HackSpace_-_October_2019

FORGE

the top where the foil seal attaches. You’ll need to
use your can-opener to remove the lip from all of
your cans, and then remove the bottom of all of the
cans but one. The can with the base in will be used
as the bottom of your storage tube, and the other
cans will be brazed on top of this can.
Whenever you’re preparing to braze something,
it’s important to make sure that your joining surfaces
are clean, dry, and have any surface coatings
removed before you start trying to heat them up.
Use a wire brush or some abrasive wool to remove
any paint or other coatings from the inside and
outside of the can where they will be joined, and
remove any oil, dirt, and rust that you can see.

Stack one of the bottomless cans on top of the

can with the base still attached, and make sure that it

sits neatly in place. Most cans have a slightly

reduced base that allows them to be stacked on top

of each other easily but, if your cans don’t hold firmly

in place, you can use a magnet to keep them steady

while you’re working. Just make sure that the

magnet is positioned well away from the heat source,

as too much heat will ruin it.

Now you have one can stacked on top of the other,

you can apply some flux and get ready to start

brazing. You have some choices about which type of

flux and brazing rod that you use. If you’re familiar

with soldering, you probably know that flux stops the

heat of the gas flame from oxidizing the metal you’re

trying to join, and that helps the filler metal you’re

using to flow nicely around the joint. If you want a

very smooth joint, you can paint all of the way around

the part that you are joining with a liquid flux, and use

a silver alloy brazing rod. The silver alloy flows very

easily and evenly into the heated joint by capillary

action. If you’re not worried about the joint looking

Above

It’s best to keep your brazing rods labelled, as different alloys

can look very similar to each other. Here, you can see silicone-

bronze (top), brass (middle), and 55% silver rods (bottom)

Above and right

Clean paint from the cans with a wire brush to get the best

joint, and remember to cut the bottom out of the can before

you braze it in place

YOU’LL NEED

Propane or

MAPP gas torch

Brazing rods

(silver or brass

is fine)

Brazing flux

(powder or liquid)

Steel coffee

cans (or similar)

Can-opener

Wire brush

or wheel

Needle-nosed

pliers

Spray paint

Personal

protective

equipment (safety

glasses, flame-

resistant clothing)

Working with anything hot carries certain dangers. The most obvious one is burning

yourself, so make sure you don’t touch hot metal. All smoke and fumes are bad for you

and some are more dangerous than others. Ensure that the place you’re working is well

ventilated and make sure that any smoke goes away from your face. Make sure that

you’re aware of any risks with the particular metals you’re joining. Avoid working with

anything containing zinc unless you have the appropriate skill and equipment.

BRAZING SAFETY

Certain types of

metal release toxic

and corrosive

fumes when

heated. Check

what’s safe,

wear appropriate

safety gear, and

work in a well-

ventilated area.

QUICK TIP

You’ll need to use your can-opener to remove the

lip from all of your cans, and then remove the

bottom of all of the cans but one

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