Sill Tanks for the Cheapskate

[alexturner]

Hey Guys,

Just another stupid question....

I've been wanting to put sill tanks in my Defender for a while now though I can't afford anything in the realm of prefab. I was going to build my own units from steel and was going to ask if anyone has any plans or designs before I get under the car with cardboard. Any tips and tricks? I was going to bend as much as possible and keep welds down to a minimum. I was going to strap them in and was planning on using galv steel. I'll have them pressure tested at a radiator shop.

Thoughts feelings opinions?
Thanks guys

[steveG]

Don't waste your money pressure testing them at a radiator shop - its easy enough to do yourself with an air supply, a pressure regulator and some soapy water.
Put abut 3-4 psi in the tank, and run around all the joints with soapy water and a brush. Any leaks will bubble and be easy to see.

Not saying the radiator shop wont do a good job, but if you do find a leak that you need to fix, you could be back there a couple of times to get it re-tested - so time/money.

Steve

[dromader driver]

In the back of my head there is a restriction on using gal steel with dieso. Can't remember why though. Would be interested in your final design.

Drom :(

[KarlB]

In the back of my head there is a restriction on using gal steel with dieso. Can't remember why though. Would be interested in your final design.

Drom :(

Yes, the zinc reacts with the diesel causing it to break down. The 'reaction' zinc compounds, including 'gum', then play havoc with the rest of the fuel system, probably affect the cylinders, and contaminate catalytic converters. See The Effects of Zinc in Diesel Fuel Systems | eHow.co.uk (http://www.ehow.co.uk/list_6758941_effects-zinc-diesel-fuel-systems.html) for starters, but a Google search will find far more info. Stainless steel is the best way to go, and this may be why some aux tanks are expensive (but probably much cheaper in the long run).

Cheers
KarlB
:)

[Nera Donna]

Had a 150 ltr home made steel diesel tank in a 4wd I had a while ago now. It was there when I bought it. Very big pain in the backside. Tank had started to rust on the inside, when you hit the rough stuff the rust would come loose and block the fuel line. Had the tank out three times, cleaned it, repaired it and put it back in. Still after about a year the problem would resurface.
My suggestion is to consider ‘lining’ the tank with something. What I don’t know, to avoid this scenario happening to you.

[steveG]

A search on here should turn up some recommendations for tank sealants that you can pour into the tank to seal/coat it. 3M and POR are a two manufacturers that come to mind.
3M coatings are used extensively in aircraft fuel tanks, but POR also have a good reputation.

Steve