How to mount a s/s fuel tank between the dual batteries

[Jimmy James]

Just wondering what is the best practice for setting up my stainless fuel tank between the dual batteries?

Should it be mounted on any rubber strips or anything for vibration or static?

Should I be concerned about sparks from the batteries so close to fuel vapours etc?

The batteries will be stored in the black plastic boxes104917

[Darren J]

Hi Jimmy,
That looks like the back end of a Seafarer Viking 5.2 (I assume). I had one of these with a 150L underfloor tank the full length of the floor. Are you moving the tank from the underfloor to sit cross the rear between the batteries, or is this a new tank, in addition to underfloor further forward?

The reason I ask is I know the boat I had would ride much better if you kept the weight out of the bum. It did have a 140HP Johnson 2 stroke on the back (max HP), so was prone to being bum heavy but I would think at a guess that your tank would be about 100 litres and would be a lot of weight in the back if there was nothing else to distribute the load. I had carried two 25L plastic jerrys in the rear in that area, from time to time and can tell you that including the main tank full, is a fair load. I had done tho with a 125 L esky on board also and had to drag that as far forward as possible, which still didn't really balance the load enough. I never did anything special with the extra fuel jerrys due to proximity to the batteries, but was diligent in ensuring they were in good condition as I was paranoid about a minor leak (or vapour leak) if they were under pressure and the proximity to the batteries and battery switch on the inside rear under the transom close by.

The main tank was alloy, it sat on thin treated timber battens to keep it supported/isolated off the floor. I guess this probably resisted against damage from vibration/rubbing and kept it out of any moisture that may have gone through there (front foot well drain lets water through under the tank area and out to the back). I don't think this was giving any resistance against static, but more so protecting the tank material itself from the surfaces it was in contact with. This install was original and over 20 years old when I sold the boat last year, with no problems.

For me refuelling etc at the rear between the tanks would be an increased risk in proximity to batteries, as you can guarantee exposed fuel/vapour fairly regularly close to the batteries. I suppose to be safe you could switch the everything off. The jerry's I had only ever travelled there. Having said that, my fuel primer bulb and clines/connection were very close to the batteries and switch...

Only real issue with my setup was breather at the rear meant full tanks would siphon out from expansion on the trailer, so needed to keep the filler cracked open as a breather at the front top of the tank.

PM me if you want and I can show you details or photos of how that was set up underfloor on my boat. I really think you may regret all that weight on the bum, particularly if your in the heavier range for motor size.


Cheers,
Darren

[Jimmy James]

Thanks for that insight Darren, a lot of food for thought. I have a viking 5.5 (1989) so may be slightly different to what you had.
This fuel tank does not fit in either of the underfloor compartments, But I believe it is original so maybe was never designed to go there?
The only option will be to position between the batteries.
104918

I am going to do a re-wire around the battery area to tidy things up so Ill probably do something to stop the vapour getting around them.

My breather pipe drains into the rear basin so I will have to be aware overflow when filling and travelling

[LittleSkipper]

Thanks for that insight Darren, a lot of food for thought. I have a viking 5.5 (1989) so may be slightly different to what you had.
This fuel tank does not fit in either of the underfloor compartments, But I believe it is original so maybe was never designed to go there?
The only option will be to position between the batteries.
104918

I am going to do a re-wire around the battery area to tidy things up so Ill probably do something to stop the vapour getting around them.

My breather pipe drains into the rear basin so I will have to be aware overflow when filling and travelling

Have you thought of fitting a plastic fuel tank? Check out Sant Marine on the web? I'm sure they would have one to fit and suit? Also a lot lighter than a stainless tank.


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[scottar]

I know it would be more money but if the tank doesn't fit I would flog it off and get one that does even if a custom one is required. Definately agree with Little Skipper about the weight distribution issue.

[Darren J]

Thanks for that insight Darren, a lot of food for thought. I have a viking 5.5 (1989) so may be slightly different to what you had.
This fuel tank does not fit in either of the underfloor compartments, But I believe it is original so maybe was never designed to go there?
The only option will be to position between the batteries.

My breather pipe drains into the rear basin so I will have to be aware overflow when filling and travelling

The boat I had was a 91, the rear appears identical to yours. It had a fabricated alloy tank (from factory I am pretty sure unless fitted out new by the dealer), but different to the one you have. It was full length however my boat did not have the central brace dividing the floor compartment in two.

Fuel tank breather was connected to a fitting which went through the rear engine well (up high). It meant if any fuel was pushed out (only during storage) it drained out of the engine well and never into the boat. My rear bilge area had a bilge pump fitted with timber batten platform over to create a level are dropped down between the batteries. It worked well. I will try and upload a few pics.

[fishwpa]

If height and width ok could you not just get that tank shortened to fit?

[Darren J]

104922104923

[Jimmy James]

You are probably right fishwpa...i have a few mates would be able to do it for me anyway!

So everyone is dead against the tanks at the back between batteries?? Just to confirm;

Is it mainly due to the weight distribution or is there a safety risk with proximity to the batteries?

This would determine wether it is best practice to move it or a definite change i need to do..

Thanks again for the help


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[Darren J]

I think weight distribution is the main issue. away from the batteries is just a bonus. At the rear may be ok if you had smaller tank and fuel quantity. I have seen V seas and the smaller vikings with 25 litre plastic tank only tucked in the rear. In that instance no issue, but when your looking to take max fuel capacity on you don't want to be dumping 100+ litres all at the back, at least I don't think so based on how the Viking 17 responded.
Hope this helps!.

Cheers

[Noelm]

It was common for those old Vikings to have a "cruise tank" in that position at the stern, that's what it was made for, can't remember the exact size that used to fit though, also don't remember any under floor tanks offered as an option back then either, most standard fuel tanks would not fit in the under floor storage setup, because the filler/pick up was too high and the lids wouldn't go back on flush.

[Chimo]

That tank does not look like an original tank. I too would resist locating it or any other tank in the bum. They dont like the weight back there. As others have suggested look into replacing your tank with one you can fit forward a midship. Most Seafarer SS tanks appear to have been filled and vented and supplied motors via the rear end to avoid loss of capacity due to pipes and caps on top.

[Fed]

It's a 5.2M, the 5.5M ones had a half pod.

I have a 5.2M (1986) so it's interesting to note the differences over year models & tank fitments.

FWIW mine has the underfloor tank and the rating plates Max @ 175HP.
There is no centre divider at all.
The coffin has a glassed in flat 'floor' (factory) which covers the keel.
Drainage from the little footwell runs under the fuel tank floor.

[Chimo]

Yes Fed's tank looks like my Seafarer tank with only the sender unit on top and the baffle welds obvious across the top / middle. The Vagabond bilge and tank support floor setup is similar with drainage under the fuel tank. Inlets and outlets for air and fuel at the stern end? Wasn't that standard Lindsay Fry for many years?

[Fed]

Yeah all my junk comes out the back too Chimo.

Notice Jimmy's has a beefed up floor where the seats mount, subtle differences over the years?

I'd expect the Jimmy's lower HP rating would be due to the rear mounted tank or they came to their senses in later years, 175HP would make mine dead set dangerous but a lot of fun.

[Darren J]

There is no centre divider at all.
The coffin has a glassed in flat 'floor' (factory) which covers the keel.
Drainage from the little footwell runs under the fuel tank floor.

Mine was pretty much identical to Fed's, tank construction as well and breather/outlet connections down low at the stern as Chimo says. My filler was a close to flush screw in alloy cap at the bow end on top, with a screw out deck fitting in the hatch directly above. pull out the deck fitting, then unscrew the alloy cap to fill. From dead empty I had squeezed exactly 150L into it. Only difference is mine filled the well size for size, to get it out would have required the removal of the angle's around the perimeter that carried the hatches.

The divider in the floor in Jimmy's, the higher HP rating, and the exposed vertical stringer in the keel all suggests to me his is not a 5.2, but probably a 5.5 as he suggests. I think Smithy knows a bit about the 5.5's from a mate that had one, if he is about?? I do not know about pods on 5.5's (whether they did or did not have them, but I thought the 5.5 version of the V nose front hulls were only built for a few years before the newer viking shapes were released in the early 1990's.

Either way n the 5.2 I had, there is no way I would be sticking all fuel on the bum. Too much weight down the rear tended to fuse proposing, mine also had a foil on it which I found helped with the weight issue, would also tend to cause cavitation particularly in a heavier following sea. Would sit on plane easier with the weight out of the bum.

[Noelm]

Back in the "old days" when I used to sell Seafarers, I fitted two with 175 Johnsons, and a few with twin 55 Johnsons, all had a "floor" in the storage compartment and no cross brace, almost all had a stainless tank in the rear that we fitted, did not come from the factory with any sort of tank fitted, even with a 175 the we're OK trim wise.

[Darren J]

Noelm, You might be able to shed some light. The Viking 17 (5.2m boat) that I think were talking about was made from about mid eighties to 91? was basically an extended version of the Vsea. Until the new hull shape came out around 92? Are you sure your referring to a Viking 17.
I know a few others that owned these and none of them were ever powered to 175. I have also never seen one for sale over the years with more than 140, in fact most seemed to have 90s or maybe 115's.

More than 140hp on the boat I had would have been very quick. It topped out right on 80km/h as I had it with old 140 s stroke, that included canopy, rocket launchers live bait tank etc and a little bit of gear for size of the boat. At 175 they would be very quick.

Jimmy seemed to think his boat was a 5.5m viking. Did they make this size in the V nose style up to the early nineties or do we think it is actually a Viking 17 (5.2) he has?

[Fed]

all had a "floor" in the storage compartment and no cross brace
So that would have been before 1989 Noel?
Jimmy's boat (1989) looks factory virginal with the cross brace & fibreglass floor support but without a floor in the storage compartment?

I'm thinking they made 2 boats, one for a underfloor built in tank & one for rear or even portable tank/s.

Interesting other comments about not putting weight in the rear, I intentionally added weight to the back of mine as I felt it rode better with it, started off with a I3 70hp but it took a V4 90hp to get it heavy enough.
That was after putting in a heavy storage seat/box filled with crap and a livebait tank.

[Darren J]

So that would have been before 1989 Noel?
I'm thinking they made 2 boats, one for a underfloor built in tank & one for rear or even portable tank/s.


Might make sense, mine definitely had no "floor" in the compartments. was open t the keel and allowed water to drain through under the tank.



Interesting other comments about not putting weight in the rear, I intentionally added weight to the back of mine as I felt it rode better with it, started off with a I3 70hp but it took a V4 90hp to get it heavy enough.


Mine had a 140 V4, I am not sure if they were a lot heavier than the 90's, but that may explain why mine was closer to bum heavy. Also had two larger Century Marine Pro batteries right in the rear, they were probably 25kg+ each.

[Noelm]

Yep, the ones I am referring to we're from around mid 80s and looked like an over sized VC... most were fitted with V4 OMC 90s, but we did one with a 70 that was next to useless, the ones with the twin 55s, (including my own) and two with 175s, they actually changed the mold a tiny bit to put a sort of cutout in the inner transom to allow for the bigger HP motors.

[Darren J]

They would have been quick with the 175's!. Would they have been a heavier motor than the 140 V4s?

[Noelm]

Yes, the 175 is heavier, both were for pro fishermen, and indeed they were fast, as long as you didn't get pounded to death by the rough ride, they could really get up and go!

[Noelm]

I will try and attach a copy of an old original Viking brochure, note the HP rating! no idea if this will work, because I have copied, cut and pasted and all sorts of things.

[Noelm]

woohoo, what a legend.....

[Fed]

That's a keeper thanks Noel.

Have you ever seen one with a self draining deck, I believe they made some?

[Noelm]

No, I have never seen one like that, we sold a lot of VCs with 70 Johnsons on them, and quite a few Vikings, I do remember selling a Vermont too, I had an old photo of a fishing spot that was popular when Kingfish were still easy to catch, and there was close to 20 VC and Vikings anchored at one time, I wish I could find it now, could be at home somewhere in all the other old photos that seem to hide in drawers and boxes. It was kind of funny selling them and Johnson motors back then, the only decision the buyer had to make was what colour the flash was on the side of the deck, options where pretty scant, the only thing I remember getting from new for customers was different seats to those silly fold up things, and the "reinforced" hand rail thing around the windscreen, which in effect was just a piece of flat alloy bolted to the screen frame, how things have changed hey?

[Noelm]

I just had a giggle to myself about a salesman we used to have, he could sell anything to anyone, if anyone's interested (and it is not derailing this thread) I will post his favourite sales pitch....to add extras to the sale.

[Chimo]

Yes please.

[Noelm]

OK, what he would do, as he was writing up the details, just as cool as you like, he would say something like "what colour do you want the canopy?" the buyer would look dumbfounded and say... "what canopy, I am not getting one" my mate would look astounded and state "you're buying a boat like this and not getting a custom canopy?" the poor customer would have to ask "how much" and my mate would give him a "super" price if he got it now, and not told the boss about the price he let it go for, next would be something like "would you like matching storm covers" again, the customer "storm covers?" and off he would go again, "what, paying for such a beautiful boat and it's going to sit out in the weather?" again the customer... "how much" and so it went.

[Chimo]

Trained at McDonald's, yes!

[Noelm]

haha, never thought of that, this was long before Maccas ever hit Aus... another funny thing he used to say if the buyer was getting a bit "cold" he would lean in close and say "just think what the neighbours will say when you take this home, they will be green with envy" that was sometimes just enough to get them into the office, so he could "sharpen his pencil" to get them the best price, as long as they didn't tell the boss of course.

[IcyDuck]

Nice one Noel. Love those colour choices ... burnt orange, blaze red, banana yellow 8-)