petrol smell

otilly · 26 June 2019, 13:48

Hello,

I have a Scorpion 8.1 mk I; the one without the raised step on the front deck. Bought it in England from a man who went around GB with her in 2004.

The problem; I leave it under a cover in the shadow, tank fully filled up and on warm summer days, like now, I smell a strong petrol fume from under the cover. When I take the cover off, it seems to come from the hatch in the front deck. But that space (anchor, ropes, fenders, etc) is not in contact with the fuel tank.

If I leave the cover off for a day or two the smell is gone, so I guess it's not really petrol leaking, but just the vapor smell. (hopefully)

Can someone explain this?

René

jeffstevens763@g · 26 June 2019, 14:02

vapour comes off petrol all the time more so in hot weather your tank will have a breather for this which also allows air in as you use the fuel,
in my experience when fuel is leaking it burns you eyes because theres so much of it evaporating especially under a cover

otilly · 26 June 2019, 14:06

That's correct but the breather is in the center console, through a hose, which ends outside the console. I put a catch-can in between the hose for the excess fuel which comes out on hot days.

jeffstevens763@g · 26 June 2019, 14:19

fuel shouldnt come out of the breather the breather should be higher than the top of the fuel level is your filler pipe the same level as the breather and your filling the tank up to the top of the filler in which case fuel would come out if you have a good seal on the filler
i would take a few litres out and see how it goes

ribber · 26 June 2019, 15:27

Check the obvious, fuel sender gasket letting by, fuel pick up tube in fuel tank -jubilee clip not split rubber hose. Other joins along the fuel pipe with jubilee clips. Chaffing of fuel lines when passing through the deck rubbing on fiberglass edges.

Old spilled fuel trapped under deck from filling up. If on shore, perhaps flush through with fresh water opening all drain off points. The smallest leak of fuel will cause quite a smell under taup, so best to satisfy yourself there ain't one...

beamishken · 26 June 2019, 17:09

Why not try leaving less fuel in and see what happens. say leave it 3/4 full instead of full it maybe the expansion on a hot day is enough to push fuel up the breather hose

Bigplumbs · 28 June 2019, 16:24

Never leave your tank brimming full

jambo · 28 June 2019, 16:57

Quote:

Originally Posted by beamishken

Why not try leaving less fuel in and see what happens. say leave it 3/4 full instead of full it maybe the expansion on a hot day is enough to push fuel up the breather hose

I would say that is spot on Ken

gtflash · 30 June 2019, 10:38

What year is she? Any pictures of the boat. Is she standard monohull or stepped hull?

Old scorpions have grp tanks. Despite other people’s tanks advise, scorpion recommend a full tank in that scenario. Very few tank failings have occurred as they are made of derekane vinylester resin. Issues arise with condensation if the tanks are left empty or part empty.

You will probably have two round deck hatches. Aft one will be access to middle deck bilge and the forward one a bailey hatch. This one should give access to tank inspection plate. Mine had cork gaskets that had failed, and if trapped water sits on top any minor seal imperfection can contaminate the fuel.

The tanks are usually midship (mine is set back for a race trim) and stretch to the most aft bulkhead of the front/mid locker. The tank roof is not part of the deck, the cable ducts attach to bottom of deck and usually touch the tank roof. it is conceivable that a fuel leak could make fumes forward but It’s unlikely though unless she has been abused or someone doing diy has drilled down through deck and tank roof.

Any problems with water in fuel? Any dripping when ashore from bottom of boat?

otilly · 04 July 2019, 10:51

Hello qtflash,

It's a farmiliar boat for you; you sailed on her in 2004 on the east coast of GB when Ken and the other man came down from cape Wrath. It was called Awesome Fun in those days.

I will open front round hatch and investigate. It's still a mystery to me why I smell such fuel fumes coming out of the front hatch; because it's not connected with the space where the tank is.

gtflash · 04 July 2019, 22:05

Hi otilly. I may well know the boat but didn’t sail on her. Pm me if you prefer. A non raised front deck indicates she is a mk1, so narrower deck and pre 2004ish

The forward bulkhead of the tank is sometimes the aft bulkhead of the rear locker with the built in tanks.

Is the front locker completely sealed floor to roof? The front lockers are inbetween main stringers and should be a watertight compartment. One of my scorpions was and the other not.

Do the fumes also sit under console. The fumes might leak into cable ducts and leak into a non sealed front locker. Cable trays sometimes protrude into front locker.

I really must apologise for the iPad notes drawing. The blue is cable trays. The tank and cable trays on both of mine terminate at bulkhead for front locker. The deck has a void under in the area inbetween main stringers and above tank 50-70mm. Forward of tank it is just a sandwich core deck around 12-15mm thick. Maybe someone has drilled the cable tray to pass a wire into front locker? Or breached the void above tank into front locker?