Topic: De-Rusting a tank with "The Works" Toilet cleaner -Very Easy!

[norom]

I wouldn't recommend any off brand toilet cleaners I did this with my bike in the summer. I got some off brand stuff from a local Bimart and let it soak in the tank for awhile in the warm sun. I cleaned it out, dried it and still quite a bit of rust remained I made sure to be cautious of any flash rust as well. I eventually went to a radiator shop and had them boil out and coat my tank looks great now.

[PurduePete]

I just did a similar procedure with my CB500 restore project. Here are some pictures of what I started and ended up with. At the bottom I went into some detail about the chemistry of how "The Works" actually does its work. Not much, only a paragraph of reading. But using just the works without water does not actually help, "The Works" mixed with water is a Strong acid where as "The Works" alone is only an acid. As stated directly above use only the real brand, got mine at Wal-Mart for $1.22 while the off brands were even a bit more. Look for Hydrogen Chloride and that tells you that you got what you need.


What I started with:


I used 4 gallons of white Vinegar with 1.5 cups of salt per 1 gallon (produces a very very low concentrate HCl acid, which is what muriatic acid is), it then soaked for 5 full days. The pictures is also after shaking screws around in half of the vinegar solution before pouring the rest out.


This is 10 minutes after using the works, as you can see it started surface rusting. The surface rust is not a big deal because I am using Ospho to try and turn the rust into a type of lining.


The thing about "The Works" is that it does not contain an acid as we typically think of it. It contains Hydrogen Chloride. When it contacts the atmosphere it does turn to HCl acid but it NEEDS to be combined with WATER to actually become HCl acid in a strong usable form. This is not to say that "The Works" does not work without water but it does work better. So for those of you that are saying that you are going to use the works full strength or have used it at full strength, this is not the case. Combine with water for full strength. I mixed 2 bottles of "The Works" with 2 gallon of water and this worked very well for me. Wear a mask and gloves as the fumes are really not good to mix in.

While I may be younger than most I am in Mechanical Engineering Technology at Purdue and have taken way too much Chemistry. I do not claim to be an expert though, far from it. I also do not want to upset anyone. This is from the hours of research that I have done before actually trying anything on my gas tank other than Vinegar. Also had a lecture on HCl a few times and worked with it, super nasty stuff and we always used a fume hood. Why I was nervous to do it myself at home. Here is a link to a Wiki article explaining it in better detail than I have. http://en.wikipedia.org/wiki/Hydrogen_chloride

Hope that this helps anyone that is interested in the Chemistry behind cleaning out your gas tank. Good Luck 

[Really?]

Nice write up!

[lucky]

I just used the Caswell gas tank liner with white colorant which I purchased seperately at TAP plastics.

It came out very white and glassy. The tank was rusty (light rust) inside.
Caswell said the rust just gives the liner a better tooth.

I was very pleased with the outcome and will use it again.
The only thing is mix the entire kit and keep turning the tank around until it starts to set up. At first I mixed up half of the kit as per their instructions but could see that it would be set up before I ever got all the surfaces covered by rolling it around,so i immediately mixed up the rest of the kit and added it in.
There was no left over material in my 5 gallon 1978 CB750 tank.

[lucky]

Phosphoric acid is also known as Os-Pho (tradename), correct?  It leaves a white residue and can damage paint... 

I'm not sure how someone could trademark phosphoric acid - it's a pretty common chemical?

I would think ANY acid will damage paint - why would you be worried much about that with cleaning the inside of the gas tank? I mean, I assume you would plug off the holes when cleaning the inside and generally be careful, right?

Also, as per the instructions, you dilute it and it takes a while and sporadic agitation to work but wow does it work. Left my various tanks' insides just spotless with a dull grey coat of zinc-phosphate. I cleaned a CB750 DOHC tank for my friend that had really nice paint and it was fine - no spotting or harm what so ever, though I would rinse the outside of the tank off with water between agitations (allowing my little arms to rest from the work out. .  .lol)

I cleaned my CB500 tank almost 3 years ago and the inside is still spotless (though, I also always keep the tank full before it sits and put a shot of Marvel Mystery Oil in the tank with each fill-up, especially in our rainy winter weather, to prevent any tank rust.)

After cleaning with phosphoric acid then rinse with water.
Finally rinse with acetone to get any water out.

Acetone will absorb 3 times more water than MEK.

Coat the inside of the tank.

[PurduePete]

According to the Ospho direction it says to let it dry over night without rinsing. That is what I am trying. After a few hours sitting in the bathroom with the fan going it has not started to surface rust at all. It really looks pretty good. The metal is a much darker color and I hope will not rust again. I poured the Ospho into a spray bottle so that I didn't contaminate the rest of the bottle (only used about half to coat the inside of the tank. Plan to use some of the Ospho to treat the bottom of my gas tank as well and then clear coat it so it doesn't rust until I can paint it later down the road. It was pretty rusty, already sanded it down and coated it with light oil.

If the Ospho does not work then I will be using a POR-15 Kit to seal up the tank. So far so good though, it really helped dissolve the rust pretty well.

As the above poster suggested to use Acetone as it absorbs more water so I gave it a go. Ate all of the Ospho off. I am trying to use the Phosphoric Acid to leave Iron Phosphate on the tank walls so that it doesn't rust again, but the Acetone just got rid of it all making me start from the beginning again. No big deal if you just fill it up with gas but I didn't. Just figured I'd say this so help someone else out if they try the same thing.

[ncstatecamp]

Anybody try reverse electrolysis? Then a coat of copper plating immediately after?

[saxamaphone]

One question I have is will "The Works" and phosphoric acid (Prep and Etch) ruin the gas cap seal? 

Have those of you that have tried these techniques been taking off the gas cap and sealing the top some other way?  Or putting plastic over the hole before closing the gas cap?

This is a lot cheaper than using Evapo-rust like I did here http://forums.sohc4.net/index.php?topic=110414.msg1239553#msg1239553

[Bankerdanny]

I did this with my '77, which had about 2/3 of a tank of 25 year old gas in it when I bought it (it was probably a full tank when parked).

It did a very nice job of cleaning the inside of the tank, but take care to protect your paint as I had some peeling issues in the area around the cap under the cover flap.

Overall though this is a method that I would (and have) recommend.

[WhyNot2]

And baking soda and water mix works wonders on heart burn too.......

Ask me how I know..........................read the box and it will tell you.

[SoyBoySigh]

How about doing just the rear seam by stripping the paint down and putting some braze and flux in it then heating from the outside? Flux would need a lot of rinsing, but there's gotta be a mild temp solder bronze for steel that's impervious to gas. Probably what they use in original assembly in order to back up the spot-welding!

[slyguy]

Wow, nice write-ups, I need to do this on my tank, prolly go with the H-D phosphorous/etch...I do have a couple simple questions from my simple mind lol. Leave cap on top for sealing and/or use plastic or tape? and petcock hole? any need for concern of pressure buildup? Thanks!

[4bangin]

I had time today to clean out my tank for my 73' CB500k, I don't think it was to bad but better safe than sorry. I used the basic formula for success.
1. Drained and dried tank overnight.

2. Used a old bike chain to knock junk loose.

3. Blew out the rest with compressed air. Masked gas cap area and plugged petcock area.

4. Poured the full bottle of Work's cleaner into tank with about 1/2 cup warm water to dilute a little to add volume.

5. Drained and Rinsed with Baking soda and warm water, then spray a hose knock loose all the sludge.

6. Drained and dried w/ compressed air, then added NAPTHA cleaner to soak up the excess water.

7. Dried and then added a couple of oz. of Mystery oil to coat till next week, waiting on a new fuel Petcock.

I was very pleased with the results, and relieved that it is done. Next is the carb rebuild kits and a little tuning. I am very thankful for all the information shared on this forum and would like to tell everyone thank you for your time and efforts on keeping these bikes on the road!

[USCG_C130]

thanks for the tip here the real work worked great that 20% HCL was awesome and heres what came out of my tank. keep in mind a few months ago i did the POR cleaning system and never got the liner  or any oil in it, so it rusted again, the works went in almost clear and came out like this.

i bought the POR kit but after reading all the stories of failing liners i decided against it and  just used "the works" and ATF method and getting it ready for paint and then ill be sure to always leave it topped off this clean tank and  2 fuel filter i think ill be just fine and never have to worry about failing liners clogging up my fuel system.


thanks again

[Liesuresuitlarry]

I realize this is pretty old, the thread i mean, I found it looking up klean strip metal prep & etch because I was considering it to clean this tank I am working on.  i have tried a lot of other things and they all flash rust pretty quick, even with the oil coat that was mentioned already.   Vinegar really does work, apple cider type works best.    But i was looking real hard at this tank. it has baffels. It's a Honda CVCC  tank. not a bike tank.  i do have many Bikes though that I play with so I have had all that sort of experience in tank cleaning already, that was sort of what interested me in this club and this forum in particular.  my Bikes ( over 20 ) are are nearly all single cylinder thumpers.  all 50's 60's and 70's.

   anyway, LOL     I tested this metal prep & etch stuff because i was looking for something cheaper to use with the Por 15 product so it didn't cost so much.    it worked very well, in fact i think it worked maybe even a little better than the marine clean which is REALLY high dollar compared to Kleen strips product.   

  so when it cam to this tank , the honda CVCC 1978 tank.   after trying so many other things to get this super rare and nasty dirty sob clean. I decided maybe I should do it to this.      I tested this stuff where it would be visible to me, i cut away a section of a gallon jug and dropped the old tow chain section I was using as ballast to knock the big rusty stuff loose from inside the tank.  it was equally rusty as my tank.     I poured about 8 )z in and stirred it up, that chain is spotless right now and I hung it up outside with nothing on it after i rinsed it down and its not rusting.

    I have my tank strapped to a hand cart wheel ( Dolly ) right now,  with half a gallon of the the metal prep in it, I check it a bit ago.

  after talking with the por 15 guys and reading through their PDF files I found that even they only recommend coating a tank when it is the absolute last resort.  i have no holes so I am just going to use this tank when the etch is done.   

  im going to rinse it out and dry it with a heat gun and bolt the sob back on the car and fill it up.    I dropped the sending unit in this stuff ( dismantled ) and it not only cleaned it from a solidly Locked up ball of rust and dried up old gas, it freed up the resistor and with a slight scrub with a fingernail brush it works like brand new!  no joke.  6 Ohm is full 106 Ohm is bone dry.

  i don't know how long the coating of zinc stays on the inside of the tank but the OEM didn't have any coating at all and its lasted all these years so I think this this super cheap metal prep & etch is the way to go.  by cheap I mean, a gallon is at most 15 bucks, to do a bike tank you might need 4 OZ to shake around in there and let it set on each side.     so I have only used 1/2 a gallon on this car tank which was extreme dirty.   I can knock out a few bike tanks with the remainder,  super bargain if you ask me. 

  also, the fumes are minimal, i didn't use gloves but I was careful not to get it on me. seems way more user friendly and the flash rust inhibitor is the real bonus.