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DIY ali petrol tank
02GF74 - 15/3/06 at 04:41 PM

I am toying with making a lighter petrol tank (one I have is in stainless) out of aluminium.

My MIG welder supposedly welds aluminium - has anyone made a non-proprous tank using a MIG? Just wondering if it is even worth having a go. (will play with some scrap sheet).

what would be a good thickness, 1 mm too thin? (I realise thin ali is hard to weld so maybe 1.5 or 2 mm?)

[Edited on 15/3/06 by 02GF74]


hector - 15/3/06 at 04:47 PM

I just had an ally one fabricated from 1.6mm ally, put one baffle in it with the bottom corners cut off and a couple of 50mm holes evenly spaced in center.

It was TIG welded, and it is VERY strong bearing in mind its dims are 800mm x 220mm x 350mm high

cheers Colin


Fred W B - 15/3/06 at 06:10 PM

I'm probably going to regret this, but ......

I can't get used to the idea of carrying fuel in a tank that is so thin in stainless, let alone in ally.

Have any of you seen that famous picture of Matt ?? (old CCC test driver) in a seven that has just been hit from behind, with a huge fireball reaching for the sky?

My background is in designing and building (admittedly bulk) tanks for international transport of hazerdous liquids, of which petrol (due to flashpoint) is one.

For international (bulk) transport, the minimum material by law is 4.2 / 4.5 mm stainless.

For my fuel tank, the choice will be between 3.0 mm ally, or 2.0/1.6 mm stainless

Cheers

Fred WB

[Edited on 15/3/06 by Fred W B]


Dale - 15/3/06 at 08:38 PM

I am going with 1.6 mm stainless- just because i have a couple of sheets of it in the garage.
Dale


britishtrident - 15/3/06 at 08:58 PM

Then you put fuel in it -- any weight saving almost insignificant.


JoelP - 15/3/06 at 09:01 PM

my plan, from a weight saving point of view, is to use a smaller tank, approximately 10 litres, and circular like a swirl pot, as this will reduce the amount of material (smaller surface area etc). I will then place it at the passengers feet, as it will be more protected and nearer the engine.


DIY Si - 15/3/06 at 09:18 PM

Just take passengers you don't like out and you'll be fine! Or are you putting it in a structural box/behind a fire wall?


mark chandler - 15/3/06 at 09:53 PM

But back to the post, mig welding ali is bloody hard, nigh on impossible for a leak free tank on home tools.

Secret with ali is cleanliness, you will also need argon, new liner & tips (as any fragments of steel will kill the weld).

I,m afraid TIG or gas is the way to go or expect a blacken molten mess... been their !

Regards Mark


nitram38 - 15/3/06 at 09:59 PM

quote:
Originally posted by Fred W B
I'm probably going to regret this, but ......

I can't get used to the idea of carrying fuel in a tank that is so thin in stainless, let alone in ally.

Have any of you seen that famous picture of Matt ?? (old CCC test driver) in a seven that has just been hit from behind, with a huge fireball reaching for the sky?

My background is in designing and building (admittedly bulk) tanks for international transport of hazerdous liquids, of which petrol (due to flashpoint) is one.

For international (bulk) transport, the minimum material by law is 4.2 / 4.5 mm stainless.

For my fuel tank, the choice will be between 3.0 mm ally, or 2.0/1.6 mm stainless

Cheers

Fred WB

[Edited on 15/3/06 by Fred W B]


Your tanks are bound to be that thick. 1 litre of fuel weighs 1 kilo (approx) so your tanks need to be thick for the weight. Plus most lorry tanks are exposed to the possibility of a crash without protection.
Most motorsport tanks are 1-2mm Aluminium. If you are worried, fill the tank with fuel foam. It is vapour that ignites and not the liquid. The foam will reduce the vapour space.


tomblyth - 15/3/06 at 10:06 PM

Alloy is fine but if I were you I'd draw what you want and send it to Deneo (do search on here)
and work on the bits that Migs are good at!


cita2 - 16/3/06 at 04:04 AM

If it's a simple structure why not glue and rivet the ali tank?
To make it liquid prove the tank is sloshed with a fuel prove sealant.
It has been done for aircraft fuel tanks ( not the ultra light stuff but if I recall correctly,the P-51 Mustang had such fuel tanks.)
It certainly will be easier to fabricate and probably cheaper as well.
Baffles can be installed much easier to stiffen the structure.

Cheers Cita


NS Dev - 16/3/06 at 08:31 AM

quote:
Originally posted by Fred W B
I'm probably going to regret this, but ......

I can't get used to the idea of carrying fuel in a tank that is so thin in stainless, let alone in ally.

Have any of you seen that famous picture of Matt ?? (old CCC test driver) in a seven that has just been hit from behind, with a huge fireball reaching for the sky?

My background is in designing and building (admittedly bulk) tanks for international transport of hazerdous liquids, of which petrol (due to flashpoint) is one.

For international (bulk) transport, the minimum material by law is 4.2 / 4.5 mm stainless.

For my fuel tank, the choice will be between 3.0 mm ally, or 2.0/1.6 mm stainless

Cheers

Fred WB

[Edited on 15/3/06 by Fred W B]


Yeah, I remember that photo!!! Nice and warm in there I would say!!!

That was the Kiwi fella wasn't it, what was his name?


02GF74 - 16/3/06 at 12:38 PM

quote:
Originally posted by britishtrident
Then you put fuel in it -- any weight saving almost insignificant.


the weight saving is the same regardless of whether it is full or not. ofcourse the overall wieght depends on how full the tank is.

I am still tempted to give it as shot but as I expect, it won't be easy.