Cleaning MC fuel tank of rust & debris

[Caprimaniac]

Awrighty, then....

2 years later, and have been running for a season or two since rinsing inside of tank in HCl and kerosene etc. Carbs worked out fine after a couple of rounds of cleaning. 12 full tanks later, there are still trouble.

Used the old fuel- tap gaskets and had some minor leaks of fuel. Sometimes not minor, ruining some sq feet of asphalt....

Got a New set of gaskets for the fuel tap, assembled and got a small set- back and then everything seemed very well... In a couple of days.

Opened the tap today and find a layer of brownish dust-like matter covering the inside of the tap.... So: I need to seal the rust.... I think the only solution here is molasses... and then some Paint/ epoxy.... I will search the shops around here to see if anyone have the Products mentioned.

Any kind of advice on "Paint" is taken serious here...

In my opinion; the 5% ethanol gas we have over here, wouldnt it eat most of the water? I mean- all the water- removing agents you put in the tank is ethanol- based (which disssolves the water, which then is carried into the fuel and burned).
Or is it the other way around: Does it leave some kind of residue or even make the tank rust?

[pamotorman]

http://www.evapo-rust.com/

[modok]

i once encountered a very rusty and dirty tank, from a toyota truck that sat for a decade.
At first I tried the usual rinse with solvent then muratic acid, but it didn't work. I used a long screwdriver and scraped a "chunk" of rust/goop off the bottom......then tried dissolving my sample in this and that. Acetone seemed to work well. I put a gallon of acetone in the tank and let it sit for a day, shook a few times, when I poured it out I had one gallon of brown acetone and a 1/4 gallon of rust flakes. Then did the acid again and it was clean as new.

I am very impressed with the acetone. In order for the tank coatings to work, they say the preparation is KEY, and now I know the key to making THAT work is clean with acetone, to dissolve any GUNK.

[oldjohnno]

I've had good results with Caswell tank sealer, a phenol novolac epoxy. It resists alcohols well and I use it with fiberglass tanks to prevent them from being damaged by the ethanol in pump fuel. It's tough too - one plastic tank I lined was crashed hard enough to put a long crack down the top yet the lining remained intact and doesn't leak.

[Caprimaniac]

Will try to find the suggested products over here . Couldnt find Kreem, some more to chelck. Thanks fornsuggestions.
Found Tank Cure.... Will start with hydro hloric acid, then water, and gereous washing with acetone efore the epoxy.

Some mention of phosphate... phosphorous acid, H3PO4..... is that something that can be used? Will it react to to form a un-dissolveable layer?

Use anninspection- camera to locate the excact spot, and leave the "paint" where it's neede only?
Hell, a small camera like that is great to inspect cylinders and piston tops too.I should get one.

[jacksoni]

http://masterseriesct.com/home.php

[ijames]

Will start with hydro hloric acid, then water, and gereous washing with acetone efore the epoxy.

Hell, a small camera like that is great to inspect cylinders and piston tops too.I should get one.

Any gasoline or oil or grease or gunk film will protect the rust from acid or other removers like evaporust, so start with soap and water to get the worst out cheaply, rinse well and let dry, then a couple of washes with acetone (it sucks up water which hurts the gunk-dissolving power so dry the tank first), let dry, and only then go on to the acid or evaporust. Haven't had to clean a gas tank but I'm a fan of evaporust, used up a few gallons so far on various small items. It's a bit pricey but you reuse it over and over and over so per item it's pretty cheap.

I needed a toy so got one of these a few months ago: https://www.amazon.com/gp/product/B01FU ... UTF8&psc=1. It's a very thin 7 mm dia USB video borescope that you can watch on a smartphone (check the ad to make sure your phone will work), tablet, laptop, or any pc, with a 5 meter (15 foot, they have other lengths) cable, for just $10 USD. All the reviews say their software has viruses so I didn't use it, but on my win7 tablet I just plugged it in and the same software that controls the built in cam found it just fine. There are free generic phone apps that work too, so read the reviews to see where to get one of those (I haven't yet, once the tablet worked that was enough for me to play ). Best focus is 2-4 inches, picture quality is ok, LED's a bit weak but well worth the price.

[GARY C]

I would use vinegar and a piece of small chain to prevent dings.
https://www.youtube.com/watch?v=TlcL_vHODkc

[vwchuck]

The only shit that works is US standard gas tank sealer. Look on amazon. It is methanol, ethanol, race gas, everything proof. It stays flexible and never comes off. Other ones I have used chip right off even when you follow all the directions.
I use some muriatic acid in the tank with water. That will etch it real good. Make sure it is dry and dump in the sealer and rotate the tank around to coat. Then dump the excess back into the container. You never waste any as it can be reused. Good stuff.

[66Vette]

Here's is what I did on a 1970 Honda CL350 gas tank that had moderately heavy rust and had been sitting for some time.

1) Pull the petcock and plug opening.

2) Select pea gravel size from 1/4" to 1/2" and wash thoroughly.

3) Put a cup or two of the pea gravel in the gas tank and fill tank approximately 1/4 full with diesel. The diesel works as a solvent, lubricant, and moisture barrier.

4) Shake the tank until your arms fall off. You will be surprised at how clean the tank will be after this step. It not only knocks off loose rust, but polishes off most of the surface rust.

5) Empty pea gravel and diesel. Then rinse in hot water and Simple Green.

6) Dry gas tank (do not let sit around too long or surface rust will reform). Fill tank 1/3 with Evapo Rust, rotating the tank every day or so to let the Evapo Rust work in different parts of the tank.

7) Rinse tank out with hot water and Simple Green, spray heavily with WD40 to pick up any residual moisture.

Fill with gas and you are ready to go. I was reluctant to use any sealer and have not had any issues with my un-coated tank.

[My427stang]

That Evaporust is magical on parts in a bucket, water based, non flammable. I'd fill that tank and walk away for 24 hrs, then rinse out with alcohol. I bet you'll be amazed

[Caprimaniac]

Will start with hydro hloric acid, then water, and gereous washing with acetone efore the epoxy.

Hell, a small camera like that is great to inspect cylinders and piston tops too.I should get one.

Any gasoline or oil or grease or gunk film will protect the rust from acid or other removers like evaporust, so start with soap and water to get the worst out cheaply, rinse well and let dry, then a couple of washes with acetone (it sucks up water which hurts the gunk-dissolving power so dry the tank first), let dry, and only then go on to the acid or evaporust. Haven't had to clean a gas tank but I'm a fan of evaporust, used up a few gallons so far on various small items. It's a bit pricey but you reuse it over and over and over so per item it's pretty cheap.

I needed a toy so got one of these a few months ago: https://www.amazon.com/gp/product/B01FU ... UTF8&psc=1. It's a very thin 7 mm dia USB video borescope that you can watch on a smartphone (check the ad to make sure your phone will work), tablet, laptop, or any pc, with a 5 meter (15 foot, they have other lengths) cable, for just $10 USD. All the reviews say their software has viruses so I didn't use it, but on my win7 tablet I just plugged it in and the same software that controls the built in cam found it just fine. There are free generic phone apps that work too, so read the reviews to see where to get one of those (I haven't yet, once the tablet worked that was enough for me to play ). Best focus is 2-4 inches, picture quality is ok, LED's a bit weak but well worth the price.

That's a great camera- soution right there. It didn't say anything on Apple- Phones???

I bougth a cheap USB- port camera, although 10mm, but oK resolution/ colours and use my Laptop for this stuff.

Afterthought; yes- see Your point on cleaning With watere detergent before going to the Heavy stuff to make the rust more available to the acids. Thanks for Your Insight.

RS

[Caprimaniac]

Let me just drop a line how Things went by.

First off all; bike broke Down by some electrical faults last year. Got the bike home to my old man's garage. While sitting there the engine got flooded once more, and I removed the tank.

Used warm water, detergent and gravel. Washed well, rinsed With hot water. Then removed debris & gravel; not easy. Using a vacum cleaner With 1/2 tubing.
Then a good 20 min or so With HCl.
Then acetone for a good rinse.
At last some 2k epoxy tank sealer.

Mounted the tank, fixed the petcock With New gaskets. All well for now.

However, there are some Electric goblins around, and after much work; testing diodes and relays. Haven't found anything wrong. Only 9V to the starter relay, not enough to engage the relay. Headlights not working. If anyone knows where the culprit is...... Give me a hint....


Lesson learned: DO NOT USE GRAVEL in tank cleaning; it's a hell of a job to get it all out Use steel bolts, nuts, etc and remove With a magnet....!