Mouth blow torch-bottled gas problem

Hi

I use a mouth blown torch (for use with bottled gas) that I bought
in London a few years ago and has been just fine until today.

The torch has two metal tubes - one for oxygen from the mouth and
the other for the gas supply which is controlled by a knurled wheel
acting as a tap. 2cms above the wheel there is a whole which passes
horizontally through the tube. (I hope this is clear)

Today, whilst using the torch, I had a flare of flame from this
hole. I have used it since without any problems, but would really
appreciate any advice as to what caused the flare.

Very best wishes to everyone
Judy

Sounds like a clogged tip, You probably had a piece of dirt in it
that just fell out.

Any of the atmospheric air torches can exhibit this problem. Oxy-
fuel torches may flash back into the hoses. Clean the tips.

jesse

Hi Judy,

I use one of these all the time, you have just had the gas ignite
where it starts to mix with the air. It may be that it needs some
more grease around the conical seal. Just make sure that you don’t
block the tiny hole the gas goes through. If you can’t sort it out,
if it is an Adaptogas or Microflame torch ( basically the same ) you
can send it back to them(Microflame) for a service, about 30-35 I
think. I don’t know why more people don’t use them , they are so
controllable,

regards Tim Blades.

Hi Tim

Many thanks for your advice. I think it probably does need a clean
(the tips are a bit black), but I’m not sure how to do that. Is it
just a matter of getting something like an old toothbrush into the
tips?

I also really like using this torch - have become quite attached to
it. I never get firescale, I can work on very small areas and it
works for nearly all my fabrication needs.

Best wishes, Judy

Hi Judy,

but I'm not sure how to do that. Is it just a matter of getting
something like an old toothbrush into the tips? 

it is not the tips that are your problem it is the gas seal on the
handwheel that you turn. This has a tapered metal to metal fitting
and is very lightly greased to stop gas leaking out, in time the
grease wears away. It has one nut which if you take it off the largew
knurled knob will pull out sideways. It is a bit sensitive to put in
the right amount of grease and adjust the tightness, so that it is
easy to adjust with one hand. If you are unsure about doing it
yourself, get in touch with the Co. The tapered cone has a tiny hole
going through it that you must not block, it is just a very delicate
ga s tap, the tapered bit means that you can adjust how tight it is
to twist the knob, it should be comfrtable to do with the hand that
you hold the torch with, but not too easy.(I expect I am teaching my
grandmother to suck eggs!)

Here is the link to Flamefast (sorry, I got the name wrong before!)

http://www.flamefast.co.uk/heat-treatment/mouth-blown-torches.html

I don’t have any connection, I just had to track them down to get
one modified. I bought one in the mid 70’s and the company has changed
but they still make the torches, and bigger ones.

PS If you do get it serviced get them to change the pilot light
screw, once they get old they are the very devil to get out without
damage!!

regards Tim Blades.