Fuel over winter

lakelandterrier · 22 October 2011, 10:02

This is new problem for me now I have a 90l built in stainless tank.
My boat will be laid up over the winter months - Nov-March.

What's the best thing to do with the fuel in the tank over winter? I've heard 3 different views:

1) drain (or pump existing fuel out) and leave tank empty (use old fuel in car)

2) Fill it up so there's little room for condensation to develop in the tank over winter, and add some stabiliser

3) fill 1/2-2/3 add stabiliser, then top up with new fuel in the spring to dilute any degraded spirit

ShinyShoe · 22 October 2011, 12:05

As I understood it (1) is considered the best option if you know the boat will not be used all winter. But you need to drain and flush and re-drain before the start of season. If you might want to nip out for a quick spin on boxing day its just not practical.
(2) Is the most common option I've seen suggested, but if you don't use the boat at all (i.e. should have chosen option 1 but didn't) perhaps you'd be best to drain 1/3rd off and replace with fresh fuel. Either storing the "dirty" (in full tanks to avoid condensation) to add back in later in the season or using it in your car with some clean fuel...

(3) just sounds like asking for trouble.

C

alystra · 22 October 2011, 12:22

I have done all of those things over the years. The only thing I would definitely not do again is add any sort of 'stabiliser'. (I'm assuming it's petrol). The one time I did that I had to syphon the tank empty and give it a full clean out with rags and paper towel, clean the pipes and replace all filters. After allowing the fuel to settle in the containers I syphoned the clean stuff out and used it in my car. I was left with litres of brown gunk that had to be disposed of.

Since then I leave the tank half full or more. At the start of the season I use a syphon that reaches right to the bottom of the tank to suck up the water that's accumulated in the tank (I use old fizzy water bottles to collect it in). Usually pump about three litres out, which separates to give no more than a cupful of water and no horrid brown goo. I put the petrol into my car.

I've had no trouble using the old fuel at the beginning of the season, though try to add some fresh to the tank if there's space - doesn't take long to make some if there isn't.

jambo · 22 October 2011, 14:12

I have for years left fuel at various levels and fill up in spring with fresh.
J

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Ribochet · 22 October 2011, 16:12

[QUOTE=jambo;426615]I have for years left fuel at various levels and fill up in spring with fresh.
J

Likewise with no problems - assuming we are talking about petrol - diesel is different where you need to keep the tank full to prevent condensation which encourages nasty microbes to grow

RMT · 22 October 2011, 22:11

Hi
Last couple of years have left tank around half full over winter and have never found water in the filters but do always add at least 40 litres fresh petrol on first use of the new season also run the engine on the hose pipe a couple of times during the winter

willk · 23 October 2011, 22:45

Quote:

Originally Posted by RMT

Hi
Last couple of years have left tank around half full over winter and have never found water in the filters but do always add at least 40 litres fresh petrol on first use of the new season also run the engine on the hose pipe a couple of times during the winter

This worked for me too. Except it was 100L of fresh petrol

williamhorace336 · 24 October 2011, 09:40

I'd go for Option 2.

The same principle as your lawnmower, left un-used over the winter.

Don't top the tank up though, you won't get any fresh fuel in come the new season. Go for 3/4 full.

As the fuel loses combustibility over the winter, just rejuvenate it with fresh fuel at the start of the season and keep an eye on your water filter.

Poly · 24 October 2011, 11:21

IMHO it is all a slightly over exaggerated problem. Starting can be a bit trickier with stale fuel, or is it with extra oil fouling the plugs from winterising? I've seen horrible "glupe" in premixed 2-stroke tanks left for a while but never in neat petrol. Water in fuel is a problem/risk on any boat at any time and not just after storage. Water in diesel, due to diesel bug is more of a concern but the cold of winter will help stop microbial growth.

Good "fuel hygiene" all year round is probably more important than the winter storage protocol.

9D280 · 24 October 2011, 11:30

As Pol says, I've managed to get a '72 vintage johnson to start on premix fuel that in the aftermath we worked out had been lying for about 4 years.

The simple answer is wear a couple more jumpers and go out & enjoy the place to yourself!

Erin · 24 October 2011, 13:45

A bit of condensation is obviously a risk, but that's what fuel/water separator filters are for. I really doubt much humid air will get into an underdeck tank over a winter period (unless it's very foggy and you have two vent pipes to allow circulation), and to date I've never worried about it. Any water that is there is more than likely from the petrol supplier's tank, not yours.

I just leave my tank at whatever fuel level is in it at the end of the season and then fill to the brim on first launch of the next season.

Diesel is a different matter, so you would brim that before storage to minimise the risk of bug.

lakelandterrier · 29 October 2011, 17:08

Thanks for the advice everyone,

I'll leave the tank wherever it is c. 1/2 full top up in the spring & not worry.

Last day of our season was yesterday - and what a day - clear, no sea to speak of sunny and fanststic light. Launched Brixham and were off Teignmouth for lunch only 30 min later! Though of pushing on to Exmouth, but didn't want to tire the children too much or get back too late.

mick · 02 November 2011, 22:50

I asked the question at Redbay and they said leave it full

Broomy · 03 November 2011, 00:16

Hi, dont know how aware everyone here is re the probs with all the fuel companys increasing the Ethanol content in the petrol we are buying to 5%.
My other expensive hobby is motor bikes, one being an older 1970s Triumph, the whole classic/vintage motorcycle enthusiast group have been having 'Major' problems for 12 months or more with the Ethanol damaging fuel lines, fibre washers, and desolving tank sealants, blocking jets, etc, and causing engine damage, it will actually distroy a fibreglass tank !! The Ethanol actually attracts moisture, so laying up is going to become a bigger problem.If you search Ethanol on this site, and the internet, lots more info.
I have used STA-BIL fuel stabiliser in both bikes and my rib, with no bad results, I belive that there is a new form of marine stabiliser available in the States which is more effective than the form we can buy it here, and have heard it can be imported by the firm called FORCE, which build inflatables I think. The classic bike clubs I am a member of, are lobbing MPS about this problem, its one of the fuel companys biggest scams yet, and its going to get worse, unless we do somthing about it....