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[matap]

My own personal experience on how to remove rust from the inards of a gas tank. 

First off I have a 2003 shadow that I recently re-acquired from an old friend that pretty much neglected and left the bike outside for about 2 years with no cover or anything.  Needless to say it now needs copius amounts of work. 

Supplies needed:

Distilled Vinegar - amount depends on size of tank(gallons)
Nuts & bolts - about 1-2 cups worth
WD-40
Masking taping to seal holes in tank


Aside from the carbs needing a good rebuild & cleaning, the tank had to be first on the list b/c what's the point of doing carbs and having a dirty tank.   

Step 1:  Remove and drain tank (this won't be bike specific as this is just how I removed the rust) completely then let it air dry.

Step 2:  Take about 1-2 cups of random nuts and bolts. preferely with large washers attached to them.  This will aid in removing the heavy rust flakes. Tape/seal any openings on the tank.  You will want to shake those nuts and bolts inside that tank for about 30 minutes to an hour.  The method I chose was to place in the dryer.  Yep you read right....the dryer.  Wrap in a blanket place inside dryer then wad more blankets or towels until it is completely wadded through so there is zero movement.  Run that dryer on spin cycle with no heat for about 30 minutes. Take it out and reverse it's position and run for another 30 minutes. 

Step 3:  Remove all the nuts and bolts.  One of those nut grabbers  works great.

Step 4:  At this point it's probably real dusty with rust.  This needs to be washed out.  Take your garden hose and jam it down the fill hole.  Shake, rinse, drain, repeat until the water mostly comes out clean. 

Step 5:  Now most of the hard stuff is out, but if you know rust it's a chemical reaction of H2O reacting with metal so to fight fire with fire you need another chemical reaction that eats rust in the real tight places.....Acid.  Use, depending on gallon size of tank and fill it with Distilled Vinegar or Distilled Apple Cider Vinegar.  Both work great, but Apple cider vinegar is about 1% more acidic in most cases.  I let the vinegar sit inside the tank for about 5-6 days.  No heavy agitation is necessary, but I did shake it around once in the a.m. and once in the p.m..  Be sure to seal any holes that would cause draining.  Make sure it seals tight and be sure that you fill the tank to the absolute top or you will rust badly at the liquid line in the tank. 

Step 6:  Once you've let it sit for the whole week you are now ready to drain.  But before you completely drain the Vinegar, you'll need to nuetralize the acidity.  Pour all but about 1/4 of the vinegar out, then dump about 1/2 cup of baking soda.  You'll remember from your science classes what happens when vinegar and baking soda come into contact, yep, it fizzes up, plus it also helps in breaking that last bit of rust.  Drain that and start pouring water from hose and fill it up, shake, drain & repeat until it comes out clean.  This make take some time depending on how bad the tank is. 

Step 7:  Remove water.  Drain as much water as possible.  I also used a shop towel to absorb it up a bit.  Before it starts to flash rust pour some gasoline inside the tank and swoosh around attempting to coat the entire inside.  Drain it then do it again and drain it again.  Now that should help in removing all the water from the tank. 

Step 8:  preventing flash rust.  Now that your tank is all clean, keep it from flash rusting so you don't have to go thru this nightmare again.  Take a spray bottle of WD-40 and spray it in the tank.  The secret to spraying is to not spray like you are trying to coat a rusted bolt for removal.  You want to fog the tank.  Best way I've known to do that is spray holding the can horizontal to 45 degrees upside down.  This causes it to sputter.  Do that until you see it fogged.  Close it and leave it alone until ready to use. To clean that WD-40 out when you are ready to use just pour a little bit of gas and swoosh it around and drain it.  Tank is ready to use.   

Hope this helps someone trying to clean that rust tank project. 

works great and the only cost associated is buying the vinegar, nuts & bolts if you don't have them already, and tape, again if you don't have already. 

[hooter]

 

[Gumbo]

Dang good write up

[Drewboy22]

Great write up!  Who woulda thought, a dryer?  Clever... 

[Tapper]

I don't recommend the nuts/bolts/bb's method, just because it an be a real pain to get them back out of honda gas tanks.  I use a different method:

Start with a tank with everything off/out of it.  Strainers, fuel pumps, whatever.  Nothing but tank metal left.  Buy a couple of rubber caps to plug off the vent line, and maybe a big cork for the fuel cap hole.

Go buy a gallon jug of muriatic acid from the pool store, and a bottle of naval jelly (maybe 8 oz or so).

Shake hell out of the tank upside down to get out as much grit and loose junk as possible out of the gas cap.  Expect a workout on a honda tank.

Now, in a plastic bucket, pour naval jelly and a gallon of water in and mix.get it nice and smooth.

Do whatever you gotta to prevent any muriatic acid (HCL) from getting on the paint in this next step.  I use a paper funnel and a measuring cup.

Plug tank up, and fill about 2/3's with water from hose.  Slowly add 4-5 cups of muriatic acid.  SLOWLY.  DO NOT PUT ACID IN TANK FIRST.  WATER FIRST.

Plug up gas cap, then slosh mixture around inside tank for a couple of minutes.  Repeat every five minutes for about half an hour.

Turn on a garden hose, and find a good place to dump the tank.  the mix isn't all that dangerous, but it will discolor concrete.  flood the outside of the tank, remove cap, and dump tank while flooding paint area and anything acid might touch with lots of water.  Aim the hose at the mix you dumped out and dilute the hell out of it.  acid dilutes very fast and well.

Now, before inside of tank can dry, pour the naval jelly mixture into tank.  Slosh it around and rotate tank in all directions to be sure inside is completely coated with the mix. Do this 4 or 5 times, then dump out the mix in the same manner as before, with a hose and tons of water. 

Set the tank upright and let dry 20 minutes.  Flip the tank, let dry 20 minutes.  Then, rinse insides with water.

Remove all plugs, and let tank dry in a nice warm place ( I always set tank in sun) for several days.  Tank needs to be bone dry before you put gas back in it.

Thats the process.  The muriatic (hydrochloric) acid will dissolve the rust and any remaining varnish/old fuel right out of the tank, and usually leaves it nice and clean.  Naval jelly is basically phosphoric acid.  It will leave a long-lasting phosphate coating inside the tank that prevents the flash rusting that WILL happen after you clean one out.

Works for me.  Good luck!

[hooter]

Thanks for the chime in and a great write up! Hope your doing ok, hadn't heard from you in a while. Take care and hope your back (I believe I had heard you were having problems) is better.
 

[MRVTX]

Talk about TBT!     Good to see you're still alive and kickin', Tapper!   

[xcaliber]

  Good to hear from you, I enjoy your tech write ups

[hipshot]

I've seen gravel and water used on a boat's fuel tanks.  Worked well.

[Tapper]

I'm actually back riding again now.  For a while there, when I blew out my back, things didn't look too good.  I had a surgery that didn't work, and a lot of nonstop pain, and the painkillers to go with it.  Got to where I could barely walk with a cane, and between the pain and the codeine, I just lost all interest in doing much of anything, with anybody, and disappeared for a while.

But things got better, the pain subsided, I quit the painkillers, and slowly reclaimed my life, albeit with continuing back troubles.  But then I went and actually did something smart - I went on a serious diet, lost all the lard, and started working out - easy at first, but increasing gradually over time.  Now, 3 years later, I feel great.  No pain, can pretty much do what I want to do. 

I sold my VTX last year, and bought one of the new Rushmore Road Kings (great bike), and ride every chance I get.  Mostly alone, but I'm starting to ride with other folks a little.  I do miss riding with the x-riders, and wonder what happened to all the people I met there.  I have good memories.

I don't spend as much time online anymore, too much to do elsewhere, but I do check in from time to time.  Don't be surprised if yall have a ride, and a goofy guy on a black roadie pulls up.

[MRVTX]

Glad to hear you're doing much better.  Those RGs sure are nice.

[mitchntx]

Went through this with my newly aquired X. After the ground fix, valve adjustment and plug change, I was installing the tank.
I pulled the plug for the primary fuel line and good gosh, the fuel was nasty.
So I stopped and began reading up on what to do.

I was leery of pooring some sort of aggregate into the tank for fear of never getting it all out.
There is a splash collar (that doesn't completely work) sticking into the tank about an inch that would capture some of the aggregate.
I didn't have a replacement gasket to remove the electronics panel from the tank, so I crossed those methods off of plan A.

I did find an interesting, soft bristle brush in Home Depot used in cleaning dryer vent ductwork.
Handle was long, flexible and tapered to a point. Used it during a Dawn/water cleaning ... a lot of "chunkage" came out.

3 gallons of acetone and one gallon of MEK later, the tank dried overnight and went back on the bike the next morning.
Next time I pull the tank I'll pay close attention to how the fuel looks.

Plan B will be acid etching and coating. I'll have all the parts needed to R&R all the tank components before I start.

[bluestreak]

Using Phosphoric acid works great.
Get it from Home Depot.  Behr Paint Company makes a concrete cleaner product which is actually about 75% phosphoric acid if I remember correctly.  One gallon diluted to 2-3 gallons of water works fine.  Initially flush tank with water then fill the tank completely with the diluted solution and let it sit for a few hours based on how bad the tank is rusted.  I also agitate the fluid by introducing compressed air into the fluid through a long brass tube (18” long) connected to hand held air nozzle.  10-15 psi air stream agitates the fluid enough and serves as a scrubbing action to loosen heavy rust.  When the acid has done its work, flush with water well, rinse with a solution of baking soda to neutralize any remaining acid, then rinse with a pint of denatured alcohol, then air dry with a hair dryer.  When dry it will look brand new inside. Immediately spray with WD-40 or fill with gas to prevent any surface rusting.

Fuel with ethanol is terrible.  It will turn to crap in just a few months if there is any air space in the tank and the bike is left to sit in storage.  The key to keep the gas from turning bad so fast is to make sure the take is completely full of fuel before the bike is allowed to sit unused. Any air space above the fuel surface contains water vapor which will be absorbed by the ethanol which accelerates the fuel degradation.  An ethanol specific fuel additive will also help to keep the alcohol in solution longer.

[xcaliber]

What's up Mike, what you been up too?

[Gumbo]

Hey Mike