Gas Tank, Laz Ventilation and a floor for an S....

[Sumner]

I finished putting in a ....



http://purplesagetradingpost.com/sumner ... de-35.html

...... gas tank the other day and plumbed it......

http://purplesagetradingpost.com/sumner ... de-36.html

........ and....



http://purplesagetradingpost.com/sumner ... de-37.html

.... installed Lazarette ventilation and .....



http://purplesagetradingpost.com/sumner ... de-38.html

.... a floor.

The links to the mods are under the pictures if interested,

c ya,

Sum

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[kmclemore]

I guess I'm a little concerned that the inlet and exhaust for your tank area vent are so close together... seems like you'd just back-feed the fumes. With my on-board tank, the intake is at the helm, and the exhaust is near the transom. Plus, my 'tank enclosure' box' is entirely sealed from the inside of the boat... not sure if yours is?

[Russ]

Fantastic job. Wow, you can work with wood as well as metal.
That little filter cover Ruth made is a nice touch. All of it is very professional looking and practical. Kudos.


--Russ

[Sumner]

I guess I'm a little concerned that the inlet and exhaust for your tank area vent are so close together... seems like you'd just back-feed the fumes. With my on-board tank, the intake is at the helm, and the exhaust is near the transom. Plus, my 'tank enclosure' box' is entirely sealed from the inside of the boat... not sure if yours is?

Not sure I understand the question. The inlet for the ventilation on the Laz is on the port side of the boat and the outlet is on the starboard side of the boat.

On the S and D the laz are not sealed off from the cabin area entirely and thus the regs get a little confusing when using a 'vented' gas tank in the laz that is vented outside of the compartment. When we got the boat the previous owner (and I know others do this) had the stock outboard tank down in the laz. With it you have to have the vent open, so now it is venting into the laz. I didn't like that and we always had it up in the cockpit. We did carry sealed gas containers in the laz that didn't leak, but I still didn't like that either. I think this tank that is vented to the outside is much safer and if we ever do smell gas we can run the blower.

Russ thanks, but I kind of scabbed this together in a hurry and might re-do it at some point.

c ya,

Sum

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[Russ]

On the S and D the laz are not sealed off from the cabin area entirely and thus the regs get a little confusing when using a 'vented' gas tank in the laz that is vented outside of the compartment. I think this tank that is vented to the outside is much safer and if we ever do smell gas we can run the blower.

I've never been onboard an S so I don't know how the laz compartment is configured. With gas fumes being lighter than air, I would think you want the intake vent to be at a low point in the boat. That's where the fumes are going to collect. Down in the bilge area. That's where you would want to vent to pull FROM. The picture appears to be doing that but I can't tell how low your vent is in the boat.

My powerboat had 2 vents on port and starboard sides as yours. One had vents facing forward (to scoop air in) and one facing aft (to vent it out) as the boat moved forward. The blower intake was low in the bilge.

--Russ

[Sumner]

... The picture appears to be doing that but I can't tell how low your vent is in the boat...--Russ

The laz is 3 feet deep and the regs say it should be in the lower 1/3 of the compartment that is being vented. It is in the lower foot probably with the bottom of it being maybe 4 inches higher than the lowest point.

I figured that the advantage of the tank over using a normal outboard tank in the laz is that there should be no fumes in the first place since the tank is vented itself outside of the compartment and your plumbing should be leak proof. Of course that is maybe in a perfect world. If we were to smell gas then the blower goes on.

I have no electrical devices in the Laz except for one and that is the 55 amp breaker that has never tripped. There always could be the chance that fumes build and the breaker trips and bad things happen. Like you said the fumes settle and the breaker....



...is at the very top of the compartment. Having the blower/ventilation takes care of having the breaker in there as far as I can tell, but I might move it out of there at some point even though I think the chances of it causing a fire/explosion are very slim. The other problem trying to figure the regs out is that the laz is not completely sealed off from the cabin area and the cabin area (way forward of the laz) does have devices that are not spark/fire proof.

Is where the gas is stored on an X and M completely sealed off from the rest of the boat and are there any electrical devices in that area?

c ya,

Sum

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[Russ]

Sum,
The X/M have "portable" gas containers in the cockpit under the seats and they are VERY MUCH sealed from the cabin. Essentially they are part of the cockpit and no air can get into the cabin from their compartments.

The whole idea of blowers and venting is to remove gas fumes. If your laz is not sealed, fumes will go to the lowest part of the boat. That is where you want to vent from IMO. Even a small slow fume leak will put fumes in the bilge. A massive leak you will notice immediately. A small leak of fumes down into the bilge is what you want to vent out.
If your laz will suck air from the bilge, your setup looks fine to me. If there is some separation between the laz and air/fumes can't get be drawn into the laz, you may want to move that vent lower into the boat.

Most switches, etc, are not sealed. So the idea is to "blow" the bilge regularly. The most obvious times are during fueling when fumes will make their way down there. But honestly, anytime I get on the boat and before I'd turn as switch, first thing I would do is sniff for fumes. If any exist, blower goes on. Also before doing stuff that makes sparks down below, I would run the blower just in case.

For the most part, boats don't blow up often. Decent ventilation will take care of most fumes. However, use your nose.

Actually, you have made your boat MUCH safer by installing that tank. The previous setup was more apt to vent fumes below.

--Russ

[Sumner]

.............Actually, you have made your boat MUCH safer by installing that tank. The previous setup was more apt to vent fumes below....--Russ

Thanks, and yes I think it is much safer now also. On the S there is no bilge like is common on a lot of boats, except for under the seats and floor up in the cabin area. The Laz on the S is just a compartment that is sealed on the bottom from the rest of the boat and fumes would have to get as high as ....



....the hole in the picture where the cockpit drain comes into the laz. That hole and at the top on both sides are where fumes could find their way into the cabin area of the boat. So the fumes would have to raise way above the inlet for the blower to get that high.

I feel good about the setup and feel it meets regulations and it is nice to get ....



... the tank out of the cockpit and the other gas containers out of the laz itself,

Sum

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[grady]

As usual looks great. 19 gallons have you figured out how far you can motor with that much fuel? I have always wanted to figure out the MPG on the S model.

I have trouble burning up 5 gallons in a year motoring in and out of the boat ramp.

[Sumner]

..19 gallons have you figured out how far you can motor with that much fuel? I have always wanted to figure out the MPG on the S model. ..I have trouble burning up 5 gallons in a year motoring in and out of the boat ramp.

In our 40-50 days out last year we didn't burn 5 gallons either. It seems that most of the guys that comment on mpg with an S quote 10-12 mpg. Walt has motored a lot on Lake Powell and I think that is what he figured with the same outboard that we had last year. I'd agree with that although I have no accurate measurement. We used an older Honda 8 HP 4 cycle. We haven't been out with the new Tohatsu 9.8 HP yet, but hope to be soon.

I wanted to get rid of all of the gas cans and this way I'll have gas for the outboard, dinghy outboard and the gen-set in one convenient safer place. I don't see having it full except if we make the Erie Canal next summer and there you have 300-400 miles of motoring. If we get to do that trip I'll have a much better idea on the mpg. I might have it at least 1/2 full in Florida, just in case. On Lake Powell you can get 60 to 100 miles from a marina, civilization and it would be nice to have enough gas to motor back in an emergency. We almost did that on our trip, but hung in there a few days in one place and then sailed back. I'm hoping on the Erie Canal that we can get 150-180 miles on a tank.

I would of gone for a 14-16 gallon tank, but felt they actually took up more usable room in the laz vs. this one. I made a........



..... couple full size cardboard mock-ups, like the one above, and tried them. I made one for this tank also as it is long (which is the nice part as it isn't big in the other dimensions -- 47" X 10 1/4" X 10 1/4" ) and I wondered if I could get it down through the hatch and in there. Of course it went. I liked some of their tall thin saddle tanks....



....but they wouldn't go due to the drain from the cockpit. They were too tall.

I don't feel that the larger tank takes up any more usable space than the smaller ones and you always have the option on how much gas to put in it. After trips I'll siphon out what is left into the tow vehicle.

c ya,

Sum

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[Highlander]

Hi Sum,
Been looking at your Mods lately Man you've been busy your worse than me "Mod Hound"
Anyway thats some nice Mods your doing making your own Traveller & all nice work !

I think what Kevin was meaning regarding the fuel tank vent is that it & your fuel line outlet hole were rather close together & would allow fumes to be drawn back into the laz, but if you siliconed in a rubber ring grommet that would keep the fuel line from chaffing on that wall then siliconed around the grommet & line then the whole opening would be sealed not allowing any back feed of fumes back into the laz !. the vent blower should suck out any fumes reaching down futher into the boat as it creatates a vacum
I made screens for my vents to prevent bee's & such from entering them
http://i844.photobucket.com/albums/ab1/ ... 010001.jpg

here is my vent from the head
http://i844.photobucket.com/albums/ab1/ ... 010010.jpg
Here's my intake
http://i844.photobucket.com/albums/ab1/ ... 010019.jpg

I installed a "Y" into my blower fan with closable vents so as the blower can draw from either one or both you could also do that I have more pic's if you'd like to see

Cheers J

[Sumner]

...I think what Kevin was meaning regarding the fuel tank vent is that it & your fuel line outlet hole were rather close together & would allow fumes to be drawn back into the laz, but if you siliconed in a rubber ring grommet that would keep the fuel line from chaffing on that wall then siliconed around the grommet & line then the whole opening would be sealed not allowing any back feed of fumes back into the laz !. ...

Ok, I see that and will follow your guys suggestion. Thanks, and I've been following all that your have been up to also ,

Sum

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