Newport butane refill cans

[Jose Arcadio Buendia]

I bought a 250ml/139g Newport butane refill can. I measured with a syringe 9.5ml of butane for a ~3.2% mixture in my 290ml chamber combustion cannon (I measured the chamber volume using water and a syringe) and it did not fire. The cannon has a chamber fan so an equal mixture within the chamber is not an issue. I tried using a ~4.2% mixture (12ml) and it fire perfectly. I had previously used butane from a Ronsonol butane can and it works fine at ~3.2% (9.5ml). It seem very strange that the Newport butane will not fire at the expected ideal mixture of butane, but it will with a higher percentage. Has anyone here had this same issue or might know why this happens?

[jackssmirkingrevenge]

Sounds like it's either propane, or not as pure as they claim it to be.

[Jose Arcadio Buendia]

Sounds like it's either propane, or not as pure as they claim it to be.

Yes, it is propane. I searched for the MSDS of the Newport butane and it contains propane.
http://www.e-hygienesystems.com/coshh/s ... ml%202.pdf
I tried filling the syringe for 3.2% mixture with the can upside down and it worked well. I guess since propane has a much higher vapor pressure than butane when filling the syringe with the can upwards the majority of the gas that pressurizes the syringe is propane. I will wait for the propane to be purged out of the can through filling the syringe upwards since filling a small syringe with the can upside down is somewhat wasteful since a small amount of liquid butane is sprayed into the syringe that then evaporates, so its easy to overfill the syringe. The propane content in the can would matter if it was used for filling lighters, but it doesn't take much pressure to move the plunger of a syringe.

[jackssmirkingrevenge]

Propane is a slightly more energetic fuel anyway, it's not a bad thing