http://www.armortek.co.uk/Forum3b/viewt ... 7759937b15 (to be updated).
Another ADVANCED technique involves aluminium brazing, which is covered here:
http://www.armortek.co.uk/Forum3b/viewt ... 423ce26c97
How do I get the patterns? Start with a maquette (a "rough draft" or preliminary design). That will give you the patterns and the fit. Best is to scale down the original measurements but judging by eye can be effective. A maquette can be made from card or plasticard. The ultimate is to model the assembly in a 3-D drawing tool and transfer the design to flat patterns. It can be as simple or complex as you wish.
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Materials- use tinplate or brass. Good sizes are .025" (.635mm) for the base and .010" (.25mm) for the rest.
Bending, Cutting/Shearing, Rolling sheet. You can use a vice for bending and aviation shears for cutting:
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but better still, invest in a "formit", which combines all three, such as this one:
https://www.warco.co.uk/sheet-metal-fab ... chine.html
Work Holding.This is key and will govern whether the job is easy or hugely frustrating. One good system is to use a piece of sheet steel as a base and rare earth magnets to hold and support the work.
Spring clamps are also useful for the later stages
Soldering. This is likewise the source of head banging frustration or smooth operation. Cleaning joints is vital. I'd use a solvent cleaner first and then a fibreglass cleaning pen.
For the soldering, your biggest challenge is managing the heat. Silver solder (recommended) requires about 450deg C. That can be a challenge on a long seam. A butane soldering torch is a cheap option - such as the Dremel:
https://www.dremel.com/en_US/products/- ... tane-torch
You might also need direct flame:
https://www.proxxon.com/en/micromot/28146.php
The best (but expensive) option is resistance soldering, which is covered in a separate topic.
With the work held firmly and clean, a flux is applied, the joint heated to the melting point of the solder, which will then run into the joint by capillary action. It's important not to apply the heat directly to the solder, which should be allow to come to temperature by contact with the joint surfaces. Seams can be soldered by running solder along the joint. To join surfaces, sweating is the best technique, covered here:
http://www.armortek.co.uk/Forum3b/viewt ... ?f=6&t=529
For assemblies such as bins, it's best to solder from the inside but this isn't always possible and sweating can be used.
Always beware of heat build-up. The whole assembly will absorb heat cumulatively, unless heat is allowed to dissipate. Nothing is more frustrating than to have the whole lot disintegrate as the last part is soldered. It's a good idea to invest in some small G-clamps and steel bars which can be attached to either side of the seam to act as heat sinks.
Cleaning. Flux will leave a corrosive residue which will colour paint if not removed. It can be removed mechanically with wire brushes and abrasives but a better way is to neutralise with acids, such as citric:
http://www.armortek.co.uk/Forum3b/viewt ... f=2&t=5486
You end up with something like this:
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That's about it. The three key principles are: clean the surfaces, hold the work firmly and apply sufficient heat. It's great when it all works and hugely frustrating when it doesn't but worth every effort.
As ever, comments and additions always welcome.