Topic: Best solution for light rust inside tank?

[1977_cb550k]

Hi folks, I've got some light rust inside my '77 model CB550 tank. It's getting through to the (stock) carby's and occasionally the float bowls get stuck. I want to fix the cause and not keep treating the symptom.

What's the best way to deal with it?

I've heard a couple of different ways:
1. Use Metal Rescue (how do you apply it?)
2. Reseal the tank inner with some sort of Marine epoxy (seems the more expensive route)

What's best? What's worked for you? Advice and tips appreciated.

Jason.

[Deltarider]

The only thing I ever did, was throw a handful of balancer lead in the empty tank, then shake it for a couple of minutes and rinse the tank afterwards with diesel. I would start with that. Using the stock, now 42 year old, tankfilter I had no other problems than the occasional somewhat sticking float valve needle after hibernation. Extra inline fuelfilters however have proved to compromise fuel flow on multiple occasions.

[RustyF]

+1 for metal rescue.  I used 2 bottles and 2 gallons of distilled water.  let it sit upright 1 day, on each side 1 day and upside down 1 day.  Then drained & flushed tank with distilled water then gas.  Installed new petcock and it is all good.  I was really impressed with the result and what came out of the tank.

[slikwilli420]

Extra inline fuelfilters however have proved to compromise fuel flow on multiple occasions.

And yet on an 80hp race bike, no issues running along at WFO.

[Imago]

I use a jug of apple cider vinegar and a short piece of light chain. Duct tape up filler and bung and slosh vigorously for a few days. Looks like new.

Be sure to rinse it well right after and fill with fresh fuel, (and a bit of 2 stroke oil never hurts)  to avoid flash rusting after it's cleaned.

[Deltarider]

Extra inline fuelfilters however have proved to compromise fuel flow on multiple occasions.

And yet on an 80hp race bike, no issues running along at WFO.

Try it on the model we're talking about here... 

[slikwilli420]

Extra inline fuelfilters however have proved to compromise fuel flow on multiple occasions.

And yet on an 80hp race bike, no issues running along at WFO.

Try it on the model we're talking about here... 

Why would that matter here? 4 cylinder honda of similar vintage. You have cried about fuel filters being the devil on every thread about fuel and fuel tanks. At most we are comparing Gala to Macintosh, hardly apples and oranges as you suggest.

[Deltarider]

FYI, I'm not the only one here that had nothing but trouble with inline fuel filters on a CB500 or 550. We can discuss all kinds of possibilities such as the minimal column height gravity has to exercise its force on these models, the limited space there is to fit one, often a cause for kinking, the filters position behind a pretty hot engine block, and so on, and so on... decades ago I gave up analyzing and just removed them. Never had any problems thereafter*. As safety is a concern here - I myself had a narrow escape -, I feel it is my duty to warn CB500 and CB550 owners. There's more. In those years I used to ride downsouth over the German Autobahns, maintaning cruising speeds of around 140 km/h and it makes you sick when your engine starts to stutter and then have to ask yourself what damage those filters can have caused... Maybe I had been riding lean for too long... But, if you have any doubt on my report, why not put it to the test on a CB500 or CB550 yourself? I have to warn you, make the test period weeks rather than days. Then we talk.
*As a matter of fact, neither did I have a problem before I fitted them. Mounting them was just irrational behaviour on my behalf: I wanted to do something extra for my bike, that is, if it was not too costly and such a filter, mwah, doesn't cost much and maybe my bike would appreciate the gesture...

[slikwilli420]

FYI, I'm not the only one here that had nothing but trouble with inline fuel filters on a CB500 or 550. We can discuss all kinds of possibilities such as the minimal column height gravity has to exercise its force on these models, the limited space there is to fit one, often a cause for kinking, the filters position behind a pretty hot engine block, and so on, and so on... decades ago I gave up analyzing and just removed them. Never had any problems thereafter. As safety is a concern here, I feel it is my duty to warn CB500 and CB550 owners. Anything against that? If you have any doubt on my report, why not put it to the test on a CB500 or CB550 yourself? I have to warn you, make the test period weeks rather than days. Then we talk.

No intention of ever owning a 500/550 so testing isnt going to happen. Just interesting to see people vilify a simple inline filter to this extent.

[Deltarider]

Maybe you want to reread the #8 post (modified) above yours.

[Don R]

 My personal belief is modern fuels and moisture may cause a gel like coating to form in a small filter that gravity won't overcome. On my 76 super sport I wanted to drain the tank but couldn't get any fuel to flow out. I could blow air into the tank from the hose but still fuel wouldn't flow out, cap open, petcock on, tank full, on the center stand. I removed the filter and fuel flowed until the tank was empty. Just my experience.
 My Sandcast did it once on a ride, I blew into the gas tank, held pressure on it for as long as possible and then rode it on home. (glad no one got video of that). 
These days I use a little (1/2 oz.) of synthetic 2 stroke oil in my gas to protect my tank from rust.

[slikwilli420]

Dont see how filtering fuel before they enter the carb is irrational, so you lost me there. They are also easier to maintain than the one in the tank and can be replaced at regular intervals as well as inspected for debris. The issue of ethanol fuel is another one entirely and a bike ridden with some frequency will not encounter the phase separation issues often listed here. There are also a number of fuel additives that will combat that problem.

[flybox1]

Hi folks, I've got some light rust inside my '77 model CB550 tank. It's getting through to the (stock) carby's and occasionally the float bowls get stuck. I want to fix the cause and not keep treating the symptom.

What's the best way to deal with it?

I've heard a couple of different ways:
1. Use Metal Rescue (how do you apply it?)
2. Reseal the tank inner with some sort of Marine epoxy (seems the more expensive route)

What's best? What's worked for you? Advice and tips appreciated.

Jason.

Kleen Strip Prep-n-Etch.
$15  90 minutes.
Pour it in your empty tank.  Slosh it around every 10 minutes for an hour, resting on a different side. 
Drain it back into its container.
Rinse the tank out really with water from a hose.
Rinse that out with a pint of gas. (use this gas in an old mower)
Fill with fresh gas. 
Done.

[slikwilli420]

Hi folks, I've got some light rust inside my '77 model CB550 tank. It's getting through to the (stock) carby's and occasionally the float bowls get stuck. I want to fix the cause and not keep treating the symptom.

What's the best way to deal with it?

I've heard a couple of different ways:
1. Use Metal Rescue (how do you apply it?)
2. Reseal the tank inner with some sort of Marine epoxy (seems the more expensive route)

What's best? What's worked for you? Advice and tips appreciated.

Jason.

Kleen Strip Prep-n-Etch.
$15  90 minutes.
Pour it in your empty tank.  Slosh it around every 10 minutes for an hour, resting on a different side. 
Drain it back into its container.
Rinse the tank out really with water from a hose.
Rinse that out with a pint of gas. (use this gas in an old mower)
Fill with fresh gas. 
Done.

I would rinse the water out with a quart of acetone, since gas will not absorb water, you still risk having water left in your tank. Once acetone is gone, then fresh gas and go.

[Deltarider]

Or just fill up with ethanol gasoline. This may sound strange, but ethanol fuel is actually better to have in your tank hibernating, provided the tank is full. Separation doesn't happen that easily. Ethanol fuel actually binds moisture, where as conventional gasoline allows condens to build up in the form of water at the bottom of the tank. And these 'special' additives are mostly alcohols...

Dont see how filtering fuel before they enter the carb is irrational, so you lost me there.

Well, Slikwilly, what more can you possibly want to hear from me, after I have even confessed my stupidity back then adding not needed filters. Sorry, have to give up. Satisfied?

[PeWe]

The only thing I ever did, was throw a handful of balancer lead in the empty tank, then shake it for a couple of minutes and rinse the tank afterwards with diesel. I would start with that. Using the stock, now 42 year old, tankfilter I had no other problems than the occasional somewhat sticking float valve needle after hibernation. Extra inline fuelfilters however have proved to compromise fuel flow on multiple occasions.

I'll try that next time.
I got some light rust in a tank after cleaning it with water after paint stripper. Tank lid was on so I did not realize in time that water went in. i used a few liter vinegar I moved around for a few days to just make it much worse sine it culd rust more when not completely filled.
I filled tank completely with vinegar, let it sit for 4 days. Out with it, flush with water, garden hose. A few liter alcohol we use here for cars windscreens to remove water. Blew it dry with compressed air and finally 1 liter naphta + a few dl oil. Shake tank so it will be covered and out with the mix.

Shake tank with lead and diesel seems to be much, much easier. Our engines will be happy to finally get some lead again! 
Shot lead pellets or scuba pellets, right?
https://www.amazon.co.uk/LEISURE-PURSUITS-DIVING-WEIGHT-BALLAST/dp/B008GR50FY/ref=pd_sbs_21_5?_encoding=UTF8&pd_rd_i=B008GR50FY&pd_rd_r=c572633e-022e-11e9-9334-2994f224cbbe&pd_rd_w=6tHSG&pd_rd_wg=2uPMa&pf_rd_p=18edf98b-139a-41ee-bb40-d725dd59d1d3&pf_rd_r=EAJ1V8RTD4Y79S1KENJD&psc=1&refRID=EAJ1V8RTD4Y79S1KENJD

[Deltarider]

Pewe, the tyre workshop was glad I came to collect those balancer leads, but I'm sure you can find lead in another form more handy. Make sure to protect your hands when you deal with lead and/or diesel and after having had lead in your hands, wash them. BTW, it's not the same kind of lead that used to be in gasoline. There's some good info on that in Wikipedia. Scientists today look back at that era as the greatest mass poisoning ever in history.

[slikwilli420]

Or just fill up with ethanol gasoline. This may sound strange, but ethanol fuel is actually better to have in your tank hibernating, provided the tank is full. Separation doesn't happen that easily. So ethanol fuel actually binds moisture, where as conventional gasoline allows build up water at the bottom of the tank. Actually these 'special' additives are merely alcohols...

Dont see how filtering fuel before they enter the carb is irrational, so you lost me there.

Well, Silliwilly, what more can you possibly want to hear from me, after I have even confessed my stupidity back then adding an unnecessary filters. Sorry, have to give up. Satisfied?

Why count on ethanol fuel to bind the leftover moisture from rinsing the tank? Now you have invited the fuel to saturate with water. Better off to do it right. Like RIGHT RIGHT, not Deltarider right. Acetone is cheap, fuel tanks are not. Your choice.

Sticking with my unnecessary fuel filters until they cause an issue. Don't hold your breath, except you Delta, hold yours.

[Deltarider]

Slikwilly, you've said yourself you have no experience with inline fuel filters fitted on CB500/550 bikes and that you are not going to either. I do happen to have that experience and I feel I should share it. I hope you can live with that.

[flybox1]

I have rinsed with acetone before, and yes, it bind with the water to help it evap faster, but so does a little seafoam in your fuel.
Either way will work, but its best to get fuel in the tank as soon as possible.  I thought it best to save a step.

[ekpent]

 My tip would be to put a steel agitator in your tank like nuts and bolts etc. especially if your doing a tank that has a small lip inside like Suzuki and others. You can shake and shake to get stuff back out but sooner or later will be happy to get it out with a telescopic magnet    Quick rinse with toilet bowl cleaner on light rust followed by a heavy dose of baking soda rinse and a blow dry with my power vac in blower mode for a quick dry out and fuel right back in works for me and takes just a couple of hours. I block the filler hole with an expandable rubber plumbers plug and the petcock with a plate and piece of inner tube or a cork if its just one hole.   Eeezy peezy 

[Don R]

 I rinse with alcohol two or three times to remove the water and if I have it a shot of acetone last before adding 2 stroke gas and sloshing. 
  My brother used some wet gas in a 750 thinking the alcohol would cure it. The tank was junk by spring. Gasohol in a classic bike is only for when you're on the road and you need it to get where you're riding. My opinion only.
  Today I drained a full Goldwing tank with the bike on the lift and gas can on the floor. I was using the fuel hose off my IV bottle. The gas wouldn't flow until I removed the filter from the end of the line. I cant explain it but have seen it more than once. That said, some of my bikes still have filters because it's rare, I know what to do when it happens and I love my carburetors.

[Greaser Greg]

Skip the shaking, let chemical engineering do the work. There is a small risk of damaging the tank with too large or too much “agitator” dumped in and rattled about.

Pin holes near the badge mounts developed after I used nuts and bolts in a tank I cleaned.

[1977_cb550k]

Thanks everyone. I think I'll go with the Metal Rescue option, and will ponder what to rinse with. Probably acetone.

Interesting to hear how many different approaches there are to this common problem!

[Deltarider]

As a rule I always start with the easiest, often being the cheapest too. I'm with a growing number of people, that try to avoid products that need advertisements. Join the club and save an estimated average of 15-30% on expenditures! I should have clarified that ethanol gasoline is not the right choice to bind left water after flushing/rinsing. I thought that was obvious enough. It is a safe fuel for hibernating however, provided the tank is full. People that add products - much seen in advertisements (!) - to protect fuel from deteriorating, are in fact adding alcoholLOL. I also try to stay away as much as possible from agressive stuff like acetone. IMO a simple hairdryer with a hose attached*, is all what it takes to thoroughly dry out a tank. It's best done outside.
After you've cleaned your tank, I'd rely on the stock filter. I've heard of people that want inline fuel filters nonetheless because they're easier to clean. My stock filter never gets blocked, it's simply too big. It's also positioned thus that fuel sloshing around when riding, cleans it. Apart from the problems you may face on a CB500/550, I do not recommend forsaid inline filter cleaning practice unless you know how to avoid gasoline pouring over your skin. Your skin is a membrane. A membrane is a thing full of little holes. If your inline filter gets blocked, the problem lies elsewhere. Also the inline filters that I know are too small. The best have paper inside, but unfortunately those are too big for our bikes. Don't be alarmed by dust at the bottom of the floatbowls. It's quite normal to find some. It is harmless and will not make it to the jets. Not unless you start riding upside down. Let us know if you do and don't forget to post pics. Draining the floatbowls say every three months is more than enough.
* Hairdryers spark and you don't want that near gasoline vapours.