2

Silver soldered storage box

SCHOOL OF MAKING

size as this will be slightly larger than your original

sketched rectangle. Allow 0.1 mm clearance so

that the box does not wedge in place, and don’t

forget to allow for the tabs which are folded on the

inside of the lid. Model the box and create another

flat pattern. You’ll now be able to determine how

large a sheet of metal will be required. We picked

a 1000 mm × 500 mm sheet and then adjusted the

design to use the full width of the sheet, this saved

quite a bit of sawing.

Simple gas torches consist of a brass nozzle and

regulator that screw into a fitting on the top of a

disposable canister. Bigger torches have pipes so

they can be used with large, and hence less portable,

canisters. The canisters contain liquefied gas which

boils as soon as it is released into the air. Some torches

have a sparker built in to light the gas, it’s also possible

to purchase a flint cup sparker to light the gas.

The regulators and nozzles are designed to work

with specific gases so if you want to use more than one

gas you’ll need to get the right burners.

Gas should be stored somewhere that is

well ventilated but also protected from the

weather. For larger bottles, a cage with a roof is

typically recommended.

There are several gases that are available in

DIY stores:

Butane Gas is the same gas you find in lighters. It’s

cheap and readily available. It has the lowest boiling

point of all of the options and hence, when working

in cold weather, this gas may refuse to leave

its container.

Propane is the next up the scale and is typically

found in larger burners such as the type for melting

roofing felt or killing weeds. The canisters for

propane are typically larger and, combined with a

bigger burner, can provide more heat. We found this

was the best option for the size of box being made.

Butane Propane Mix is cheaper than propane

and is a combination of both the above. It shares the

properties with both, providing more heat than pure

butane but is available in smaller canisters.

It’s worth briefly mentioning oxyacetylene, it is

possible to silver solder with this but you are more

likely to melt your metal. Oxyacetylene is great for

welding but might be tricky to adjust down to a good

temperature for silver soldering.

DIFFERENT TYPES OF

GAS TORCH

Above

Create dimensioned drawings to aid marking out

Below

Avoid frustration by getting your tools ready before you start

You can also use

cardboard to

prototype your box

if you are not so

familiar with CAD

QUICK TIP