console ventilation?

limeydal · 21 September 2004, 05:51

Just setting up the electrics in my XS-RIB with built in fuel tank in the console and wondered if I need worry about petrol fumes .
With all the switches and the possibility of it arcing,is there a danger if fumes are present that it might ignite?
I know in larger boats they recommend an inlet and exhaust air vent to ventilate the space and even blowers in some instances.
So do I rely on the fuel system being sealed well ,or do I need take other precautions.?
This is my first boat with built in tanks so want to get it right!
cheers Dal

Rogue Wave · 21 September 2004, 06:27

The MCA (coastguard coding ) pver here specs that a hydrocarbon detecter be installed in the bilge of a rib, although this is only for commercial purposes.

It was always my belief that the inbuilt tanks had an overflow filterwhich also acts as a vent., If i say any more than this then I'll be talking out of my chuff ( not fo the first time I suspect)

happy trails

swginn · 21 September 2004, 11:09

I also was a bit worried about this. Your tank is vented to the outside of the console using the overflow filter/vent that Rogue mentioned. I have over filled my tank before at the petrol station only for it to come out the vent at the other side of the console. There was no sign/smell of any petrol inside the console afterwards. I have checked and do check regularly the connections from the fuel tank to the filler/vent. You can never be too careful around 110 litres of petrol, however the fittings are top notch and haven't been a problem so far.

chrisallse · 21 September 2004, 18:31

whilst i was rewiring my RIB I fitted a blower into the bilge to reduce the chance of fume build up.

limeydal · 23 September 2004, 05:58

Just returned from my Coastguard Aux; class where i asked the question about venting the console.
It seems if the fuel tank is permanent and is in a location where they may be an ignition source(eg electric switches or inboard engine) then it must have an inlet and exhaust air vent.
So leaves me with the problem of venting the console without compromising it waterproof properties.
Looked at some louvred vents but still wouldn't stop the water if i took a wave on.
So unless there is a special vent made for this,maybe putting a plastic elbow on a hose vent pointing up to allow air flow with a smaller drain tube below to get rid of any water that did leak in.
Not really going to be taking on the rough stuff over here, but dont want to risk getting any water in the console compartment.
Anyone have other ideas?
cheers Dal

Simon Hodder · 23 September 2004, 07:50

Definitely don't go down the louvred vents route! Our Humber 5.5 came with one on the console, and even towing it in the rain lets water in, right over the battery area, let alone salt water spray when the wind picks up.

Mark Halliday · 23 September 2004, 08:52

You need baffled vents. A chandlery should be able to sort you out.

Basicaly the air passes over a series of baffles in a serpentine route. The baffles "knock" the water out of the air.
You could make your own to go behind a louvre. The air must go up, then down and then up again. A small hole at the bottom of baffle will let collected water out.

Scary Des · 23 September 2004, 09:06

Hydrocarbon gas is heavier than air so any venting should take place at floor level, which is unfortunately where the water ends up after a big wave event.

I would vent at the rear of the console and look at the ‘cat flaps’ you get behind the rear bumper (fender) in a car. Some of these are extremely well designed with rubber one-way valves and drains. Des

Mark Halliday · 23 September 2004, 10:17

Interesting idea Des. Could be a lot cheaper than paying the "marine surcharge" you get on anything nautical.

Heater fresh air inlets are also very good at stopping water ingress, it may be worth a poke under a bonnet (hood) as well.
Also 2 vents may be an idea, so you get some sort of air flow. One high up and one low down perhaps.

ollyit · 23 September 2004, 10:32

I was thinkin about installing a silent 12v Computer CPU fan perhaps? - cheap reliable and more importantly cool when wired the correct way - hey you could even get a blue led lit up one!

got loads at work, free if u want any

Pete7 · 23 September 2004, 17:30

How about something like this ? screws out when filling and closes on an o ring seal when at sea.

Pete

limeydal · 30 September 2004, 06:07

Pete,
like that!!!
Whats it called and where did you get from?

I had to ventilate to get past coastguard inspection.
So put a round hose vent(exactly where your shows actually) with louvres on the front.
Then on the rigid hose coupler on the back I cemented a 90 degree elbow up and a 6" length of pipe with a couple of angled baffles set in it.
It wont stop a complete deck swamping but would fend off any splash or anything under about a foot of water in the boat.
But I do like yours if I were to go offshore.
cheers Dal