crickleymal
New member
We were exploring an old mine in the Forest of Dean last night. We'd had a brief look at it last year and having got the owner's permission went to have another look. Someone is already digging a passage there which might connect to Sling Pit and they had encountered bad air down there
We had not got more than 25 metres in and no more than 3-5 metres down when one of our party questioned the air quality (not helped by the amount of sheep sh1t in the entrance chamber). So I asked him to try his lighter. It (a Zippo) refused to light. I could see the spark and smell the fuel but it didn't light. So we back tracked and it eventually lit right by the entrance. After that it lit every single time even in a breeze.
So my question is, what mixture of gas would prevent a Zippo lighting? I would have expected it to light down to about 15% O2 or thereabouts.
We had not got more than 25 metres in and no more than 3-5 metres down when one of our party questioned the air quality (not helped by the amount of sheep sh1t in the entrance chamber). So I asked him to try his lighter. It (a Zippo) refused to light. I could see the spark and smell the fuel but it didn't light. So we back tracked and it eventually lit right by the entrance. After that it lit every single time even in a breeze.
So my question is, what mixture of gas would prevent a Zippo lighting? I would have expected it to light down to about 15% O2 or thereabouts.