Circular water tank in spare wheel cavity

hehe..thanks Savvas :)

Yeah...after moving to the Jeep - it's a fair bit smaller than our GQ, so any better use of space is always a consideration. I was thinking of putting a diesel tank there, but I'll be putting that underneath along the LHS chassis rail (even though it's monocoque - it has some beefy rails still). So... water it is. Just a question now of how to plumb filler and outlet hoses through the walls of the cavity...

Thanks Andrew - Do you know the approximate dimensions of your 100L bladder?

Chrispy,

Apologies for the delay. I've been away.

I don't actually have my 100 litre bladder tank anymore because I sold it with my last boat. But from memory it was about 0.8m x 0.4 x0.2 (I think).

If you pop into a nearby chandlery, you'll be able to measure one no probs.

Andrew

Someone's been using a calculator!!!!!!

Thanks David

Yup - I get about the same figure doing the PiR squared by depth calculation too. There are a few protrusions (small hub in the centre of the cavity which houses the tie-down for the spare, but that's about it. I reckon around 65-80 litres would be sufficient. I want to go with a stainless tank taher than a bladder. Although the bladders do conform to irregular shapes, I'm just afraid of constant rubbing and chafing of a bladder tank while it's under the drawers - so it would never see the light of day for periodic inspection. At least with stainless - I'd be happy to leave it alone for years.

I'm definitely going to investigate further - and if no manufacturer has already thought of this idea, I'll whip up to Out of Town 4WD in the Newcastle area who manufacture from scratch. They're currently developing (this week!!) a long range tank for the Grand Cherokee CRD anyway - so this might be a good project for them too.

"you get 129.87 useable litres of space (pie x r² x h"

I am having some problems with this. The mensuration seems a little wrong.

Think of it this way............

60 - 70 litre petrol tank........... with a 127 litre recess...............

Wolfie

Well, I did the math, and you guys are right. Perhaps the fuel tank is like the Tardis!!

I just look at a 44 gallon drum, and think....... 200 litres........

I look at a wheel & tyre, and think........... maybe 40! I was wrong!!

I'm goin' back to school.......... with my slide rule!!

Wolfie

Actually - it's less.

31" wheel x 10" depth = 78cm diameter x 25.4 deep.

Radius = 1/2 dia, so we say 39cm radius.

Pi R squared = 3.141 x 1,521 (39 squared) = 4,777

multiply by depth (25.4) = 121,347 cm2 or 121 litres.

Given that there would be gaps down the sides and because of the hump in the middle of the well, lets losw 30 liters. We still wind up with 90 litres of usable volume.

Looks good to me ...... :)

(typo - cm3 not cm2)

Ray - don't inner tubes have a dust-coated interior? I think they dist it so that the inner walls don't stick together. It might be alright for washing water, but I'm not sure that I'd want to drink from it.

The shape would be right though! :)

ring some stainless steel manufactures & ask them but I don't think it will be cheap or easy to make as it's round. you could use a shure flow pump to suck it out if you can get it made. If you live in Sydney there is a stainless guy behind TJM @ Blacktown.