Fuel Tank Stainless or Alum 3

[Christo_AU]

Hi All. We have to fabricate a 200 litre (50 gallon) fuel tank that will be underslung a trailer. This fuel is not for the truck, it is for a generator mounted on the trailer. Someone told me that it is better to fabricate it from alum sheet, because they said stainless steel sheet will crack. Can someone please validate this and explain why stainless steel sheet will crack but not aluminium sheet when used for a tank on a trailer?

 

[EdStainless]

The SS will be stronger and much stiffer than Al.
But do you need those properties in a tank?
SS is easier to weld than Al in my book (I can't weld Al for crap).
It wouldn't surprise me if you couldn't fins SS tanks that were deep drawn and then the two halves welded together.
SS forms easily (think kitchen sinks).

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P.E. Metallurgy, consulting work welcomed

 

[georgeverghese]

Talk to these folks:

https://www.tti.com.au/product-cate...O-ftGLtnVg66G3voUM3Qi5RVSxtMKY5oaAmRtEALw_wcB

 

[shvet]

Curious why not plastic or coated carbon steel. Less expensive, no corrosion issues.
Note that road tankers are made of carbon steel coated with oil-proof paint. Note that in the past wood was used extensively for this purpose.

 

[LittleInch]

I'm assuming this is a custom made tank and hence easier to fabricate from metal instead of a mould.

But I would have thought some standard tank could be made to fit.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[JohnRBaker]

How about something like this:

https://www.ebay.com/itm/3944067622...ta836tC4k1NrQYSII%3D|ampid:PL_CLK|clp:4429486

John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[EdStainless]

If you look at plastic make sure that the manufacturer approves of it being hauled full of fluid.
Most plastic tanks are not intended for road travel when full.
Ask friends of yours with RVs.
Plastic tanks require a lot of support, like fully supported.
There are options out there in steel, Al, plastic, and SS.
Google

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P.E. Metallurgy, consulting work welcomed

 

[DAVIDSTECKER]

I think I'd take a look at the fuel tanks on refrigerated semi-trailers and see if they can meet your needs or at least pick up some design details.

 

[DAVIDSTECKER]

 

[TugboatEng]

Big fan of fiberglass here. Garolite G-10 shapes with West System epoxy builds nice things. It wouldn't be pretty, do all of the bonding on the outside. That means lots of protrusions.

 

[a50860]

consider the worst-case environment as well. Most metals become brittle in extreme cold, but aluminum actually strengthens.

https://www.shapesbyhydro.com/en/expert-thoughts/in-the-cold-aluminium-gets-stronger/

--
Mitch

 

[LittleInch]

Remember here that our one time poster is:

A) Based in Australia
B) So interested in the discussion that he or she hasn't bothered to look at any responses since 6th Sept.



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Christo_AU]

Thanks everyone for the feedback. I do appreciate it and have been reading them.

PS my question was only regarding why st/st would crack and alum won't but I appreciate all the extra info regarding tanks, very informative.

 

[EdStainless]

You get salt deposits on the out side of the tank.
The salt dries.
You get a hot humid day.
The salt rehydrates and the SS surface temp reaches 140F.
You get pitting, chloride stress corrosion cracking, or both.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[Christo_AU]

Thank you EdStainless. Is this only applicable in countries where NaCl salt is used to melt ice on roads? Or would this happen in dirt roads in Australia with other salts encountered in the soil?

 

[SWComposites]

Aluminum also corrodes. See the bellies of aluminum fuselage aircraft. The susceptibility depends on alloy and temper.

 

[MintJulep]

There are many types of stainless steel. You really need to look at specific types individually to understand how each responses to environmental factors and manufacturing processes.

 

[EdStainless]

Any SS that you commonly find will usually 304 or 316.
A tank in a lean duplex SS (2101) would work great.
Very strong and more corrosion (esp SCC) resistant.

Not just where roads are salted.
Near a coast has chlorides, and many arid climates have lots of Cl (think salt flats).

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[georgeverghese]

Ready made marine grade aluminum gasoline tanks

https://www.kencoracing.com.au/inde...-48l-aluminium-fuel-tanks-105-detail?Itemid=0

 

[TugboatEng]

Considering that tank has no brake or roll formed sides, 6061 would have been the preferred material choice. Why is everybody posting links to non-engineered 10 gallon tanks when OP specifically stated they needed a 50 gallon tank?

https://www.americanmobilepower.com...efer-tanks/aluminum-reefer-tank-50-gallon/172

 

[Joe591]

we made fuel tanks for military vehicles,they were v shaped to conform to the bottom of the vehicle. they were rather large and thus were made from 6mm aluminium plate. why werent they made of stainless steel? maybe cause of weight savings, maybe because they were cheaper. this application was probably diesel though.

for ship use we also manufactured mounting brackets for above deck mounting of cupboards and panels etc.

Also for ship use we built these massive toolboxes with these lids that were bolted down and sealed against water penetration.


while i was with that company we also got truck fuel tanks in sometimes that had sprung a leak and then we did welding repairs on them. that was diesel as well though

the impression that i got was that aluminium is typically seen as a cheaper alternative to stainless steel, but it still gives reasonably good corrosion resistance. the fact that it doesnt spark when struck probably helps too.