Tuesday, January 26, 2016

Self Igniting Propane Torch Repair

Recently I decided to build a fire in my good old-fashioned wood fireplace, and like any well prepared Boy Scout, I planned to light it up the easy way, with my propane torch.  I screwed on the propane bottle and before I even had it tightened, I heard the sound of propane leaking.  My first thought was that the valve was not closed, but I tried to give it a quick clockwise turn and it did not move.  The valve was closed tight.  I realized the sound was actually coming from the inside of the torch handle, so I quickly removed the propane bottle.

When I disassembled the handle to diagnose the problem and make a repair, I also found that the wire clip that connects the ignitor button to the valve body clips on very loosely, and because of this, if the button were pressed, a spark could have occurred inside the handle where the propane was leaking, and the torch could possibly have exploded in my hand.  Any combustible gas has a certain ratio of air to gas to be able to ignite, and too far outside that range and the gas won't burn.  I don't know how wide that range is with propane, and therefore how likely ignition of the propane inside the handle would be, but the chances are greater than zero.

But, back on the failure.  I disassembled the torch and found the tube that connects the bottle fitting to the valve was no longer properly attached to the bottle fitting.   In the video I show this failure, provide a quick discussion on how the torch works, and I perform a repair and demonstrate that the torch is working again.

I do not know when this failure occurred.  The torch worked fine last time I used it.  Therefore, for safety reasons, I do not recommend leaving a propane bottle attached to a torch when it is not in use and being monitored by someone qualified to assure that it is working properly.  And do not press the ignitor button on a torch if you have any reason to believe it could be leaking propane or is not otherwise in perfect working order.