Thread: Any sheeties here?

Other questions to ask yourself:

1. How is it to be supported, welded on brackets or a cradle.

2. How is it to be protected against stone impact, thicker sheet or other protection like glued on rubber sheeting.

As an engineer I would also consider adding at least one extra floor stiffener every 200-300mm or so, as a flexing floor will crack welds. I've repaired plenty of mild steel fuel tanks with poorly designed mounts but haven't yet gone near SS.

Hi Jilden, it will be mounted, insulated by rubber, in the luggage compartment beneath my coach, stone impact won't be an issue. It will be secured to 100x100 well braced RHS from which the floor of the luggage compartment is suspended 850mm below the chassis.

Well then the big issue is the flexing of large flat areas. Your chosen fabricator will be the best judge of thickness versus folded in stiffening ribs. Stainless being expensive there's a case to be made to make lighter material do the job of heavier but flat material. Also maximum sheet sizes will determine how well placed long welds are, I'd imagine that 2400 by 1200mm might be the largest sheets you can buy. You might be better off with two 1100mm long tanks linked by taps, allowing you to use two sheets cross wise. End sheets should be arranged with a small lip facing inwards or outwards so they are easier to weld in and don't fracture as quickly.

The grey and black tanks, I'll fab from aluminum but for drinking water I want a food grade stainless.

Two tanks would be a good back up option too.

I'm a metal worker, bee utey has sound advice

304 will be fine for water. It is a very large tank. sheet limitation will be an issue, it would be easier and cheaper to make 2 tanks 1100 long as a sheet of 2400x1200 would work better for less welding and more folding. Having lips folded on edges or end plates adds strength as will help welds from cracking

Personally i would use 2mm thick you might get away with thinner 1.6mm. I Would also suggest it to be purged welded or at least sent of to be electro-chemically passivated.

When it became fashionable to have stainless tanks on Camper trailers, I met several owners who had lost all their water because of flexing of the stainless causing it to work harden then crack along the baffle lines.

Meanwhile my $85 plastic tank soldiered on for about 15 years until some gravel caught in the stone shield wore it through.

I reckon that plastic is a better option, unless you are particularly affronted by taste, which I find hard to notice.
Don't nearly all caravan manufacturers use plastic?

Regards Philip A

Originally Posted by PhilipA

When it became fashionable to have stainless tanks on Camper trailers, I met several owners who had lost all their water because of flexing of the stainless causing it to work harden then crack along the baffle lines.

Meanwhile my $85 plastic tank soldiered on for about 15 years until some gravel caught in the stone shield wore it through.

I reckon that plastic is a better option, unless you are particularly affronted by taste, which I find hard to notice.
Don't nearly all caravan manufacturers use plastic?

Regards Philip A

+1 for plastic tanks, they are pretty much bullet proof that's why most cars these days have plastic fuel tanks.