Inside a VF tank

Opened this up to do some work and here is what I found!!

the photo seem to clean it up a little, the whole of the inside looks to have about 1 millimetre overall of the treacle/honey residue, its very sticky, I have cleaned about a dozen tanks this year and the residue has a tendency to stay at the lowest point of the tank, this one is my own VF tank which I am modifying, which is why I have cut the hole. Phil.

Hi Phil,

What do you clean the tanks with? I’ve been looking at mine and wondering the best way to go about it.

Also any chance of a photo of the inside above the tap, I’ve been trying to see what’s in there but can’t get a look.


On this tank mostly I will clean with cellulose thinners and scotchbrite pad, scrubbing manually, to remove the Goo, then submerge it in hydrochloric acid to remove any rust, followed by caustic soda, this is ok on tanks that are to be painted, for tanks where the paintwork is good, I fill with glass grit or shot (as used in industrial blasting) mixed with Kerosene and thinners, I then strap it to a machine I have built which rotates the tank at 40 RPM with the grit gently scrubbing the inside, I leave this running for around 10 hours, followed by washing through with clean kerosene. I have not used the process with grit on tanks such as the VF yet because of the fixed internal mesh filter, I wouldnt like to think any grit would be caught up in the mesh.
Here is a photo of the internal pipework:

I also have my own VF tank to check because this has got me wondering what is inside that one, I might just try rotating with kerosene on its own to see what happens.
If you want to clean yours by rotating, see if you can access to a cement mixer, I originally made a frame that clamped onto the front of the drum for the tanks to sit on, then used ratchet straps to tie it down, don’t be tempted to put the tank inside, even if you pack it with something soft, It will work loose with dire consequences[xx(]

That’s what I have been trying to get a look at, I wonder who thought of fitting an internal mesh screen that can’t be accessed without cutting the top off the tank!

I have some light surface rust in the tank and have heard of using dilute hydrochloric acid to remove it, might try the kero to remove the gunk first as you suggest.

Thanks again for the picture.[:D]

I have dipped a piece into caustic soda and it seems to be shifting it. I will leave it longer to see what happens, I have also dropped a tank into the caustic soda just to see what happens to the paint, it has cellulose on it which is quite soft compared to 2pack, I forgot to mention that the brown goo is some sort of enzyme or similar sort of stuff which multiplies once a tank is infected, it feeds on hydrocarbons in fuel[:(!]

Kinell philjo…you know ya stuff…I AM impressed…

Sooo…some advice please…

Got my original tank…and was about to chuck it out!

original owner pre 1991 had a major off personal injury-wise…not much bike damage other than a bloody great dint on the front LHS of the tank…which he suitably filled with…yes, filler…and a very bad touch up with a soft yard brush and some black and grey hammerite ! ( well, that’s what it may as well have been done with) [:D]…Over the years the paint has deteriorated and the filler lump has decided to leave the tank…hence my giving up with it and getting a very nice red/blue/white tank from the States.
It has since languished in the corner of the garage…taking up room.

As you seem to be a Master at this art…how ya fixed for me fetching it over for you to give me a prognosis on it?

(Well, I have been threatening to come over haven’t I!)

Phil have you ever tried using electrolysis (bath of washing soda and battery charger setup) to remove rust from tanks?
My dear old dad has been using this sort of setup for quite a few years to clean up rusty parts with great success.
I was thinking of setting up a big plastic tub of it and dropping the whole tank in.

Hi, no I hav’nt tried electrolysis yet, though I had thought about it, I have a variable power supply unit which I could use 0-20 volts, caustic soda removed the brown goo nicely, there was an article in classic bike mag a couple of months ago about electrolysis, I will find them out.
Hi, tim dont chuck out that tank! yes I can take a look, anytime, I’m not spending as much time working away from home lately so its given me more time to catch up on a thousand jobs plus making a move on the VF, just let me know when and I’ll get the kettle on, Phil.

Just a thought before I use tank sealer! has anybody sealed a tank then had problems with fuel flow because of the fixed mesh filter inside? I dont want to seal the mesh for obvious reasons.

This problem is multiplying. It is now occuring in old cars as well and appears to be caiused or exacerbated by Lead free fuel!

I dont know about you guys in Britain, but here in Australia we are being sold fuel that is lower in quality every year. Now we are being sold fuel from India, Hmmmm I bet that is great quality!
I have been told about this problem in cars here for a decade of more and it is becoming more and more frequent, one workshop told of strange growths not unlike tentacles in one case and another workshop said it was like coral growing inside the tank!
Just to qualify these statements, I have not personally seen these incidents but I have personally had one car that started blowing white smoke immediately after filling up, and my daughters car just lost power until it would no longer run, both times the problem was rectified with fresh fuel.
I cannot help but think that the oil companies are trying to find cheaper ways to produce fuel (while charging more) and are not concerned about the effects on our machinery.