2nd fuel tank setup

[Whamo]

Hi all, Was wondering if any1 can help me with a few questions?????/
First of all i have a 5.2 southwind which has a 80liter stainless tank in it already but would like more. there is no more room to just replace that 1 with a bigger 1 in the same hole so i have to put 1 in behind the console.....
1. is there any problems using a f/glass tank and stainless tank together?
2. what is the easiest/ best way to combine them both (1 feeding the other)
3. would it be better to just use different lines ( just swap the fuel lines over once the main tank was emptied
4. Is there some sort of electrical system that can switch from tank to tank ( like in a landcruiser with duel tanks )
5. when making a tank for marine use do they put baffles in them to stop fuel from sloping around

If anyone can help with these questions it would be great or even point my in the right direction . thanks in advance Whamo

[gone_fishing]

1fibreglass and stainlees cant se a prob but not 100%
2 joining the tanks together really depends on postion
(a) one tank feeding the 2nd ok as long as higher postion and 2nd tank dosnt have any openings lower than highest point of both tanks cause over flow
(b) seperate tanks probably better imo( bad fuel in one wont contanimate fuel in other tank) set up with a t piece and tap can run either or both tanks
3 imo use seperate fillers and lines to a t piece could run a seperate filter in each line if you want to
4 could run a small submerible pump in one tank to pump to the other another thing to go wrong make sure you still have a manaul operation (gravity works well with tap set up
5 baffles ? not sure but wouldnt be a bad idea in a good size tank
thats my 2 cents hope it helps

[Whamo]

yer I think i agree with ur thoughts on seperate tanks with a simple 3 way tap, i didnt think of this easy setup till i looked through a whitworths cat. ( i was thinking to technical to start with ) lol. The other reason i was thinkin of 1 feeding the other was cause in the southy i couldnt think of an easy way to get the filler to the gunnel, but that can be easly solved by putting the filler in the side of the center console :) thanks for ur thoughts.


1 other question though..... is there a different grade of glass that i would have to use or is it all the same????

[gone_fishing]

dont honestly know about fibreglass and how it is effected by petrol
i believe there is different grades depending on the material but i honestly dont know
i would although recommend some reaserch on how fuel effects f/glass may require a bladder
cheers

[Scalem]

Hi Whamo.

I run 2 tanks. Originally 60 litrs at the transom of my 4.3mtr boat was too much weight in the back, which caused porpoising I could not control with trim. Also the big flat stainless tank took up some of my valuable floor space, it was just too big for the boat. So this is what I did.

*** Sold the 60 ltr stainless and bought 3 x 25 ltr plastic tanks. I place two up under the bow, and one fits neatly close to the transom.

*** Bought a fuel filter - I think its a Racor, where the base has two inlets.
*** Fit an inline tap with the right thread into one of the two inlets, a normal inlet to attach fuel line on the other inlet.

So.... If I run the tank under the bow via the tap and longer fuel line connected to the filter, I disconnect the hose to the other tank under the transom. The normal fitting on the hose that connects to the fuel tank under the transom has a spring loaded ball bearing which seals when disconnected, which then causes the fuel to come from the other tank. ( provided you have opened the tap located at the fuel filter.)

If I want to draw fuel from the other tank located under the transom, I simply turn off the tap which supplies fuel from the tank located under the bow.

If you have no way of turning your main tank off, you must be able to put an in line tap into the fuel line somewhere, but the best place would be at the filter, which you should be running regardless.

One other thing I did was put a fuel primer bulb in both lines leading to both tanks.

So going back to basics ( because it might be confusing the way I have explained it)

1 fuel filter - two inlets to two tanks via normal fuel hoses.
One inlet has tap, other does not, but when disconnected, bearing seals it.

Easy??:D

Let me know if I can help further, and if this suits you.

Scalem

[mcgilld]

I run a 120 underfloor and a 75 in rear bilge for long trips in an 18 footer.
A line from each tank leads to a 3-way tap thence through filter/separator, breathers are joined and exit through topside as one.
I preferred to keep them separate: the rear tank is heavy at the stern so I use it first on long trips then switch to underfloor. When not travelling too far I use the underfloor only - so a good weight spread is achieved.
You can't have this option if you join them - unless you feed the underfloor from your additional tank rear of the console.
Make sense?
Hope it helps