Condensation Options

[poly]

can any of the members help me, after reading about J G's trouble with water in the fuel i checked my two tanks and found a small amount of water in each is there a way of preventing this from happening???????????

[Jumpus GooDarus]

You can leave your tanks full but I dont like doing so.
It's bad enough on a alloy boat let alone a plastic one by that I mean come summer & the hot days your fuel will want to escape due to the heat a few times ages ago I sat & watched fuel come pissing out of my breathers when I had full tanks, didn't like that @ all fuel around the boat to dangerous so I stoped leaving my tanks full.

Not alot you can do to stop the condensation but you can fit water seperators to your fuel system they were the 1st things I looked @ when motors cut out & sure enough full of water didn't check them when I started the motors they kicked over 1st turn of the keys as there was good fuel in the lines & injection system but when that run out the water got pushed in & you cant compress water.

Still haven't drained water from that bad tank was going to do it 2day but had alot of running around to do & it was getting near dark when I got around to the boat a bit of a bummer cause I wanted to get out after the YFT tomorro.

They have to wait cause what I want to do is permanently mount a electric fuel pump in the boat I have the pump reason for this is if I ever cop water like last time again I can flick the switch pump out the water till fuel starts to feed back into bowl

[Jumpus GooDarus]

Cleaned out the tank with water in it today wouldn've already have drained about a litre & a 1/2 last week on the water & another 1.5 litres came out today took a pic just to show those not aware how the water sits on bottom & fuel floats on top

[Fed]

But did you find the leak mate?

[Jumpus GooDarus]

Fed there's no leak

But I'll tell you what I wont have any probs draining water out of tanks if they ever cop water again, came up with a spoofy idea drilled & tapped bottom of seperators & screwed a ball valve into it, then screwed a 5/16 barb into the ball valve to which I can attach the full pump @ any given time.

Originally I was going to use the spare inlet on the filter but after a bit of thought saw that was not such a crash hoy idea cause if there was water in the seperator it would remain there , pumping from yje bottom gets rid of the water 1st

[Fed]

Water in the fuel from the servo just doesn't make sense, if that was the case then you should have got a tank full of water or none at all.
The chances of getting just a couple of litres of water would be enormous knowing that petrol floats on water.
No way you got a couple of litres of condensation either.
Go and fix your leak mate. LOL!

[jasonb]

they reckon you can put metho in your cars tank and it stops water ,or you can get stuff for motor bike tanks that lines the inside of the tank ,i think its a rubber or plastic that sticks to the tank and stopps them from rusting so ide say that it stops water as well

[Jumpus GooDarus]

I know that bloody Fed is Gee'n me up but for the rest of.
1st of all if a swervo's tanks are low you will be buying water their tanks fill you up from the top & not the bottom they have some sort of floating pickup but if their tanks do run low then you will be buying water.

Some mates of mine filled up their shark cat @ one servo years ago & I had to tow them back to ramp we ended up pumping well over 200 litres of water out of their tanks.

Now back to my water prob well I've got stainless steel tanks under floor & believe they're more septable to condensation than alloy tanks never had a prob when I had the alloy tank underfloor but @ one stage I did have 2 stainless steel Above floor tanks on the boat & recall on a few occasions copping heaps of water in those but being above floor made it very easy to drain the water out all I had to do was take the clamp off the fuel plug & the water would flow out.

Getting back to leaks !

If I or anyone else had a leak then you'd smell the petrol such was not the case with me but have to admit 4 litres was alot of water.

they reckon you can put metho in your cars tank and it stops water

Yep metho will evaporate the water but I dont like the idea of putting metho in my fuel back in the old days I had a mate who used to metho inject his torana XU1 but cant recall to much about it

[Fed]

Some mates of mine filled up their shark cat @ one servo years ago & I had to tow them back to ramp we ended up pumping well over 200 litres of water out of their tanks.

Sure, that sounds like a servo problem.

When I say leaks I mean a leak high up in your tank that allows water to get in, probably around the filler cap/hose or around your breather so you wouldn't expect to smell it anyway.

[Jumpus GooDarus]

Breathers are situated on transom & the water would have to travel up hill 5 meters to get into the tank thats impossible.
Already said fillers are on the gunnels & that they are raised cap screw over the top of them & a O-Ring ensures no water gets in that way so thats impossible as well

Any More Suggestions ?

Ed I basically built that boat & know all the inns & outs so take my word on it when I say water couldn't have possibly gotten into the tank/s unless it came from the servo it it was condensation

[Fed]

You got a hose between the filler point and the tank held on with a hose clamp?
What's your o ring like?
Not quite sure what you mean by "raised cap screw over the top of them".

[Jumpus GooDarus]

ED when I rebuilt the boat I did a neat job I hate loose ends & eyesores everything has a place to be put away & I spit the dummy if people leave things lying around.

these are my fuel fillers in order for water to get in the water has to sneak under cap force it's way up about 10 mm to get into the hose a bit hard when it's also got to navigate the O-Ring under the cap.

I have no hope clamps exposed all the hoses & clamps are concealed behind a panel & not even the gernie under pressure could throw water onto them add to that the boat is always parked with nose up so if it rains all water drains to the rear

[Fed]

Can water get between the deck and the filler fitting, did you form a complete silicon seal under the fitting at installation?
If not it may be running from there, down to the outer side of the filler spigot and laying in the area where your flexible hose isn't clamped on tight enough.

How's your ring??? LOL!

[Fed]

Poly, are your tanks built in, is your boat stored under cover?

[poly]

Fed no the tanks are not built in but are stored in the two 70lt boxes at the back of the boat well protected from spray and yes it is stored under cover

[Jumpus GooDarus]

Geez Fed you dont want to believe in condensation do you ??

Have you ever owned a air compressor ??

What happens if you dont bleed the tank ??

You Get Bloody Water Coming Out Of Your Airlines Dont You

[Fed]

I've owned a few compressors but they're not really a valid comparison.
It's not that I don't want to believe in condensation but 3 litres in a 150 litre? tank is a bit hard to swallow.
BTW, why don't you pour off the fuel in that jar & taste the water just in case it's salty.
Could you be pushing water up your breather pipe when you launch the boat?
How's your ring?


How much water Poly, I think I'd tip it out, give the empty tank a rinse with a little metho & start again keeping a careful eye on it.

This post has been edited by Fed: Jul 16 2007, 11:32 AM

[Jumpus GooDarus]

You must think I'm silly Fed ?

Tasting the water was the 1st thing I did & it was NOT SALTY

The difference between a air compressopr tank & a fuel tank is simple air compressor tanks are less likely to condensate the air & turnit into water simply because they are sealed.

Both work on the same principal HEAT is what turn air into water, you leave your compressor tank full of air & dont intoduce new air you wont get anywhere as much water have a small leak in your airline system then see how much water is in the tank.

One think I noticed back when I had the big compressor running the factory on those really hot days we'd have to bleed the water out of the system up to 3 or 5 times a day.

Now last time I used my boat was 6 weeks prior to last weekend alluminium is one of those materials which can really retain heat ever stood on metal bare footed when it's been out in the sun ??????

Well to give you another example we used alluminium plate as chill bars when Tig Welding Stainless is absorbs most of the heat which stops distortion in the the stainless not only that it retains the heat as well for long periods of time it'salso the reason why Alloy is used in cooking pot & pan the better quality ones these days are stainless but have a copper base.

Now picture my hull all alloy with a sealed floor you've got one big baking chamber when the sun is out my tanks are under floor in that chamber so what happens to the air in the tanks ????

[SUMOFISHIN]

You must think I'm silly Fed ?

Thats not a smart way to start your post you could get some Honest responses

This post has been edited by SUMOFISHIN: Jul 16 2007, 01:54 PM

[hustler57]

this may be a slight change of topic but i thought id add it in here,

another bad bad thing to do is fill ur boat up or even your car while a fuel tanker is filling up the storage tanks at a fuel station as it mixes up all the crappy stuff at the bottom of the tanks and the water as well,

[Jumpus GooDarus]

Thats not a smart way to start your post you could get some Honest responses

I may fool around & act silly SUMO but when it comes down to the nitty gritty & applying logic there's not to many better than the Jumpus I've generally got a reply for everything

[SUMOFISHIN]

There you go JUMPUS, you have been listening and learning.

[Fed]

Have a read Jumpy.
Applied Logic

How's your ring?
What is the height of your breather compared to the height where it enters your fuel tank?
Do you get water in both tanks or only one?
How well is is your deck filler sealed to the deck?

If you can't find a leak anywhere then we should firebomb the servo for selling water as fuel.

[hustler57]

hmm, im of the idea that the water came from the servo, every sercie stations fuel storage tanks underground have got water in them, and if they say they dont then they are flat out lying, i have always said and always will say be very carefull where you buy your fuel from, and thanks to caltex for the discount fuel ouchers im affraid its just gong to get worse, but thats another topic for the future ,

[Jumpus GooDarus]

Well what can I say Ed ?

Except that guy who wrote that crap David Pascoe is a Big Moron

The internet is full of gooses like him voicing their opinion & I only skimed what he had to say cause it was giving me diareah.

I'll tell AGAIN there is no possible way water could've gotten into the tank on it's own accord it was either pumped from the bowser or it's condensation.

I've already stated I have a sealed floor in my boat & alloy retains heat very well now let mme ask you a simple question

What happens if you have say a air conditioned room with a large window & all of a sudden a heat wave comes through your glass is single sheet not vacum sealed twin glazed.

Will you or wont you see condensation running down the glass ???

Mate I built commercial refrigeration for a living & know more about condensation than than twit David Pascoe

[Spudly]

you have had Alot of jobs in your many years jumpy.... what else have you done!?!?

(im not doubting you here, its obvious that you have had alot of experiance in many things simply by the work you do on your own boats and home)

Back on topic, A friend of mine drives fuel tankers, has done for many years, he might be able to shed a bit of light on th topic, as could our resident chemists on site. I might put this to them and see what they come up with.

[Fed]

That would be good if you can get one of those chemists RDNR, I don't think Jumpy will ever believe he has got it wrong.
I'll say it again, to condense a gas into a liquid you COOL it.
Air conditioners, refrigeration,.... the gas is COOLED in a condensor to change it into a liquid.

A simple test, pull a stubbie out of the fridge and watch the water condense on the outside of the bottle.

I've never said I don't believe in condensation inside fuel tanks, it's the 3 litres of water that condensed out of a 150 litre tank that I can't swallow.

[Jumpus GooDarus]

Ed I dont think you've read anything I've said or you haven't understood it ??

I'll run throught it again

Originally I said that I thought the water came from the servo @ that time I'd drain around 1.5 litres out maybe 2 & that was done on the day the motors stopped out on the water I gave up after that cause I didn't know how much more was in there & just ran the freshly filled tank.

Last Sunday I finally got around to draining the remaining water out as per pic theres around 2 litres of water in that jar so total we're talking around 4 litres

Mind you I never ever claimed all that water was condensation & still believe it came from the servo it was STEVE.P who said it couldn't have come from the servo not me.

I merely resposded to your claims that you cant get water in your tank via condensation & gave you examples of how H2O can tun into water after all thats what it is water ! & certain temperature conditions yes H2O will turn into water & since water in liquid forn is heavier than air it will sink to the bottom of the tank.

Like I said on numerous occaions there is no possible way water can get into my tanks via rain etc you can come down & have a look for yourself if you dont believe me

A simple test, pull a stubbie out of the fridge and watch the water condense on the outside of the bottle

Thats exactly what I've been trying to tell you heat against cold will cause condensation & it can occur inside the tank my hull is sealed & can get pretty hot in there I always leave the bung plug out to air the hull same can be said about the fuel tank breather lets the tank release pressure & thats why I never leave tanks full I 've fuel pissing out of the breather on a hot day with full tanks.

Still dont & wont know how much fuel is in that tank till I fill up next time I'm sure there's over 100 litres in there now if had a few really hot days & that fuel level rose up near the breather outlet aren't you compressing the air in the tank ??????????????????????

[Fed]

Just to be clear...

1) You cannot condense 3-4 litres of water from 150 litres of air as that would make 150 litres of air weigh 3-4 kilograms.
2) The chances of getting 3-4 litres of water from the servo would be very small to say the least.
I'd be interested to know exactly how the fuel is picked up in the servo tanks...anyone?
3) If you had 3-4 litres of water in your tank then go and figure out where the leak is.

[Spudly]

I beleive tanks at petrol stations generally pickup from a floating pickup on the surface level in the tank?

Jumpas, what if you used som kind of water seperator on th breather? im trying to think how to explain what i mean, Umm, Some kind of filter to stop the moisture coming into the tank as it breaths?

Like some people run on the diff breathers on 4x4's?

Ummm, ill keep thinking and get back to ya

[Spudly]

May I add, the best way to avoid condensation in the tanks is to keep them full..

[Spudly]

Water gets into your gasoline via condensation. That condensation might happen within your car tank or within the tank at your gas station or even from the tanker that brings the water to the gas station.
Condensation forms when warm moist air is cooled down. For example, when you drive your car on a warm moist day, then the warm air is sucked into your gas tank as your car uses gas. Then at night when the car cools off, if the temperature drops below the dew point of the air in the tank, then water will condense from the air into the tank, hence into the gasoline.
This same mechanism accounts for water in the fuel tanks at the gas station or tanker truck.
By the way, it is a bigger problem for airplanes. Also for an airplane water commonly gets into the fuel tank via rain water that leaks into the tank around loose fitting fuel caps.
For your curiousity, the density of water is much greater than that of airplane fuel. So everytime before you fly a plane you check for water in the tank by draining fuel/water from a valve at the bottom of the tank.

[Jumpus GooDarus]

Not even going to bother replying to Fed's theory about a leak cause there isn't one

Nor his other theory that you candense 3 - 4 litre of water because you can.

Ed if you choose not to believe in condensation thats fine with me but I recall back @ SF you were inquiring how water got into your fuel tank maybe you should check for leaks

Rum you hit the nail on the head & it's what I've been saying all along condensation only occurs with temperature change wont just happen like that in my case the boat hadn't been used for some time & who knows when I actually filled up that tank last with these 4 Strokes they use bugger all fuel & I could get up to 10 + trips out of one tank if I'm only fishing in the Bay or local.

By the way, it is a bigger problem for airplanes

Depends on which airplane your refering to the turbine engine jets use a kerosine mix not petrol like we do & yes they would be subject to a hell of alot more condensation temperatures up there drop well below freezing point in order for controls not to freeze up heaters are used to thaw out the ice

[Spudly]

there not my words, but ill happily take credit, Its off one of the Fuel company pages.

[Fed]

Ed if you choose not to believe in condensation thats fine with me but I recall back @ SF you were inquiring how water got into your fuel tank maybe you should check for leaks

I believe in condensation it's just that I don't believe it's causing your problem because 3-4 litres is too much.
My fuel problem was stale fuel not water in the fuel no water was found when I drained the tank.

One thing I did find though was that lifting the front of the trailer/boat up as high as it would go enabled me to drain an extra 5 or so litres out of the tank which is not normally retrievable under normal operating attitudes.
That gives me a huge water trap in the bottom of my tank so that's a good thing.

Are we having fun yet?

[Jumpus GooDarus]

OK I'll see if I can convince you one last time this is fair dinkum & I'm not pulling your leg either.

Going back prob 7 years now same boat sat idle @ my workshop for about 2 1/2 yearss mind you it was inside & out of any rain I mentioned them earlier back then I had 2 above floor tanks each held approx 130 litres they were made out of stainless.

I also had one underfloor which held 140 litres & another which held 100 litres reason for so muchfuel was back then I used to fish the Canyons off Pt Stevens & it's a bloody long way out esp back then with the 2 strokes they chewed the fuel on a flat day with the hammers all the way down.

Anyways the reason the boat sat there unused for so long was because back then I had the big moored boat, one day I decided to take it out for a run the above floor tanks would've been about over 1/2 full got to the ramp & they wouldn't start quick check found water in fuel to be the prob bled the carbs & it was easy to drain the water from the tanks being above floor just had to undo the clamp holding fuel fitting to hose & with the boat using the angle of the ramp it just gravity drained out.

Each tank had approx 15 litres of water in it filled nearly 2 10 litre bucked out of each tank

[Fed]

It probably rained before you put the boat under cover for 2½ years, or you used the same servo.

You cannot wring 15 litres of water from 130 litres of air!

If it was possible to do that then we could use your tanks instead of building a desalination plant.

[poly]

yes u can fed if like most most boat owners it sits idle for a wile it builds condensation up to the point of trouble and in the masters case he has been working on that rebuild for so long he could swim in condensation for life so remember if u are not using them fill them.
it is a shame the over flow from the tank will stain the paint on alloy boats but that is the price u must pay for geting second best.

[Jumpus GooDarus]

Dear Mr Fed

Obviously my attempts to convince you that condensation does occur in fuel tanks has fallen on death ears even with the assistance of Professor Rumpy Dust N Ruckus who's valliant attempts to collect reliable information & data again fell on death ears instead you chose to take the word of a unreliable source some Dingaling called David Pascoe who most likely didn't even make it past primary school.

Unlike myself whom was educated @ The University of Beijing under the guidance of Professor I Te Chu a world renouned figure in condensation reseach, hence I came to the conclusion that you could only be one of those terrorist doodies so I ran your description through interpol & was surprised nothing came up.

At a loss as to your motives it then occured to me that you're one of those Greenies & I can only assumed your sole purpose in this thread is to convince fishermen it is safe to assume condensation dosen't happen &^ it is completely safe to run the motors on water.

But the peeps here aren't that silly & they know better, by the way that hole you are digging yourself into can only lead to one place ?

China

Where I'm pretty certain Professor I Te Chu will be on hand to greet you & give you a ride down to Tiananmen Square where some tanks will be on hand to give you a 21 gun salute

[Fed]

I believe in condensation it's just that I don't believe it's causing your problem because 3-4 litres is too much.

What part of that don't you understand?

I'm going to Bunnings today to buy a bigger shovel.... I'll be back.

Are we having fun yet?

[SUMOFISHIN]

If you blokes could just put all this effort into making outboards run on water we would all be able to go fishing anytime without spending money on fuel. and I will give you a thousand dollars to convert my engine, you will not only get Wealthy! you could be very Wise.

[hustler57]

well well well,

isnt this an interesting thread, i reckon we should all agree to disagree on this matter,

personally i believe there are only 2 ways for water to get into a fuel tank ,

1st way , there would have to be a leak in the fuel tank for water to enter the tank

2nd way, and i believe this is to more likely way, water would have to enter the tank thru being mixed up with fuel from the service station, every fuel station has water in there tanks,

lets agree to disagree

[Fed]

There is another answer.... CONDENSATION!
But only if Jumpy's fuel tank holds 100,000 litres.
Read it and weep.

[STEVE.P]

well well well,

isnt this an interesting thread, i reckon we should all agree to disagree on this matter,

personally i believe there are only 2 ways for water to get into a fuel tank ,

1st way , there would have to be a leak in the fuel tank for water to enter the tank

2nd way, and i believe this is to more likely way, water would have to enter the tank thru being mixed up with fuel from the service station, every fuel station has water in there tanks,

lets agree to disagree

there could be a 3rd way hustler . mayby fed took a leak in them
And the mini series continues tomorow ,

Will Fed agree or disagree, :huh: Can JG recover after all it was browny colour liquid

Will FED agree to a urine sample , :o

this is C D S , tune in next time

:mellow: :huh: :o

[Spudly]

you got to remember fed, that it didnt do the 3 litres overnight.. it had a few weeks to do it and each day the the tank would expand in the heat, sucking in the air, which then cooled and put a small amount of water in, the next day the same thing and so on, so over time its possable for this amount of water to get in.. Another solution might be to close the breather (plastic tank caps normally have a screw that you can close) however you run the risk of stressing the tank as it expands and compresses in the heat/cool..

[Fed]

Even if conditions were perfect for condensation every night JG would have to have 1000 x 100 Litre air changes to get his 3 litres, that's why combined with pressure his air compressor condenses so much when it's continually running, it has a continuous supply of moisture laden air.
Remember an 'average' compressor will pump maybe 20,000 Litres per hour x 8 hours = 160,000 Litres which could result in 4-5 Litres of condensation inside the compressor tank.
It's good to see you questioning things though RDNR, Jumpy needs to realise we are only trying to help him.

[Spudly]

Yea, i must say, im no expert on i at all... just trying to look from both sides...

It is definatly making for a good topic though...

[Jumpus GooDarus]

well well well,

isnt this an interesting thread, i reckon we should all agree to disagree on this matter,

personally i believe there are only 2 ways for water to get into a fuel tank ,

1st way , there would have to be a leak in the fuel tank for water to enter the tank

2nd way, and i believe this is to more likely way, water would have to enter the tank thru being mixed up with fuel from the service station, every fuel station has water in there tanks,

lets agree to disagree

Why Do You Think I Seem To Argue With Everyone ???

Nothing wrong with disagreeing with peeps see what's happened here if everyone agree's with one another all the time then topics die

OK one more time for Fed

Now Fed do you agree that water will settle @ the bottom of the tank ???
When it does this does it make way for new condensation to occur ????
Over a period of time in my case a couple of months why cant 3 - 4 litres accumilate in the take bear in mind we had alot of rain hence there was alot of moisture in the air.

Getting back to my boat went out for a fish yesterday & filled up both tanks earlier I mentioned I had no idea how much fuel was actually in the tank which gave me grief.

Well turns out there was just over 110 litres in there so it was 2/3's full I did cop a touch more water in the seperators yesterday but that could've been because I didn't change the filters they can hold a fair bit.

Other than that the new mods to the seperators worked a charm just a flick of the valve & the water was gone

Bear in mind guys I've owned this boat well over 15 years know it inside out & in all that time only on one other occasion did I get water in the fuel & as like this time it was in the stainless steel tanks never ever had a prob with the alloy tanks that were in the boat from day one or the other alloy tank which I built starting to Q if it was a wise idea to have made the new tanks out of S/S

[Fed]

Now Fed do you agree that water will settle @ the bottom of the tank ???

Yes, I've never disputed that.

When it does this does it make way for new condensation to occur ????

No, you have to get 'new' air with 'new' water content in it.

Over a period of time in my case a couple of months why cant 3 - 4 litres accumilate in the take bear in mind we had alot of rain hence there was alot of moisture in the air.

Because the water content from say 100 Litres of air is only 2-3 grams (a tiny amount), you would then have to replace the 100 Litres of air with 'new' air and condense again..... every night.... in perfect condensation conditions....
for 1000 nights to get 2-3 Litres of water.
It's just not feasible to be condensation in that quantity.

Well turns out there was just over 110 litres in there so it was 2/3's full I did cop a touch more water in the seperators yesterday but that could've been because I didn't change the filters they can hold a fair bit.

I was giving you as much leeway as I could so I was working on your tank being 1/3 full, but because it was 2/3 full then all the previous numbers need to be doubled as the air capacity of your tank just halved to just 50 Litres instead of the 100 Litres I've been allowing for.

If condensation was happening to the degree you're talking about then half the cars in the World would be stopping from it. I can't say I've ever heard of a car suffering from condensation in a fuel tank yet it should be more common than flat tyres according to your boat tank.

[Jumpus GooDarus]

No, you have to get 'new' air with 'new' water content in it.

Dosen't that occur naturally ?? all you need is a bit of a hot hot day & the fuel inside your tank will expand & when it settles back down again say when it cools down of a nightime fresh air is sucked back into the tank via the breather bear in mind also depending on the day dew occurs @ that time of the day as well.
After all that is the whole purpose of the breather to relieve pressure by the way my breathers are 1" in dia, if you dont follow what I've just said go get yourself a container fill it with fuel & seal it then see what happens to the container shape.

Because the water content from say 100 Litres of air is only 2-3 grams (a tiny amount), you would then have to replace the 100 Litres of air with 'new' air and condense again..... every night.... in perfect condensation conditions....
for 1000 nights to get 2-3 Litres of water.
It's just not feasible to be condensation in that quantity.

Think I answered that in last paragraph, you seem to think it's the same air in the tank constantley which is not the case

If condensation was happening to the degree you're talking about then half the cars in the World would be stopping from it. I can't say I've ever heard of a car suffering from condensation in a fuel tank yet it should be more common than flat tyres according to your boat tank.

Again you're working on the assumption that it's the same stale air in the tank @ all times & thats not the case as in the case of the tyres which have a valve to keep same air in @ all times.

Fed try looking @ the obvious theory that breathers allow air to enter & leave tank @ will

[Fed]

I completely agree with you, the tank will breathe as the temperature changes but how much?
I'd guess about 10% would more than cover it and that amount is nowhere nearly enough to explain the quantity of water you had in the tank.
Even a 50% air change every night will not explain it.
There's not much more to say about this unless someone else can add some input, perhaps we should call in an expert from a scientific forum, there's plenty of them out there.
If you're happy to live with it I say good for you, I wouldn't.

[Fed]

BTW, being a 1" breather I'd be looking at that very carefully remembering that the transom outlet must be way higher than where it fits into the tank.
Are you sure the water can't get in there mate?

[Jumpus GooDarus]

Only time will tell Fed.

Like I said occationally I may have to drain a little water from the seperators but nothing like what happened that day

The last trip I'd done prior to that was down to The Hump & recall running out of fuel on the front tank & switched over to the rear tank & there was no water or very little in the seperators else the motors would've stopped on that day & they didn't.

When I started them up a couple of weeks ago then ran out about 500 meters or so they were running on the fuel already in the the fuel lines & injection canister once that got used up the water came through.

Now that water wasn't there on trip prior nor do I have any leaks odd though when I filled up the front tank a couple of weeks back I haven't had a drop of water come out from that tank since easy to know if there was cause it would've shown in the seperators & that tank was bone dry prior to filling.

Best I can figure out is the theory that fuel expands push's out the air in the tank then the fresh air which re enters carrie's new moisture.

Dont think visiting scientific forums would be of any help as those guys wouldn't have had the benifit of knowing how wet or how my rig is set up & they could only make an educated guess.

No different to if you visit say a doctor with a ailment he'll schedule tests for the following week by which time the symptoms have disappeared & unless the right tests are done you'll get told there's nothing wrong with you

[Jumpus GooDarus]

Well I finally remembered to bleed the internal fuel canisters on the motors 2day last trip out a couple of weeks back the starboard motor was running sick coughing & farting & would cut out @ idle a reeal piss off when you're lining up the boat to drive up onto the trailer.

Actually bled out quite a bit of fuel just to make certain didn't really want to pull out the injectors & must say there must've been a bit of water in one ofhe canisters cn approx 00 ml came out B4 the motor stopped coughing & farting settled down to a nice smooth rythme.

Pumped a little extra fuel out of the tanks as well just to check & it was clean no water ! which led me to believe I made the correct call inicially condensation & maybe a bit of bad fuel from the servo

[SUMOFISHIN]

Have you considered this:: Heavy rain generally comes after heat, IF that is the case, then the fuel tanks in the bottom of the boat will cool after the boats exterior cools, thats when the rain is heaviest, why wouldn't contraction of the fuel tank SUCK water in the breather.

[Fed]

Pumped a little extra fuel out of the tanks as well just to check & it was clean no water ! which led me to believe I made the correct call inicially condensation & maybe a bit of bad fuel from the servo

So the condensation has just stopped happening by itself?
Well isn't that weird, could global warming have changed our climate that much?
HaHaHaHaHa!

[Jumpus GooDarus]

SUMO it's what I tryed to explain to Fed whom I might add didn't want to hear a bar of it

When this prob occured on my boat you have to remember I had not taken it out for @ least a month prior & the front tank was dead empty know this for a fact cause I had to swap over to the rear tank.

Which in all fairness plays on the point of expanding fuel getting pushed down the breather line in my case something around 3 meters & when it receeds new humidified air gets sucked back down the line.

The front tank being empty had no such probs but the front tank being @ least 2/3rd's full did add to that some very interesting info I found out a couple of weeks ago when I went out & bought some new fuel & breather hose for my little boat which cost me aroung $150 for 5 meters of 5/16 fuel line hose & 4 meters of 1/2 hose.

The hose was over twice the price of the stuff I've got in my big boat it's got a far better UV rating not to mention more importantantly it's interior contruction dont know if the guy was talking out of his :drop the daks: or not but claims were made the new stuff didnt attack water like the stuff in my big boat does completely different rubber.

Next time I take the floor up on the big goat I'll replace the lines on it just to rule them out see on the front tank 25mm alluminium tube runs out all the way to the transom where it is welded into the transom plate & yet to have a water prob with that tank where as the rear tank is a recent addition & has hoses runing back & forth.

So the condensation has just stopped happening by itself?
Well isn't that weird, could global warming have changed our climate that much?


Fed initially told you we had something like 3 weeks of bad weather there was alot of humidity in the air I may not be 100% correct but I nut thing out by ellimination I just dont go by what other peeps say or choose to post on the net like your mate [size="6"][/size]I Pissed In You Tank David Pascoe[color="#FF0000"][/color] reckons he did

[Fed]

Strange how you only get condensation in one tank, what do you think about that?

[Jumpus GooDarus]

Weight ratio on boat Fed I always run the front tank dry 1st just habit I guess & all I can put it down to is with no fuel in there to expand & contract guess no fresh air enters either.

Did take the big boat out for a run yesterday & both motors were purring I must've gotten all the water out

[Fed]

by the way my breathers are 1" in dia

That's like driving around in a car without a fuel cap.
You only need a pinhole to relieve any pressure anything larger is only used to stop any physical blockage that may occur from salt build up or crap or insects etc.

[Jumpus GooDarus]

Well read back Fed I said my breather line is around 5 meters long

How quick would a pin hole opening block up with such a small orifice ????????????????

Not to mention pressure buildup in the tank

Everything is done for a reason in the small boat breather lines aren't such are big run so I used smaller dia

ps] In the big boat it may me 25 mm tube but it's got a 3 mm wall thickness so opening is 19 mm

[Fed]

I didn't say to use a pinhole, all I said was that's all that was needed to relieve the pressure, 5M or 50M it makes no difference.
Larger sizes are used to stop any physical blockages but there is no way you need to go to 1".
Does this tube slope downhill from the transome to the tank, if so then what stops rainwater running down it?

[Jumpus GooDarus]

Well you better look up my boats manufacturer Fed & have a go @ them cause breathers came with the boat & are welded in

I've build quite a few tanks over the years & have to agree with what they've done makes perfect sense to me esp with tanks below a sealed floor.

Breather line rises around 80 cm's tucks under the gunnel where its tacked into position then welded into the transom.

Even my fuel lines out of the tank were around 15 mm dia with a 5 mm wall thickness B4 I replaced the tank with the 2 new stainless ones

[Fed]

Just because they make boats doesn't mean they know what they are doing.
Is the breather welded where it passed through the floor, perhaps they used a 1" tube to make it easier to weld with the heavier wall thickness. I didn't say 1" was wrong other than the explosive potential and it doesn't need to be so big to function properly, you'd have to agree with that. I'd hate to light a match at the transom outlet on a hot day. :o
The fuel lines could have been oversized for the same reason I guess.
The whole thing's a bit awkward thinking about built in tanks below a welded sealed floor, how are you supposed to inspect this stuff? Interest eh?

[Jumpus GooDarus]

Just because they make boats doesn't mean they know what they are doing.

I totally agree Fed seen some shonky work & there's always the case employee's leave a Co to start their own brand without having a clue other than how to slap a boat together but in my case I think they built my tub well except there were no drain off holes along the ribs which resulted in corrosion within the hull that's why I rebuilt the boat last year.

Original fuel tank was bolted in & with all such type boats with sealed floors an inspection panel gets sealed into the floor allowing access & yes breather & fuel filler tubes are welded through the floor this is done so no water spills into hull, short hoses are then used to conect these to the tanks.

you'd have to agree with that. I'd hate to light a match at the transom outlet on a hot day.

Just as much if not more chance of an explosion with a smaller orifice it's no more dangerous if fact alot safer than having breather inside the boat where fumes can get trapped back inside the boat @ least the way my setup is fumes disipate into the air

The fuel lines could have been oversized for the same reason I guess.

Wouldn't have done it any othe way fed remember my hull is 5 mm plate & if you were to say weld 8 mm tube to it best you could hope for would be a 1.6 mm wall thickness dosen't make for a good weld even though it's only stitched & there a good chane you'll blow a hole cause you need to pump up the amps to melt the alloy

[Fed]

Just as much if not more chance of an explosion with a smaller orifice it's no more dangerous

Do you make this stuff up as you go?

[Jumpus GooDarus]

Just replying to your suggestions thats all & use my noggin in the process

If you've got a small escape route for pressure then there a bigger pressure buildup inside the tank isn't there ???????

A larger opening relieves pressure from the tank @ a quicker rate

[Fed]

If you've got a small escape route for pressure then there a bigger pressure buildup inside the tank isn't there ???????

Not relevant when you consider the slow speed of the pressure build up.

Have you ever modified any of this system from new?
What size is the breather at the tank, 25mm? (And is it the same as the one in the old tank)
Was there ever a fitting on the transom that covered the breather outlet or something?

This has gone way past condensation although it may be part of the cure.
Are the original manufacturers still in business, I'd be interested to see what they say about this, don't want to see the good ship Jumpy go BOOM!

[Spudly]

Maybe FED put the water in th tank!!!

See, I think Ive figured it out!!!

Brather size isnt so relevant I dont think, Some fuel tanks are actullty fitted with one way valves that allow expansion but no suction, Ie i think i reffered to diffs in an early post (stop them sucking in water when they are rapidly coold when doing a river crossing) (this can place axle seals at risk of popping out of position so extended breathrs are a better option)

However moto X bikes also run a one way valve.

[Fed]

It's easy to imagine a hot diff sucking in some water when it cools quickly, they say trailer wheel bearings are prone to the same thing.
I believe it.

[Jumpus GooDarus]

Here's food for thought for you Fed !

Another advantage of having a large breather is ??

I refered to pressure buildup inside the tank well pressure can also build up when filling tank as well & nothing worse than those silly fuel pumps cutting out on you because the fuel has come up the filler line.

I get no such probs because my breathers get rid of pressure buildup in the tank very nicely & i know went tank is full when a bit of fuel comes out the breather, no spilt fuel enters my boat

[Fed]

Yep an extremely valid point especially with those rubber things they use on the pump necks now.
I just don't feel comfortable thinking about a 19mm vent pipe without a flame arrester fitted.

[Jumpus GooDarus]

Well when you finally get to see the Boat you'll see for yourself & eill agree it's a very good set up

Think it's a bit hard trying to explain things I have this saying that I think is quite good

Show Me, Dont Tell Me


Not everybody thinks the same or can picture things the way they are explained

Cant recall but think on my old big moored boat the breathers were quite large on it as well bear in mind I had 2 off 1000 litre tanks on it & the fuel was diesel no petrol

[Fed]

Go and Google "flame arrester" mate.
Unless there's something you haven't told me then you're sitting on a bomb.