Gas in bilge

[LadyInBed]

Wrong on both counts.
Gases mix, but not instantly.
Otherwise, you'd find all the oxygen on the floor, because it's a bit heavier than the nitrogen in the air.
A few % of another gas won't affect your breathing unless it's either CO2 which your breathing reflex reacts to, or CO or some other gas that has an effect on the body.

Escaping gas will initially sink, because it is cold from expanding and boiling off the liquid butane or whatever.
Try carrying some gas around in an open top bucket, it won't be enough to light after a few minutes.

Thats what I like about this forum, if you get somthing wrong, an expert will come along and correct you.

 

[Boathook]

Open the hatches and windows and use an air circulator. PBO magazine is very good and normally spark free. As others have aid whilst LPG is heavier than air, the slightest draft will move and dilute it.

 

[lpdsn]

Does the absence of a follow up post from the OP indicate that this one didn't end well?

 

[pmagowan]

Does the absence of a follow up post from the OP indicate that this one didn't end well?

Lol

 

[drew silverwitch]

Does the absence of a follow up post from the OP indicate that this one didn't end well?

All is well have no fear
Opted for the open everything up and retire to the bar option
On return the alarm had stopped but just to be sure used 1 of the deck boards as a big fan to waft air about in the bilges.
I have only just purchased this boat so after new stern gland, fitting a bilge blower is next