Topic: Gas tank rust - opinions & testimonials needed

[greenjeans]

Ok, I have 2 rusty tanks that need cleaning etc.  After readiing many many posts, it seems to boil down to 2 options:
Kreme vs POR15.  Looks like the POR15 has a little bit better track record.    What is the acid/rust remover in the POR15? Does anybody know?  Is it muratic acid,  is it something I can buy at my local Home Deopt?   And since Honda tanks didn't come with any sealer, is it really necessary to coat the tanks after cleaning / rust removal (assuming they don't have pin holes etc)  Is the POR a more "permanent" option?

I have also read that some radiator shops will do the cleaning, but no shops in my general area will touch tanks anymore so that isn't an option.

Just trying to figure out which acid / rust remover works the best.... the Kreme kit & POR15 kit at my local dealer runs about 45 bucks.  By nature I'm somewhat of a cheapskate, If I can buy the same acid/cleaner for 15 bucks without all the marketing, that's what I'd like to do. 

Let the debate begin.  Thanks.

[Bob Wessner]

The POR-15 kit contains a cleaner/degreaser, acid (which is phosphoric acid) and then the sealer. I used steps #1 and #2 and skipped the sealer since the tank interior came out practically brand new looking. That was almost three years ago and it still looks good.

[mick750F]

   I used a $4 bottle of tile + grout cleaner, which was a dilute phosphoric acid solution, and loose nuts swished around in the tank. Rinsed well with water, then denatured alcohol and then filled with gas. I had no rust flashing. I saved the solution for future use. Similar results have been reported using molasses.

Mike

[gregimotis]

I rattled a bunch of bolts around in the tank first to loosen up the big flakes (not sure if this was needed, in hindsight), then used the Kreme acid prep,and skipped the tank liner step.  After that I changed the in-line filter a couple times and it's been golden for several thousand miles.
People say the tank can 'flash rust' if not lined and maybe it can, but it hasn't caused me any problems.



Can't speak to the technical stuff, but I took my time, did it right and it worked beautifully.

[Bikebuff]

Hi Greenjeans,

Funny you should ask about this, as I am going to be working on my tank this week.  I am planning to use molasses (the stuff you find in the baking aisle of your local grocery store)-Brer Rabbit unsulphured blackstrap molasses and a little hot water.  Check the FAQ section for the proper ratio of molasses to water.  From what I've read on this website, the chemical process is called chelation and apparently does quite a good job of removing rust.  Of course you'll need to rinse with water, then rinse with acetone and coat it temporarily with either diesel fuel or 2 stroke oil.  Or if you are going to use the tank straight away, you can fill with gas and go, assuming the rust isn't so deep it's actually eaten through the tank, in which you'll need to make the necessary repairs. 

From what others have said regarding this process, it is not adviseable to reuse the molasses for any baking of cookies later on 

[gpdesign]

+1 Molasses. I let mine soak (two large jars + water) for two weeks and it cleaned out all of the rust!

[Swede]

I have also had some luck with the molasses method seemed to do a pretty good job but you do need to let it sit in the tank for a few weeks.  There is another thread that has manuals that you can download at the bottom of the list of manuals there is a file titled Vintage Japanese Motorcycle Tech Tips: there is an article in there that talks about methods for tank cleaning.  http://www.sohc4.us/forums/index.php?topic=17788.0

[BobbyR]

I have also had some luck with the molasses method seemed to do a pretty good job but you do need to let it sit in the tank for a few weeks.  There is another thread that has manuals that you can download at the bottom of the list of manuals there is a file titled Vintage Japanese Motorcycle Tech Tips: there is an article in there that talks about methods for tank cleaning.  http://www.sohc4.us/forums/index.php?topic=17788.0

I would try the Molasses. It is non toxic, can't harm the paint or you. If it does not work, you can always go with the acid.

[greenjeans]

Molasses... now I've heard of everything... By nature, I'm not the most patiient person, so I think I'm going to try the phospheric acid route...  After I but the acid in it and rinse out do I need to neutralize it with something...chemistry class is a bit fuzzy in my old age. 

[Bob Wessner]

Molasses... now I've heard of everything... By nature, I'm not the most patient person, so I think I'm going to try the phosphoric acid route...  After I but the acid in it and rinse out do I need to neutralize it with something...chemistry class is a bit fuzzy in my old age. 

I don't know of it is necessary, but I did, with a solution of baking soda, sloshed it around then rinsed the dickens out of it and used a blow drier (shh, the wife still doesn't know ) to dry the interior.

Since then, when I need gas, I always fill-up, not just a gallon or two and keep it full with some stabilizer during the winter.

[BobbyR]

Molasses... now I've heard of everything... By nature, I'm not the most patient person, so I think I'm going to try the phosphoric acid route...  After I but the acid in it and rinse out do I need to neutralize it with something...chemistry class is a bit fuzzy in my old age. 

If you decide to go with the acid, remember, it eats everything including any weak spots of good metal. BobW is right, baking soda will neutralize the acid and is a very good idea. You can pour it in carefully, but getting it out may get sloppy. If it is neutral you have less chance of damaging anything. I would wear gloves and eye protection when you do this. Acids can be no joke.

[oldman prof]

I've found that using a length of chain links(smallish links) is easyer to get out than nuts & bits of metal,a wire hook and it all comes out in one go,no struggling to get that last whatever out ,hope it helps

[chung]

Perhaps I have been bleesed....... or I just bailed on the tanks that were that bad?

when I was younger, I would put a bunch of rocks in the tank with a bit of water and dance around the yard with it for a few days.
remove the rocks, rinse and hang a huge filter on it for a while. If it doesn't have holes in it and the trash isn't clogging the carbs then all is good Huh?

Damn,,,,,, did I say that outloud???

CRAP!!!!!!!    I used my real name too ahhhhhhhhhhhhh. LOLLOLLOL

For real, I have never treated a tank with any coating. I tried brick cleaning acid but that just put holes in the bottom. I refuse to use a POS tank, regardless of the paint. It is a Honda, they're plenty of organ donars.

That is the best way to go. On egay, you can get a tank for the cost of a couple 12paks of cheap ale?

Flush, Fill, leak, replace

[gregimotis]

My tank wasn't bad enough to have holes, it was just bad enough to clog the filter and carbs.  I put the bolts in, shook them around, and used a magnet on a stick to get the last couple out.  Then put the acid in - it didn't seem any more caustic than many household cleaners - drained it and rinsed with a pint or so of gasoline (insert warnings re: gasoline and sparks) and used a blow dryer to finish.

No problems, no new holes in the metal, no paint burned off, etc.  The only thing I did was remove the petcock and stop the hole with a cork - that made it easy to drain the tank.

I wouldn't worry about it too much:  Get the product and follow the directions.  If your tank starts leaking from new holes, that just confirms you needed a new one.  If it doesn't, then job well done; you've got a new story about your guerrilla-mechanicing skillz.

[BruceA cb550]

I used the POR-15 system and also used nuts and bolts to dislodge any stubborn rust.  Count the bolts so you know you have them all out when done.  My tank had sat for over 20 years and had alot of varnish and surface rust inside.  Inside of the tank looked brand new when done.  Looked so good I decided not to coat the inside, I figure thats just a potential future problem.  I'd use it again and its easy to do.

[Bob Wessner]

That's exactly what I did, bolts and all. The only thing I might add is that a member posted a suggestion (afterwards, of course) that rather than nuts/bolts, get a couple of short lengths of sash chain instead. It would be easier to fish them out. Made sense to me. If I have to clean a tank again, I plan to give it a try.

[kine8282]

I used Kreem on my 550's rusty tank without any problems. I think that its all about patience, I wanted to make sure that mine was well coated so it took me 3 days. I would recommend that when you you get to the liner bottle to only use 1/3 of the bottle first, let that coat your tank and let it dry and then use the rest to get a nice second layer especially in the middle rail inside the tank since thats the part that takes the most punishment from the gas nozzles.

just my 2 cents

[johnny-from-bel]

I used the bolds. Attachted the tank to the lathe and spun it at low revs (thread cutting speed) for half a day.
With the bolts came a bunch of rust.

Rinced the insite with paint thinner.
Then FEDOX rustsolvant
Then sealed with TAPOX

That was one year ago. Tank is still fine

[greenjeans]

I used the bolds. Attachted the tank to the lathe and spun it at low revs (thread cutting speed) for half a day.
With the bolts came a bunch of rust.

Rinced the insite with paint thinner.
Then FEDOX rustsolvant
Then sealed with TAPOX

That was one year ago. Tank is still fine

Hmmmm..... interesting, we have a lathe that is looking for some action.

[RyanLilly]

The molasses sounds like a safe route to take. I have not used it but based on responses it seems to work well.

 I have used a tank sealing kit on someones bike, but really some muriatic acid(hydrochloric acid) will take the rust right out, although the tank I did with the kit was rusted badly enough to have a few pinhole leaks at the seams. But for light or moderately rusted tank, the acid on its own, will do the trick. You should be able to buy it at any hardware store, it comes in quarts and gallons, and its cheap. Its commonly used to clean swimming pools and bricks. After you use it pour it into a bucket and slowly add baking soda until it stops fizzing, congratulations, you have made salt water. Pour bucket down drain.

The kits usually instruct you to rinse the tank with water after the acid, then rinse with acetone, I think the acetone helps remove the water, but the previously mentioned hair dryer method sounds like a cheaper way to remove water.

[chung]

Yea, don't forget the baking soda. Water alone will NOT kill the acid and then the acid kills the tank.

A nice sunny day will remove the water........ if you can wait long enough.

[Zane]

As a relatively new motorcycle rider, I've found that I get a lot of satisfaction from solving problems and doing many of the jobs my bike needs or wants done, myself.

When it came to my gas tank however, I took it to a place called Re-Nu and they zapped the inside clean with some sort of acid wash, and then they coated it inside.  That was just over a year ago.

I didn't do that though, until I had tried the nuts and bolts thing.  I found it worked very well, but I also found that I needed to keep the tank topped up with fuel if I planned on letting the bike sit for more than a day or so.  Otherwise "proto"-rust formed inside the thing.

I decided it was worth the expense to not have to worry about how much gas was in my tank for any other reason besides the operation of the engine.  So I had it cleaned and coated by a pro.  (I'd used the same company to do the inside of a vintage tractor gas tank about 8 years ago.  That tank is still spiffy inside.  Plus there's something I like about going to a small company that specializes - all Re-Nu does is clean and line gas tanks.  There's no other part of the business to carry them if they don't do great work.)

For me, that approach worked. 

I have respect and even admiration for those who choose to deal with their gas tank issue(s) in a different fashion.  Whatever works folks!

[Shadowjack1020]

Doing the fuel tank on my Gold Wing right now. Don't remember where I read it, but after I dropped in the abrasive (coupla boxes of drywall screws), I wrapped it in a blanket and stuck it in my clothes dryer. Braced it with pillows and turned the heat to "fluff". No gas fumes left in this one but I'd make sure if there had been to flush it out. After a couple of hours, I shook out a handful of rust dust, then went around a couple more hours to make sure. Not sure if I need to go any further with it--looks pretty clean, but don't know how fast it would rust up again.

[BobbyR]

Doing the fuel tank on my Gold Wing right now. Don't remember where I read it, but after I dropped in the abrasive (coupla boxes of drywall screws), I wrapped it in a blanket and stuck it in my clothes dryer. Braced it with pillows and turned the heat to "fluff". No gas fumes left in this one but I'd make sure if there had been to flush it out. After a couple of hours, I shook out a handful of rust dust, then went around a couple more hours to make sure. Not sure if I need to go any further with it--looks pretty clean, but don't know how fast it would rust up again.

You knocked off the loose rust which is a good thing. You should install a fuel filter to just pick up the stuff the srews may have missed. 

[scout18]

I have tried the muriatic acid route woked fine, Ace harware 4.99 a galllon. don't like working with it, gives me the willies. I do like the electrolysis method though.  No harmful effects and spiffy clean. I guess I would try the mollasses next just o see if it works. Living in the PNW you get some moisture in the air so tanks are always rusting if not taken care of.