Fortunately, most bench torches can be easily adapted for
even the smallest soldering operation. If you want to control a
very tiny flame, but your torch tips do not go down small
enough
in size, try using an old hypodermic needle. These needles come
in a range of sizes, and they fit perfectly over many torches,
including the Meco Midget.
Here is what I learned to do while I was a student at TIJT.
1 Take off the tip on your Meco Midget and find some nuts which will
screw on in place of the tip. 1/4" fine nut I believe.
2 Get some all metal stainless Hypodermic needles as used by
veterinarians get differing gauge needles, but buy the longest
available.
3 Solder the needle to the nuts using only enough silver solder. The
internal threads can be protected from solder by using antiflux.
4 Cut off the tip to fit and save the cut portion. It can be used to
reduce the orifice size in older tips. I used a 4/0 saw blade and
filed the tip. Tip cleaners are great to clean out the inside of all
gas tips.
5 Get thee to a welding shop and purchase a set of tip cleaners. I
like the ones which open up and fold out with all the cleaners like
wires.
I am indebted to Mr. Revere for all of the effort he has put out as
well. I have his books and watch his video’s as refreshment and
inspiration.
1 Take off the tip on your Meco Midget and find some nuts which
will screw on in place of the tip. 1/4" fine nut I believe.
2 Get some all metal stainless Hypodermic needles as used by
veterinarians get differing gauge needles, but buy the longest
available.
That’s all very good advise - it’s also needlessly complicated - here
in Calif. you can’t buy needles without a prescription, for one. When
I used the Mecco (Swiss torch, now), I just bought a tip and soldered
fine brass tubing to the end, and then drilled it through…
Get some all metal stainless Hypodermic needles as used by
veterinarians get differing gauge needles, but buy the longest
available.
That's all very good advise - it's also needlessly complicated -
here in Calif. you can't buy needles without a prescription, for
one. When I used the Mecco (Swiss torch, now), I just bought a tip
and soldered fine brass tubing to the end, and then drilled it
through....
Instead of cutting hypodermic needles and having to debur the
result, you can order blunts or stubbies. They’re manufactured just
like hypo needles but have a smooth squared off end rather than the
beveled point needed for injections.
I use a water torch so I have to use needles. My best source is
Contenti. They have a wide variety of gages that they sell for use
with epoxy based enamel. The ends are squared off, so they are ready
to use. Here’s a link for anybody that can use them.
In my “other life” one of the things I became widely known for was
making microsurgical instruments out of needles, they’re really
quite easy to work on.
Hypo needles in general are made of hard drawn 304 stainless. After
"nicking" one with a fine file edge it can be easily broken in your
fingers and rather cleanly at that. The trick to trueing the end,
without burring, is slow speed. DON’T USE A GRINDER, FLEX SHAFT OR
OTHER MOTORIZED ABRASIVE–DO IT BY HAND. A 280 wet-or-dry sanding
stick works well and a few SLOW strokes will true the end with
minimal burring. Then, if you want to really tidy up the end, use
ordinary rouge on a 1/2 x 1/2 felt in your flex shaft at slow speed.
Bring the tube in at 90 degrees to the felt and ONLY TOUCH THE FUZZ
AT THE EDGE OF THE WHEEL TO THE METAL. This will polish the end while
rounding both the internal and external edges. When this is done very
gently the rouge doesn’t even plug the tube, but the wash-up is
facilitated by using a soap soluble rouge.
For many years (38) we have worked in tens of thousands of
applications in many industries and with customers who needed to
produce flames through hypodermic needles. We even have a special
division of our firm, which produces special flame head systems.
Under no circumstance should plastic hub hypodermic needles be used
for nozzles in any gas torches. It is unsafe practice on any torch,
including water welders, and this is clearly documented, even if some
manufacturers supply them with their units for cost saving reasons.
It is also an unsafe practice to just fit tips onto a tapered tube
for a torch. It is an unsafe practice to use a plastic hub tip in a
proper Luer fitting for a torch. It is not an uncommon event for
there to be an interruption of gas production, in piped, bottled or
generated gas systems. These factors cause a reduction of outgoing
gas pressure and for the gas in the tip retreat into hub and
detonate. We call this event a flashback, and it can propel the tip
at high velocity through the shop.
I have on several occasions seen a few of these plastic hubbed tips
imbedded in a ceiling or wall, and thought how lucky it did not find
an eye along the path of travel. There have also been examples of the
hub being deformed by heat and causing an unanticipated and larger
flame in a direction not wanted, burning the operator. Or fires
within the handpiece itself. There is also a difficulty in radiant
heat, reflection from your work softening the plastic hub of the tip
and creating the same unsafe event.
So, It is critically important only metal hubbed tips properly brazed
to the correct threaded nut as recommended by Alan Revere be used.
Or, as in our case, a complete metal male and female Luer fitting
connection which will retain the metal hubbed Luer tip even during
conditions of interrupted gas flow or a flashback. It must also be
noted in a detonation of gas at the tip, a plastic hubbed tip will
deform and easy come away from (launch) from a full Luer fitting.
This can leave one with a torch handle with no tip and an unexpected
very large flame, making a small problem into a much larger problem.
Our Spirflames[tm] generate a much smaller, and much larger flame
than other generators can use, but a dozen assorted metal hubbed
hypodermic needles, properly prepared with case only costs $60.00 per
dozen. These tips last many years with the minimum of care, so there
is no good reason to use unsafe plastic tips for torches in spite of
what may be supplied. Plastic hubbed tips are wonderful for use in
delivering solder paste, glues, gasketing materials, resins. Under no
circumstance should plastic hubbed hypodermic needles beused for
nozzles in any gas torches. If you wish additional documentation or
references, please feel free to contact me directly.
Best Regards,
Gary W. Miller
Sr. Technical Advisor www.spirig.com