Topic: Need to clean up tank, but don't need to coat it...

[Lumbee]

...greetings SOHC headz.  Picked up my new project this weekend, and now the fun begins.  Of course the PO did not drain any gas before putting it up 15 years ago, so carbs and gas tank are my first task.  My question is about the gas tank.  The tank looks to have a little surface rust inside, but nothing major.  I think I can get by without coating the inside.  However I would ike to clean the inside good as I think there may be some gas "gunk" in the very bottom of the tank.  What can I use to eat this stuff up?  Most of the older threads were on creaming a tank, but thats more than I need.

I'm looking for cheap remedies here, not anything pre-packaged.  Something for under $10 would be nice.  I read in one thread that acetone works good...will this get rid of the old gas/laquer in the bottom of the tank.

...I know how much you all like pics, so heres the project...76 550...

[78_SaltLick]

havent tried it yet but mollases seems to do the trick, $5 at grocery store. Do a search on mollases (i dont think thats how its spelled) theres whole threads on it and how it worked for them.

[Bob Wessner]

My tank looked similar to your description after 22 years of storage. I started out with the intentions of using the, three step, POR-15 kit, even purchased it. However, I only used the first two steps, the cleaner/degreaser and the phosphoric acid. After these, it looked brand new so I stopped there. It still looks the same after two years. I try to keep it topped off as much as possible, but other than that, not special care. While doing the degreasing and cleaning, I used a box of screws to knock off anything loose, it worked, but kind of pain to get the last few out. A member posted a better suggestion (after the fact of course  ) use a few short lengths of sash chain.

Though the POR kit was $30 or so, I would think if you could find the first two ingredients yourself you could duplicate the results. Just make sure you use phosphoric acid. You could try the Works for Rust, I think it is called, but again, get the one with phosphoric acid as it comes in a form using other acids as well I think.

[KilgoreTrout]

The Works toilet bowl cleaner

[Lumbee]

...OK, I found the posts on molasses...that sounds like the ticket...

[Dumbgumby]

My tank was the same way and the president of vjmc minnesota gave me some milkstone cleaner which is used to clean the parts used for milking cows I believe. It's mainly phosphoric acid but theres other stuff in there as well. You can buy it at fleet farm I think its like eight bucks or something and you mix it with 9 parts water, or whichever fills your tank up first. I used it, let it sit for about a day and a half dumped it out, then rinsed with acetone, then with a gas oil mix, then I topped off the tank with gas. The tank was badly rusted and now it looks brand new. Before using this I tried kreem and molasses both with bad results.
-Calvin

[Dumbgumby]

oh and it's reusable

[csendker]

I've used both the phos. acid and molassas. 

The phos. acid worked great on a somewhat rusty tank, but has a tendancy to 'flash rust' right after.  Have some acetone handy after you flush it out so you can get rid of any latent water.  Then either fill it with gas or a quick coat of kerosene/diesel to preserve.

I think the molassas worked good too, but it wasn't a fair test as I found that tank to be nothing more than formed paint.  It did get a lot of crud out, but the rust was so thick that there wasn't much left to work with.

In any event, pull the petcock before doing anything.  I found that the phos. acid will eat it alive. 

[tsflstb]

I took an old tank to the coin-op car wash and blasted it with the 'engine degreaser' setting.  It cleaned up really nice.  Just make sure to coat it with some light oil or fill it with gas after it's dry.  I put it on the shelf for a couple of weeks, and it rusted up inside.

That's a groovy looking bike -- very '70s.  You'll need to install some wood paneling and shag carpet in your garage...and boogy-woogy-oogie while you work on it.

[Lumbee]

You'll need to install some wood paneling and shag carpet in your garage...and boogy-woogy-oogie while you work on it.

Yea baby, Yea!!!! 

[ken74-550K0]

You might want to try a couple of ounces of citric acid dissolved in a gallon of hot water.  Throw in a few handfuls of nuts and bolts and shake vigoursly.  Rinse the tank immediately with some mild soapy water, then again with clean water.  Dry the tank thoroughly with a heat gun or hair dryer.  As soon as it's dry, mist the inside of the tank with WD 40.

I used this process on my tank - it left the inside of the tank a nice slightly etched medium gray color.  The tank has been on the bike for about a year without any trouble.

A bottle of citric acid (found in the canning supplies section of a grocery store) costs less than $3 and is much less toxic than some other alternatives.

[Bob Wessner]

In any event, pull the petcock before doing anything.

That was assumed, but I should have mentioned it also. Sorry about that.

[KilgoreTrout]

The molassases from the grocery store didn't work as great as I thought it would. To be honest I first used "The Works" which took off 95% of the rust. Then I did the molasses thing and i honestly didn't see that much if any difference. I think the #$%* at the grocery store stuff was a waste of money. I would be interested in trying the molasses from a Feed & Grain store though since it's supposed to be stronger or perhaps next time spring for the extra $15 and buy the 3-step #$%*.

[csendker]

The stuff at the grocery store is cane sugar based, fit for consumption by us humans.  The stuff at the feed & grain store is corn? based - or something other.  I guess cows may love the stuff, but not us humans.  There's more collagen's or whatever it is that attacks the rust in the feed-variety, so it's supposed to work better.  I also think the phos. acid will work better, but it's drawbacks are environmental, flash rust, stronger - may eat too much, etc.  I suppose it depends on the extent of cleaning that is required and/or you want.