May 27, 2009, 09:04:36 AM
I'm sure all the methods of rust and corrosion removal being discussed are effective thru the chemical reaction that they cause. If you do spill the solution on the outside finished surfaces of the tank and were to leave it,the chemicals would eventually etch the surface. It sounds like the molasses mixture is a milder acidic base and would therefore etch much slower than other acids like the product that "Kreem" supplies in thier kits. They warn you against surface damage in their instructions. A good coat of wax will provide your first line of defense. Then quickly rinse anything that gets on the outside with plenty of water.  And of course,use safety goggles and gloves when doing anything involving acids. Mark.
Title: Re: Internal corrision of fuel tank
Post by: Dave K on May 27, 2009, 01:52:09 PM
Did you totally fill the tank or just put in a few quarts and slosh it around?
Title: Internal corrosion
Post by: old smokey on May 27, 2009, 06:13:46 PM
Using the acid I did, I put about 2 gallons of water in first, then the 1 gallon of acid solution, then topped it full with water.
Title: Re: Internal corrision of fuel tank
Post by: IrishWheelee on December 27, 2014, 09:17:38 AM
Hi

I used the Kreem 3 part system after painting my tank being careful to follow the instructions to the letter. It looked great until a month ago, however I opened the tank yesterday and the liner had cracked and is ready to flake off. I am very dissappointed as it had great reviews. What is the best sealer remover and best sealer any of you guys have used? I would really appreciate your comments

Pat
Title: Re: Internal corrision of fuel tank
Post by: CL-100 on December 27, 2014, 12:42:14 PM
I've heard of people removing Kreem with MEK or acetone and unfortunately you're not the first person that's experienced this problem.   Personally, I've always been a fan of Red Kote epoxy tank liner.  It will also permanently seal tiny pin holes in your tank.  I have a '76 GoldWing with a tank I lined about 5 years ago and it still looks great.  I always remove rust first with Evaporust liquid before applying the liner.  I've found the best price for the Red Kote on eBay.  Good Luck. 
Title: Re: Internal corrision of fuel tank
Post by: bsforever on December 27, 2014, 02:02:27 PM
CL.... you are right with the acetone to remove KREEM from the tank ( that is what i used for mine ) but also ( as i learned the hard way ) it WILL REMOVE PAINT from your tank as well. I did switch to using Red Kote ( but got a different tank as well ),it had a better result than the KREEM. As in Irishes case, mine peeled and lifted away from the metal inside the tank and had to remove the KREEM with acetone.
Title: Re: Internal corrision of fuel tank
Post by: CL-100 on December 27, 2014, 02:31:01 PM
I keep hearing stories about Kreem cracking and peeling.  I originally stumbled across Red Kote in an internet video and learned that it was being used to seal radiators when someone realized how well it works on fuel tanks.  I've never used acetone or MEK to any great degree and haven't used it around paint.  I've recently used Red Kote on a BS100 GP tank that was NOS but poorly stored.  I removed all the rust which uncovered a pin hole in the lower front seam.  I sent it out to Brown's for chroming and lined it with Red Kote when I got it back and the pin hole is no longer an issue.  I had removed all the old paint before I sent it out for chroming and now I'm trying to find a match for the blue paint they used in '69.

bsforever, Thanks for confirming that acetone will remove the Kreem.
Title: Re: Internal corrision of fuel tank
Post by: grundlegrabber on December 27, 2014, 08:06:18 PM
I've used Caswell Plating's tank sealer, as well as POR-15. The caswell sealer seems to be the best. It's a clear epoxy that is ethanol-safe, will not be compromised by modern fuels. Somewhat thick, coats very nicely, and looks great when done. The POR-15 is silvery looking, not quite as thick as the Caswell so it was a little more difficult to get a good even coating and the finished surface is not quite as smooth. I've heard POR-15 can be affected by ethanol, but I've not had a problem with it so far. Used it in a Hodaka tank that was severely rusted, worse than anything I've ever seen. Never liked Kreem, never heard anything good about it, it's not ethanol-safe, and I've seen many tanks ruined by bad Kreem jobs.
Title: Re: Internal corrision of fuel tank
Post by: CL-100 on December 28, 2014, 07:52:46 AM
The Caswell sounds like the Red Kote...not affected by ethanol or any known additives in today's fuel.  I like the idea that it's clear.  I may take a look at that next time.  I finally found a fuel station nearby that sells non-ethanol gas and have slowly worked this fuel into my vintage bikes.  In my one modern-day bike I still use regular fuel but add an additive to combat the ill effects of the ethanol.  Good information, thanks.
Title: Re: Internal corrision of fuel tank
Post by: coxy on December 30, 2014, 02:11:30 PM
rearrange the letters from kreem it spells crap !
Title: Re: Internal corrision of fuel tank
Post by: mike1948 on December 11, 2022, 02:44:37 AM
I used Caswell sealer on a steel tank and my Bsa Victor alloy one, 4 years ago- 2018 - and is still in fine shape, using unleaded fuel, but no ethenol in it.
Mike
Title: Re: Internal corrision of fuel tank
Post by: Chibi62 on January 10, 2023, 10:20:11 AM
I use POR15 tank sealer. It works extremely well. Superior sealing that when dried creates a leak proof surface. Excellent for tank restorations or to cover over internal rusty tank surfaces. I have found that one can will coat several tanks. It goes a long way. Simple way to rid yourself of tank related leaks, or rust.

Kevin