fuelling practices, undefloor tanks, how do you do yours?

[Ron173]

G'Day all,

recently been experimenting with running low and how much fuel I can get in tank etc.

I always find I struggle to get a 'full' tank and seldom get in the amount I think it will take.

Without going into the size of my tank etc etc, thats not the aim of this thread.... I know there are air pockets, and you never get the FULL capacity, i seem to be about 30% unfilled.

I recently saw a bloke refuelling a medium sized fibreglass cruiser, and he put in 20ltrs then waited a good 2 mins before putting in another, and carried on doing this routine.

I was gonna have a chat but was in a rush, and filled my vehicle and paid when he only had 60ltrs in.

So point of this thread is.... how do you fuel your boat, obviously aimed at underfloor tank boats.

I know it will settle a bit, but surely it settles in about 20secs not 2 mins?

So should I be adopting this blokes routine to get more in?

Interested to hear opinions, but with reasons why you do it your way

Rgds

Ron

[bluefin59]

I have 60lt underfloor and last trip out put in 54 lt ,never have problems waiting for it to settle mine has 2breathers that are viewable if i see fuel coming up shes full ...matt

[Chimo]

Ron

In the water or on a trailer?

Chimo

[Ron173]

Ron

In the water or on a trailer?

Chimo

Always, on the trailer

Ron

[tunaticer]

I would suggest that one of two things are occurring causing your problem. Either your fill line dips lower that the full level of your tank and your breathers have the same problem therefore letting the air in the tank become slightly pressurised and slowing the fill, or the attitude of your boat on your trailer has the fill lines on the lower end of your tank.

A lot of the time it is due to sagged fill or vent lines under your floor pooling with fuel and sometimes getting access is near enough to impossible to rectify the problem. If I was to have a boat built I would have alloy fill lines with a short straight piece of rubber hose fitted between the tank and the filler and breather lines. 2 breathers is definitely the way to go also.

I have a mate who has lots of problem filling his boat and he came up with a solution of sorts. He placed a 2 litre clear tank with a fitting in each end into his breather line. The breather line comes out of the tank and through a small air pump that is used to blow up air matresses and vents out through the normal breather. When he fills up he switches on this little air pump and it creates a slight vacuum in the tank drawing the fuel down the fill line into the tank. He watches the clear 2 litre tank to see if it is filling with fuel as he fills up. So far he hasn't had any enter the clear tank tho. I was concerned about the use of an electric motor and fuel however the entire air side of the pump is sealed and the vapours are all vented outside and not through the air pump motor.

It might solve your problem if it is applicable.

Jack.

[Wahoo]

G;day Ron,
i have a 240l U/F tank and never had a problem with air pockets, but takes ages to fill thou.... lol

Daz

[Greg P]

Yep - no problems filling my 200l tank. Straight in full nozzle till right up the top.

[finga]

I have a too small breather coming out of the tank in the big boat.
It can be a pain in the proverbial to fill but I'am not going to pull it out to fix it.
It also has one of those flush deck mounted fillers.
I just don't push the petrol nozzle right into the filler.
I leave a little gap around the nozzle and the filler pipe so some air can get out there as well. Makes the job not as painful.

On a bright side though Di at the servo used to get a huge smile on her face with the bigger boat parked in her driveway with me standing there for ages. The first time she thought she was going to retire from me.
Now she knows me. Sucker

[Pirate_Pete_Tas]

I had trouble filling with my Polycraft 5.3 when I got it.

I took a photo with my camera in the bilge & found the breather hoses laying on the bottom of the hull as pet the photo.



I spent some time & tied up the breather hoses so they rose from the tank up to the transom & that fixed my problem.

[Chimo]

Hi Ron

My underfloor tank does similar thing even though it has two breathers but both at the rear.

After fiddling around all I do now is ensure that the front of the trailer / bow (front of tank too) is lower than the stern when I fill so the breathers can do their thing.

Easily done if you fill from fuel at home and at the servo pick sites / pumps that have a slope so you can drop the bow.

If your breathers are at the bow end then reverse what I do but either way maybe you can have go and see if you can overcome the issue this way.

Good luck with it

Cheers
Chimo

back

[Twisted_Pair]

I was concerned about the use of an electric motor and fuel however the entire air side of the pump is sealed and the vapours are all vented outside and not through the air pump motor.

Jack.

Hey tunaticer,

Very unsafe practice IMO, there's no way that an air pump designed for inflating air mattresses would have a flame/expolsion proof seal unless it was designed to pump flammable gases.

I would let your mate known to cease this procedure ASAP!!!!!!.

Regards, T_P

[ozscott]

my underfloor tanks (140 litres in total) in my Vagabond have lift up hatches above them and large diameter fillers, so I just get in the boat and fill the tanks directly which ensures that they are to max. The have seperate breathers to the transom and then into one out of the transom.

Cheers

[Leighton]

maybe you're doing what some lady did up Fraser way. She was politely filling the tank on a 12 foot tinnie ( in the water ) while her husband went to pay. He got the bill for $200 odd bucks, it only had a 25L tank on it. His lovely wife had been filling it up through the rod holder.
Fires, police and ambo's, EPA you name it

[megalodon]

Tunaticer.
I can bet one day your mate might beat Richard Branson to low earth orbit. Just hope he does not take other un paying passengers with him including the petrol station. Full tank = big fire few burns and panic and should be a controlable fire. Empty tank = big bang, split tank, split boat, some fire and low earth orbit.

[Ron173]

maybe you're doing what some lady did up Fraser way. She was politely filling the tank on a 12 foot tinnie ( in the water ) while her husband went to pay. He got the bill for $200 odd bucks, it only had a 25L tank on it. His lovely wife had been filling it up through the rod holder.
Fires, police and ambo's, EPA you name it

Thanks for all replies, but this is a ripper!!!

sorry to laugh at someines expense...but hey... I'm sure he looks back n laughs too eh?

thats a top story!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !

Ron