I’m having trouble with my hand-held propane and Mapp gas torches,
since I changed tanks.
My Mapp gas torch head was working fine (for the last 25 years)
until I recently put it on a new tank of Mapp gas – now it will
light when barely turned on, but then blow itself out, if I turn up
the pressure at all or tip the tank forward to use the flame for
soldering.
I bought a new propane torch head (Worthington Pinpoint model), put
it onto a new tank of propane, and tried to light it. It is hard to
light and won’t stay lit. I also tried it on an old tank of propane,
but it didn’t work there, either.
I have used propane and Mapp gas without difficulty for over 25
years – can anyone suggest what the problem is now?
[I have an old self-lighting propane torch head which is working (as
is my acetylene torch), but I don’t use it because its splayed-out
propane flame shape is wrong for my soldering.] I thought it might be
the Worthington brand of Mapp gas and of propane, so I bought a
different brand at Sears, but the problems remain.
TIA,
Judy Bjorkman
Using propane for your heating brazing work requires the use of a
proper pressure regulator fitted to the tank top.
This regulator reduces the propane pressure from around 90 psi in
the tank to what ever your torch is designed to use.
Most professional regulators have this pressure regulated between
off ie no pressure and say 50 psi, rated for the flow of propane in
cub ft a min at the designated pressure.
If you have used the same regulator for 25 yrs its internal pressure
reducing valve will most likely have deteriorated giving the fault
you describe.
Try another regulator. I would be very surprised if the torch or
tank are faulty.
sounds like you’re getting flashbacks- and like the new tank, if a
rental, may be bad (previous rentor damaged threads,?) Or the
diaphragm in the regulator blew if the pressure is high from the
lowest setting. Get it checked by a professional welding company
employee or friend that works with explosive gasses for a living -If
you haven’t figured it out on your own, time to exceed your grasp!
Its definitely nothing to play around with. The new tank sounds like
the root of the problem though. Another thing that’s not clear is,
are you referring to a set up with pre-set regulators like for
disposable tanks of gasses sold in home stores, if so they need
replacing. The seat was probably impressed in the o-ring and once
broken a crack, disintegration, etc.
could have happened. It’s simply too specualtive though- go to a pro
for assistance. rer