Getting a bushy flame with the Little Torch

I just checked the Archives and found some useful on this
question. Most of the posts suggested that the Little Torch is a poor
choice for working on Silver because it is difficult to get that nice
large flame. (Now they tell me!) However I wonder if adjusting the
regulators differentially would help to change the nature of the
flame. The setting up instructions recommend setting both regulators
at 5. Is it safe and would it be helpful to set the Oxygen higher,
and the the acetylene somewhat lower, or some other arrangement.
Someone mentioned using a 6 or 7 tip–would that help? I would
appreciate any

Thanks
Sandra Buchholz
Elegant Insects Jewelry

Sandra,

The setting up instructions recommend setting both regulators at 5.
Is it safe and would it be helpful to set the Oxygen higher, and
the the acetylene somewhat lower, or some other arrangement.
Someone mentioned using a 6 or 7 tip--would that help? I would
appreciate any 

The little torch’s limitations are due simply to the small size of
the tips. Those only form a narrow gas stream, and only allow a
certain limited amount of gas to flow, thus smaller sized flames. The
largest tip possible will give larger flame sizes, but even then,
it’s a rather small but hot flame with oxy/acetylene. You can work
silver with it on a smaller scale, of course, but you simply can’t
get a big soft brushy flame that will envelope larger areas of metal
unless you’ve got a torch that can both allow a higher gas flow
(usually needs larger diameter hoses, as well as bigger tips). Now,
you can increase gas flow to an extent by increasing the regulator
pressures (both fuel and oxygen). But do that more than a little, and
what happens is simply then the flames blow out.

Note that you can, in addition to using the commercially made tips,
modify existing tips to increase the size of the orifice up to the
size of the main tubing bore. Simply cut off the end of a small tip
(such as the almost useless #1 tip, too small for most jewelry use
(though not all. If you work very delicate wires, it’s useful. Also
good for polishing waxes…) Removing that ruby ended tip leaves you
with a larger bore tip. Or just drill out the bore on a larger tip to
the same inside diameter as the tube near it’s base. Tips modified
like that give larger flames. But they also can tend to burn back
sometimes (the flame popping and burning back into the tip or torch
body briefly. Not a major problem, but can be a surprise… That
happens mostly when lighting or turning off the torch. Also, the
multi orifice rosebud tip might be useful as well for larger areas.

Peter

Sandra - I have always used the little torch to solder silver. It is
a nice tool and well made. I do use oxygen and propane however and
prefer it. It burns cleaner in my studio with no black smoke. I set
the regulators at 5. I usually use a #4 tip. For a large piece such
as a belt buckle I use little torches multiple holed tip which
provides a huge flame and a lot of heat. Everyone does things a
little differently and they all work. The propane tank I use is from
a gas grill. You might already have one. I know the torch is specific
is the gas you use but it is probably exchangable.

Setting the oxygen regulator higher will allow you to do pretty much
any job with the little torch. The #7 tip is the largest and will
handle larger items quite easily. There is also a rosebud style tip
which is often used for annealing and heating very large items. This
is a large tip and heats larger areas effectively. For general
jewelry work, the little torch will work very nicely. It is light
weight in the hand and comfortable to use for extended periods of
time. The little torch does not have as large of a tip as the
acetylene air style torch could have with its largest tip, but
should be more than adequate for most any job that you can through
at it. Almost any torch should be able to do the job if used
properly. I have used the Hoke torch, acetylene air style and even
the Meko midget. I still prefer the Little Torch. It is what you get
used to or learn on. Old habits are hard to change.

I have used this type torch for over 30 years and there very little
it can’t handle. I have even cast smaller amounts of metal with it.
I have made large cuff bracelets to belt buckles, platinum to
silver. This torch will perform very well if used properly.

This is just my humble opinion after 36 years on the bench.

Best regards,

Phillip Scott G.G.
Technical Support
Rio Grande
1-800-545-6566

I don’t really understand the love affair with the little torch for
larger copper, brass or silver objects. These materials all have
high thermal conductivity and you need to heat the base material to
the melting point of the filler metal. If you don’t do this you will
get oxide problems which show up as incompleataly fused joints. This
is why you want a gentle bushy reducing cooler flame for these
materials. If the workis quite small you can get away with a hotter
flame that uses oxygen. With a little torch you would want a larger
tip and a reducing flame that is oxygen short ( higher fuel pressure
than oxygen pressure). On larger work a multiple orifice ( rosebud)
tip is useful. With some fuel- air torches you may want to restrict
the air inlet. I have sen this done in European practice, but never
in US practice. Conversely on a base material that has a low thermal
conductivity such as stainless steel you want to complete the joint
quickly heating with only local high temperature. In this case a
small tip with oxy-fuel works best. You still want a neutral or
reducing flame with no excess oxygen.

A slight reducing feather is best since most people can’t set an
ideal neutral flame. With stainless steel most people will overheat
the work an take the filler metal and oxidize the base metal which
then won’t take the filler metal. You have to work fast and you
don’t want to over heat the base metal. If the filler doesn’t flow
right, you have to clean and start over.

Never depend on flux to clean the work ! It is only there to protect
the joint area.

jesse

Setting the oxygen regulator higher will allow you to do pretty
much any job with the little torch. 

For safety reasons you should avoid setting one gas regulator higher
than the other. The reason for this is that if the tip should become
obstructed for any reason with the valves open you will force one gas
back down into the other gas line and an explosion can result. Yes
on certain industrial torches (cutting torches being a prime
example) often oxy pressure is set much higher but they have check
valves in the torch and or hose end to prevent back flow.

But for torches like we normally use there is no check valve in the
handle and they should be run at the same pressure.

James Binnion
James Binnion Metal Arts