Diesel Fule Tank Float

[Little Dorrit]

I am making a small 2/3 mm diameter spehrical float to go in a a clear plastic fuel level indicator pipe which connects the top and bottom of my fuel tank.

Would anyone know if cork is likely to absorb diesel or perish quickly?

Thanks

 

[vyv_cox]

Cork gaskets work well on fuel tanks.

 

[rob2]

When I bought my boat the surveyor was very much against the sight tube fitted like yours between the top and bottom of the tank. In the event of a fire, the sight tube would melt and dump the entire content of the tank onto the flames. As a modification, I sealed off the top connection and put a tap on the lower spigot, leading to a sight tube from a domestic fuel oil tank. This is open at the top end, well above the tank top and has a momentary push-to-open valve at the bottom end so that the plastic tube, if melted, can only dump its own volume of fuel. Another guy did something similar with a copper stand pipe vented at the top and containing a vertical fuel sender.

Rob.

P.S. Vyv, would a cork gasket seal on an inspection hatch on the side of a diesel tank and what sealant to use?

 

[vyv_cox]

P.S. Vyv, would a cork gasket seal on an inspection hatch on the side of a diesel tank and what sealant to use?

Cork is widely used for this type of seal, available in sheet form at motor factors. The usual type for this is bonded with nitrile or neporene, there may be others but I would avoid them for this job. Ebay has many sellers.

Hylomar Blue is probably the best sealant available and will do a good job on virtually everything on the boat.

 

[rob2]

Thanks, Vyv.

Rob.

 

[prv]

When I bought my boat the surveyor was very much against the sight tube fitted like yours between the top and bottom of the tank. In the event of a fire, the sight tube would melt and dump the entire content of the tank onto the flames.

You can get a special fitting for the bottom of sight tubes, which incorporates a push-button to connect it to the tank and read the level; the rest of the time it's closed so that the tank won't empty if the tube is broken.

I think I saw it in the BES catalogue for use with domestic heating oil tanks.

Pete