Meco Midget Torch flame fluctuations

Jewelry Discussion
1

I have a Meco midget but the flame fluctuates so much I use my Smith
all the time.

I would like to use my Meco again as I found them better for some
types of projects. And the first person I learned from used a Meco,
and he was trained by his father, an old world artisan from Mexico
city. He could do more than most could dream of doing, and he
never changed tips on his Meco once. Always had a big bushy flame ,
he adjusted by moving the torch’s distance from the work. He told
me he could change tips, and use to, but now he just controls it and
doesnt have to waste his time changing all the time. Really quite
amazing.

Anyway, Ive cleaned, repacked, and just about everything I could
think of, including having a welding company check it out. But the
flame still changes so much its really useless. Has anyone had this
problem? Is there a solution? Daniel

2 
    Has anyone had this problem?  Is there a solution?

It’s probably not your torch, but rather, your regulators. Check
them out. Many single stage regulators tend, especially at lower rate
flows and pressures, to vary quite a bit sometimes, especially when
they’re a bit older.

Peter

3

Daniel, I use a Meco midget and prefer it to other torches used
over my years in jewelry work. The only time I have experienced
flame fluctuations as you describe was with a faulty regulator for
either fuel gas or oxygen or perhaps when the torch tip was not
tight on the stem, allowing gas leaks at the tip base. I would
check the regulators for proper low pressures, just a few pounds.
If using natural gas, the fluctuations could be from the supply line
or rarely air in the hose. Generally air will clear out rather
quickly and a “gas only” test flame will stabilize. You can use
oxygen only with the tip in water to get an ideal of severe
fluctuations but I doubt such a test would be worthwhile in small
variations of gas pressure. I would have to say the problem is not
likely the torch. Still, check for leaks around the torch valves,
etc. The Meco has a wonderful track record as reliable and
efficient over years of usage.

One modification I use is a tip with a tube soldered into the end,
forming an extension of about 1 inch. This tip allows a more
versatile and more adjustable flame than the standard tip without
the tube extension. I generally drill out the tip to close to the
od of the tube then hard solder the tube in place. This tip will
not stop the fluctuations you receive, since I would suppose
variances in pressure to cause that. The tip is quite workable for
most jewelry scale work without tip change.

Thomas.
@Sp.T

4 
I have a Meco midget but the flame fluctuates so much I use my
Smith all the time. I would like to use my Meco again as I found
them better  for some types of projects. ... Anyway,  I've cleaned,
repacked, and just about everything I could think of, including
having a welding company check it out. But the flame still changes
so much its really useless.  Has anyone had this problem?  Is there
a solution? Daniel "

Hi Daniel, Though I’m far from an expert at these things, having only
begun working with metals a few years ago, it sounds to me like
you’re experiencing the gaseous equivalent of the line-voltage
fluctuations that used to dim the bulbs at my old apartment. Since
you haven’t mentioned whether you’re using natural gas, propane or
acetylene, and haven’t said whether it’s coming from a tank or a
line (i.e. a gas main), I’m going to deduce that you’re using
natural gas, and that it’s coming to you from a city gas main. (I’m
arriving at this conclusion because, except in cases in which there
are kinks or other obstructions in the rubber hoses leading from
tanks, compressed gases in tanks tend to expel themselves in
relatively ordered, predictable fashions, while those coming from
shared gas mains are subject to other factors, including usage by
other customers, especially restaurants, laundromats and similar
high-volume users.) If I’m right in my assessment, there are only two
ways I can imagine to overcome your problems. The first is to make
sure that you’re using the right tips for your Meco torch. (They
have a set of vented-tip models, which resemble your Smith’s rosebud
tip, albeit much smaller, which are specifically designed for use
with natural gas, whereas the others are meant for propane, only.)
The second way would be to contact your local gas company and ask if
they offer a higher-volume line for commercial accounts, like yours.
I seem to remember that the plumber who came to assess my workshop’s
needs, last year, mentioned that natural gas is pressurized to
different levels in different locations, and that there were some
lines which were pressurized to 7-10 lbs/inch, and others, which
were only pressurized to about 2 lbs. In theory, if you were to
combine the wrong tip style, the lower pressure level and a relative
proximity to one or more variable volume users, you could easily
create a scenario in which your flame sizes would vary all across
the map. (I recall quite a few days like that, when I was in
school.) But change just one of those variables and I think you
should be able to improve things, if not remedy the situation,
entirely.

If you’re using the torch with a canned gas, could it be that you’re
either running low or dealing with a bad batch of gas? (While
filling in at a friend’s store, last year, I had similar experiences
using his Little Torch and a 14 oz. can of propane.) If that’s the
case, perhaps a different can’ll fix the problem? Again, I don’t
know enough to even speculate on this variation, but hope that
something I’ve said will prove helpful.

All my best,
Douglas Turet, GJ
Another Bright Idea! / Turet Design
P.O. Box 162
Arlington, MA 02476
Tel. (617) 325-5328
eFax (928) 222-0815
anotherbrightidea@hotmail.com

5

Thomas - Tell a bit more about the tube soldered into the end of the
tip for the Meco midget - what size tube (OD) length of tube (beyond
end of tip) and soldered into what size tip?? Sounds very
interesting. Sheridan