Wansworth
Well-known member
Aboard a yacht last week and the owner remind stainless steel was not the best for fuel tanks from the condensation point of view,better plastic?
Best material for fuel tank
- Thread starter Wansworth
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lusitano
Active member
Polyethelyne every time, no corrosion and minimum condensation
Tranona
Well-known member
Plus one.
vyv_cox
Well-known member
If the available space fits a plastic one I agree it would be my choice. A stainless steel one built correctly using the correct sheet and filler rods is perfectly good. Mine is now almost 40 years old and as good as the day it was made.
john_morris_uk
Well-known member
My fuel tank is stainless steel. I understand it’s illegal to fit a stainless steel fuel tank in a boat in the USA but I’m not there so who cares. No risk of condensation where the boat is atm but when it’s back in cooler climes, it’s got a sump, fuel sampling point & valve from the sump and the pickup lines are above the bottom of the tank. Then there’s a water separator in the fuel line… etc.
It replaced a mild steel tank that had gone v rusty.
I’d consider plastic but I’m not sure it’s that much better?
It replaced a mild steel tank that had gone v rusty.
I’d consider plastic but I’m not sure it’s that much better?
Tranona
Well-known member
See Vyv's comments above, particularly the word "if2". Having had a weld on a stainless tank fail on our trip back across the Med I would prefer a Tek Tanks custom made. Not so sure about the rotary moulded types although it is often the fitting attachments that give problems not the tank material itself.
geem
Well-known member
Grp diesel tank built as part of the boat. 500 litres. Perfect after 44 years and lots of miles. A manhole you can climb in to if you want
Tranona
Well-known member
Fine but impossible on most boats - and many who have that from the early days of GRP boat building might not agree with you. Not good to extrapolate from one example.
Wansworth
Well-known member
Yes built in grp fuel tanks obviously seemed a good thing and could occupy an awkward corner
geem
Well-known member
Utter nonsense. A well built boat is a well boat. Not my problem if that's not your experience.
geem
Well-known member
It's great for maximising the size of the tank and adding structural strength to the hull. Our fuel and water tank occupy the space under the saloon floor. They use every spare bit of space and waste nothing. Our water tank is the same and the holding tank. I notice on the utube channel Duracell, they have the same set up using ballast tanks converted to large water tanks. It's not a cheap solution, but done well, it's excellent.Yes built in grp fuel tanks obviously seemed a good thing and could occupy an awkward corner
Wansworth
Well-known member
My limited experience on three French yachts from the 1970s was built in tanks in awkward corners with no access to clean
geem
Well-known member
This one is the water tank. 800 litres. Two access lids. You can see that you can climb in. The diesel tank is just astern. 500 litres. Only a single access lid on that one
PetiteFleur
Well-known member
I've also got a moulded plastic, which replaced a mild steel tank which leaked when I got my boat several years ago. Never had a problem with it, it was was much cheaper than a stainless tank. The original steel tank was over 40 gallons capacity, replaced with a 19 gallon tank which gives me over 28 hours with the replacement engine, and gave room for the calorifier in the fuel locker.
Gustywinds
Active member
And you keep your galley slave in it too?
LittleSister
Well-known member
I don't think stainless tanks should be so casually dismissed. As others have mentioned, they need to be properly welded, but I can't imagine they are any worse for condensation that non-stainless steel (which of course suffer rust problems - I'd avoid those), nor significantly worse in that regard than GRP. Moulded plastic might be marginally better for condensation, but condensation really isn't a big issue.
The best tank I've ever had in a boat was a stainless one. Over 40 years old but still shiny inside (and out) so you can see any debris in the tank. Its other advantages were a drain right in the bottom, a straight drop from the filler into the tank (for visibility and facilitating dipping the tank), and being separate from the boat structure and bolted to the hull side, so that when some fool (no names, no pack drill
) left the filler cap off and I got sea water in it, it was an easy task to close the tap, remove the hose, unbolt the tank and take it elsewhere to empty and flush it.
Of course, if you need an excuse to reject yet another potential boat, it's as good as any other.
The best tank I've ever had in a boat was a stainless one. Over 40 years old but still shiny inside (and out) so you can see any debris in the tank. Its other advantages were a drain right in the bottom, a straight drop from the filler into the tank (for visibility and facilitating dipping the tank), and being separate from the boat structure and bolted to the hull side, so that when some fool (no names, no pack drill
) left the filler cap off and I got sea water in it, it was an easy task to close the tap, remove the hose, unbolt the tank and take it elsewhere to empty and flush it.Of course, if you need an excuse to reject yet another potential boat, it's as good as any other.
Wansworth
Well-known member
Thank you,it was just an interested questionI don't think stainless tanks should be so casually dismissed. As others have mentioned, they need to be properly welded, but I can't imagine they are any worse for condensation that non-stainless steel (which of course suffer rust problems - I'd avoid those), nor significantly worse in that regard than GRP. Moulded plastic might be marginally better for condensation, but condensation really isn't a big issue.
The best tank I've ever had in a boat was a stainless one. Over 40 years old but still shiny inside (and out) so you can see any debris in the tank. Its other advantages were a drain right in the bottom, a straight drop from the filler into the tank (for visibility and facilitating dipping the tank), and being separate from the boat structure and bolted to the hull side, so that when some fool (no names, no pack drill
Of course, if you need an excuse to reject yet another potential boat, it's as good as any other.
Sandy
Well-known member
Has anybody done any scientific testing on the amount of condensation that actually collects in a tank?
The amount of 'fresh air' that enters a tank in 24 hours is tiny.
The amount of 'fresh air' that enters a tank in 24 hours is tiny.
oldgit
Well-known member
Over the years all have proved to have had their little problems.
Moulding a fuel tank into the hull would appear to be a no brainer using the miracle of glassfibre and of course it saved the cost of custom fabricating and installing a cutom tank.
More commonly found in motorboats the glassfibre fuel tank came and went .
Moulding a fuel tank into the hull would appear to be a no brainer using the miracle of glassfibre and of course it saved the cost of custom fabricating and installing a cutom tank.
More commonly found in motorboats the glassfibre fuel tank came and went .
NormanS
Well-known member
It's very difficult for a tank, moulded as part of the hull, to have a sump with a drain valve.
