Topic: Rust Inside Gas Tank

[sniper1]

I have read through quite a few threads about rust inside the gas tank. I see a lot of mixed results with all of the methods (chemicals, electrolysis, etc.) Does anyone have a method that actually works? If so, what did you do? How did you do it?

I have a '75 CB550 tank that is in pretty good shape except for a quite a bit of rust inside. I don't want to have to buy another if I don't have to. Any assistance is greatly appreciated.

Thanks

[KingCustomCycles.com]

The works toilet bowl cleaner, 3 bottles in the tank with water fill to the neck.  Wait about 4 hours to overnight.  Drain and rinse with soapy water, add 1/4 gallon lacquer thinner and swish around, drain and dry with compressed air, immediately coat with gas tank sealer from NAPA.  Let dry 48 hours and you will never have a problem again.  Total cost: Under $20.00 and you will have sealer left for the next tank.  Done it dozens of times, works everytime, don't bother with fancy repackaged materials and bogus kits, waste of money.

[sniper1]

For $20, I will give it a try!

Thanks!

[Shaken]

Evaporust, 18 years in a garage 7 days later fit for fuel. was able to leave the petcock on and the gas cap 22$ a gallon i should of got 2 gallons 1 left a small area which i was able to reach with a small wire brush. This winter before I take my tank and side covers off to paint it will get the treatment again to remove the small area a clean tank is priceless. I am just lucky the guy shut of the petcock before he stored it. Though everything that can be adjusted had to be adjusted now this bike 1973 CB500 runs great and gets 44 mpg plus a little oil valve stem seals are next.

[cookindaddy]

I've learned not to sweat the rust in the tank but to make sure that the Honda in-tank filter on my CB750 K8 is in excellent condition and seated well with a fresh o-ring.  The 75 550K1 has a similar filter, Honda calls it a "screen set" in the parts fiche.

I have lots of rust in my tank which on the outside is beautiful.

The PO obviously did not know about the in-tank filter since he did some sort of treatment inside but left the filter in place. Needless to say it was glued in by the treatment and very difficult to remove. His "treatment" was peeling off the inside of the tank as well, rust underneath. What a mess. I cleaned it up and installed a new filter (still available from Honda).

Since I mounted this tank two years ago, I don't think that I ever have turned off the petcock. The carbs never overflow. The Honda in-tank filter keeps the crud in the tank.

I also keep the tank full of gas. The last thing on any ride is to top up the tank so there is as little air as possible in the tank. Keeps the tank from rusting further.

I am getting 55 mpg the last time I checked the beginning of this season.

[Tews19]

Evaporust! 20 bucks. Gallon at autozone.  You can reuse it as well. Did this a few weeks ago on both 75 and 78 550

[Nortstudio]

King, did you close the cap when you let The Works sit for 4 hours?

[ekpent]

Keep the cap open at first since there will be an immediate chemical reaction occuring between the Works and the rust. A gas will be given off which could cause excessive pressure.Let it rest for awhile or just flip the cap down but let it vent.

[Nortstudio]

Thanks. That's what I figured.

[Trav-i]

I had good success with the works as well.  Although my tank had some other serious issues which led me to cut it open and have it blasted on the inside.  Once it was back together I used Redkote (got it at O'reillys) for the liner and couldn't be happier.

[Nezhac]

I went down the POR 15 route,

from what I've read on this forum it's good for a long while,
however, on my tank (350F) you can't easily completely drain it from the petcock hole.
My newbie mistake was to empty the "metal prep" through the filler hole, I got a little on the tank and made some white etches in the paint.
Luckily for me, I rinsed it off right away and it eventually polished out.

just my 2 cents, watch out for your paint! 

[KingCustomCycles.com]

King, did you close the cap when you let The Works sit for 4 hours?

no, it builds heat and gasses with the chemical reaction of neutralizing the rust.  I clean the cap separately.