Petrol tank electrolysis

[BooG]

Having some wonderful results cleaning the tank with electrolysis. What is all the gunk that comes out....is that all rust!!??

[Bob_Roller]

There was a red liner applied to the inside of the tank at the factory .

When I relined the interior of the fuel tank on the '84 LS, I was surprised how much rust came out of the fuel tank, using strong ( 10 % acid ) vinegar to dissolve the rust .

My '87 Guzzi had more rust come out of it than the LS did, no liner in that tank .

Are you going to use apply a liner when you get the rust out, or just leave the metal bare

[Luca]

Only problem with electrolysis is it's a line of sight process.  My tank looks pretty good when I peep through the fill opening.  When I take a borescope (camera on a flexible stick) and really look into the tank, things get a lot crustier; specially on the RH side, which is hard to see.

[BooG]

I think I'll leave it as God intended; no liner. I'll put another filter in the fuel line and see how she goes. Tank looks pretty clear, and the metal shows up nice. Sprayed a load of WD40 into it after drying out to prevent rust forming before I get the chance to fill up with petrol. Also, I dropped the anode into the tank, so I'll have to extract that before continuing...always something extra, eh!!?

[georgesgiralt]

Hello
If your fuel contains ethanol, it de facto contains water and will attract the air water above it.
So IMHO, it is not a good idea to leave the tank un-coated...

[Barry]

My liner is still good but if it wasn't I think I might be tempted to go with bare steel. Are tanks in all modern vehicles coated ?   A small dose of two stoke oil might help keep corrosion at bay.

[peteremc]

I'm just about to put a liner into a "less than ideal condition" tank I'm using on an R65 resto. I really like the idea of the lining for a number of reasons, not least that it is a physical barrier, and I'm willing to spend the money for the peace of mind - rather than gamble and sweat about it.

Barry, wouldn't a layer of 2 stroke oil just mix with your fuel over a very short period of time and just create some interesting smoke that is usually not produced by a (well maintained) 4 stroke?

[Barry]

I was thinking of the very low dosage rates used for an upper cylinder lubricant in 4 strokes. A ratio of 1:640 doesn't produce any smoke. The only visible effects at that dosage is a very slight colouration of the plug insulator.  

[Luca]

Barry, my experience as a small engine mechanic is that two stroke fuel system components are just as susceptible to corrosion.  In fact, it's a bit of a problem with echo/shindaiwa carburetors at the moment.  They are going to start using an improved plating to help stop the corrosion.  It doesn't help that alcohol does a number on aluminum to begin with.

I think the reason two stroke stuff seems to fare better is that most of it is not openly atmospherically vented and a lot of two stroke oils contain stabilizer.  The ethanol in two cycle mix still absorbs water and can separate if saturated.  While the oil will add a bit of lubrication to the top end, it won't keep water from sinking to the bottom of the tank.

[Barry]

I still wonder how unlined steel car fuel tanks get by. Possibly many new tanks are now plastic.  Perhaps car tanks get less condensation because they are more effectively sealed from the atmosphere. We must all have noticed the in rush of air when the fuel cap is removed. I recently looked at a friends steel tank taken out of a 20 year old car.  It was leaking but it had rusted from the outside not the inside.

I guess we would all be better off without the ethanol. Maybe if the UK votes to leave the EU ethanol will stick at 5% instead of increasing to 10%.  It would get my vote not because it's a big deal but because it's symptomatic of the decisions that the bureaucratic EU produces and will continue to produce.

[Bob_Roller]

Get the ethyl alcohol out of the fuel supply and back into the whiskey, where it belongs !!!!

[clonmore1]

Good to see Bob gets the thread back to the real issue!