Hi All. I'm still very green but eager to learn and will appreciate any help. 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 aluminium 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?
interesting.
imho its pretty rare to see aluminum tanks and they tend to have cracking issues because aluminum doesn't handle vibration well and many people don't design them strong enough.
stainless is more common and i've not heard of cracking issues. tho possible if they skimp on materials to keep cost down.
but really the most common trailer fuel tank is plain old mild steel.
imho its pretty rare to see aluminum tanks and they tend to have cracking issues because aluminum doesn't handle vibration well and many people don't design them strong enough.
stainless is more common and i've not heard of cracking issues. tho possible if they skimp on materials to keep cost down.
but really the most common trailer fuel tank is plain old mild steel.
tweak it until it breaks
Probably every fuel tank on a boat is aluminum, so not sure why some people believe them to be rare. I’ve fabricated 4 sets of them in the past year in fact.
Ally or stainless can crack due to vibration. Especially when mounted to a trailer, so that’s a “wash” in why choosing one over the other. I’d venture a guess that due to the substantial weight difference for the thickness appropriate is the predominant reason why someone advised you to use ally.
I’d use 5052 sheet, have as many edges broken using a Break, and weld up the rest. Internal baffles are a very good idea. And if possible, I try to weld the insides and the outsides for added strength. 1/8” filler with 3/16” sheet should be all you need.
Ally or stainless can crack due to vibration. Especially when mounted to a trailer, so that’s a “wash” in why choosing one over the other. I’d venture a guess that due to the substantial weight difference for the thickness appropriate is the predominant reason why someone advised you to use ally.
I’d use 5052 sheet, have as many edges broken using a Break, and weld up the rest. Internal baffles are a very good idea. And if possible, I try to weld the insides and the outsides for added strength. 1/8” filler with 3/16” sheet should be all you need.
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doh, forgot about boats. lets just say with just trailer tanks, probably 90% i see are steel, and a few are stainless. granted most of those i see would be for diesel.
i think the weight saving is more of a perception than reality. its never a "substantial" difference because by the time you use thicker material and more bracing elements, you have used up a lot of the weight savings. (eg going to 3/16 sheet and the baffles for bracing) there is still some, but it depends on the context if its useful or not.Ally or stainless can crack due to vibration. Especially when mounted to a trailer, so that’s a “wash” in why choosing one over the other. I’d venture a guess that due to the substantial weight difference for the thickness appropriate is the predominant reason why someone advised you to use ally.
I’d use 5052 sheet, have as many edges broken using a Break, and weld up the rest. Internal baffles are a very good idea. And if possible, I try to weld the insides and the outsides for added strength. 1/8” filler with 3/16” sheet should be all you need.
eg when its only a small tank on a heavy trailer then the weight savings make next to no difference at all.
i fixed up one of our work tanks a while back. the end baffles where stitch welded and those broke causing the ends to bow out. its only 1/8" so its a bit flexiable so i added a couple gussets in there.
tweak it until it breaks
Like mentioned above, the material is not terribly relevant for cracking. Many times issues like these are caused by improper/insufficient design for mounting the tank to something.
Tank material is sometimes dictated more by the liquid that will be put into it. Eg. Alu tanks don't like prolonged exposure to high ethanol or methanol content fuel as it will start to corrode that. Stainless all the way in that case.
If you look at 'commercial' fuel tanks you'll see that they are either mounted using straps/hangers (optionally rubber coated), mounted on vibration dampers (similar to engine mounts) or when rigid mounted using chunky feet/ear 'plates' and external gussets and overlay plates that work as load-spreaders to interface with the tank skin and prevent stress peaks.
Baffles inside the tank are also a good thing to put in as you don't want that big, heavy, 'slug' of fuel sloshing about and pushing it's weight around. Especially when fitted to a trailer this can make the whole trailer hard to control as the fuel will start to push and pull it sideways making for a very unstable ride down the road. Baffles will slow it's movement.
The weight/inertia of the fuel getting jerked around combined with vibrations can quickly fatigue and crack any tank (often around mounting points/tabs) when proper mounting and baffles are not used. Of course this effect also gets more pronounced as the tank volume gets larger..
Bye, Arno.
Tank material is sometimes dictated more by the liquid that will be put into it. Eg. Alu tanks don't like prolonged exposure to high ethanol or methanol content fuel as it will start to corrode that. Stainless all the way in that case.
If you look at 'commercial' fuel tanks you'll see that they are either mounted using straps/hangers (optionally rubber coated), mounted on vibration dampers (similar to engine mounts) or when rigid mounted using chunky feet/ear 'plates' and external gussets and overlay plates that work as load-spreaders to interface with the tank skin and prevent stress peaks.
Baffles inside the tank are also a good thing to put in as you don't want that big, heavy, 'slug' of fuel sloshing about and pushing it's weight around. Especially when fitted to a trailer this can make the whole trailer hard to control as the fuel will start to push and pull it sideways making for a very unstable ride down the road. Baffles will slow it's movement.
The weight/inertia of the fuel getting jerked around combined with vibrations can quickly fatigue and crack any tank (often around mounting points/tabs) when proper mounting and baffles are not used. Of course this effect also gets more pronounced as the tank volume gets larger..
Bye, Arno.