|
Gizmos by Category Geiger Counters & Atomic Stuff
|
|
Dusty Navigation
More Gizmos A - Z Philatector Watermark Detector Sinclair Micromatic Kit (Unbuilt) |
`
|
All information on this web site is provided as is without warranty of any kind. Neither dustygizmos.com nor its employees nor contributors are responsible for any loss, injury, or damage, direct or consequential, resulting from your choosing to use any of the information contained herein. Copyright (c) 2006 - 2020 dustygizmos.com |
Here’s one for Star Wars trivia fans; what is the connection
between R2D2 and 3-CPO and laughing gas? Several, probably, but the one we’re
interested in concerns the Microflame Model B gas blowtorch. Okay, that needs
some explanation
The first time we see it is in the hands of a Jawa, welding a
Restraining Bolt onto R2D2. Luke Skywalker later uses his Microflame to repair
3-CPO’s arm, and for some reason Han Solo has one the gas cylinders attached to
his belt. But what about laughing gas? Well, the Microflame has two gas
cylinders. One contains Butane, which makes the flame, the other one is filled
with ‘Micronox’, Microflame’s trade name for Nitrous Oxide. This is a powerful oxidizer, with similar characteristics to Oxygen, making the
flame even hotter. Nitrous Oxide or laughing gas is best known as an anaesthetic. It’s also
used in whipped cream makers, making souped up cars go faster and recently it achieved notoriety as
a popular recreational drug, which the tabloid press like to call ‘Hippy
Crack’.
The design is elegantly simple. The two cylinders are mounted in a
sturdy cast metal frame that acts as a handle. They are kept in place by
cup-shaped holders attached to a screw thread and a thumbwheel. Rotating the
thumbwheel pushes the cylinder up and into the valve block where a thin metal
tube punctures the seal in the neck of the cylinder, releasing the gas. The red
and green knobs control gas flow to the burner head at the end of the wand,
which can be fitted with a variety of attachments, for soldering or making
larger or smaller flames. In the US a small cottage industry grew up around the
Microflame with third party accessories and numerous books and magazine
articles showing how to use it and construction projects.
Microflame caught my eye back in the late 1960s, appearing in ads
in publications like the wonderful and much-missed Exchange & Mart. At the
time I was briefly interested in radio controlled model aircraft and for some
reason it seemed like something I might need (though flames and fabric-covered
balsa wood would not have been a happy combination…). It never happened; they
were prohibitively expensive at around £25, and my spectacularly unsuccessful
attempts to build and fly model aircraft dissuaded me from spending any more on
that doomed hobby. I had forgotten all about the Microflame until I came across
this one at a car boot sale a few years ago. This time I could afford the £1.00
asking price for what appeared to be an almost complete kit in apparently very
good condition in its original, though very tatty cardboard box. Not that I had
any particular use for it but it rekindled the urge to own one, and as I
reasoned, who knows, it might come in handy one day… 
It came with a couple of unused cylinders and after applying some
silicon spray to the rubber washers and gaskets to soften them up, decided to
give it a go. It worked really well, but not for long. The Butane gas cylinder
lasted about 10 minutes, which was probably due to leaky seals. Supposedly
they’re good for around 30 minutes burn time, but even that wouldn’t be much,
even for model engineering applications. It wouldn’t have been a huge problem
back in the day. According to the price label on the box that came with the kit
replacement cylinders cost 75 pence for two. That would have made it reasonably
affordable to use but the problem now is Microflame disappeared in the late
90s, along with a reliable supply of cylinders. Articles on the web suggest
that a UK company may still have stocks, or the facility to refill them, but at
a cost. There are alternatives, however. Nitrous Oxide cylinders for making
whipped cream (and brief ‘highs’) are readily available, and a couple of
websites suggest that the butane cylinder can be back-filled using a cigarette
lighter refill, either directly through the burner wand, or by drilling the
cylinder and fitting the refill valve from a discarded lighter. Both methods
appear quite risky so I won’t be trying them anytime soon.