This weekend the temperature in the workshop shed dropped below 0°C so the electric heater was set going. It’s only a little workshop and I’m not working long hours so I’m not too worried about the cost.
However the cold did determine my choice of jobs, I decided to practice brazing small sheet brass, approx 10mm square by 0.5mm thick. I’d bought some braze and flux from CupAlloys at the Model Engineering show at Ascot back in September. After a short discussion with them about the need for a significantly bigger torch if I was going to repair the gates on my drive, I focused on the smaller brazing requirements and bought some small brazing rods. These were slightly more orange than usual hence will look good when used with brass.
I had also bought some helping hands which I now used to hold some small pieces of brass sheet in place whilst I brazed them together. I disconnected the magnifying glass and used its fittings to hold some surgical clamps so that I could hold three pieces at once and braze a corner. I found that my small torch did have enough power to get the metal up to temperature but the best results were achieved by pointing the flame vertically down onto work. It was hard to see if the brass was glowing orange but the clips of the helping hands were. I’m not sure if repeated use in this way will soften the springs but I can always replace the clips if necessary.
The plan is to make a second identical corner and then use low temperature solder to attach the two pieces together. The resulting cube will be used to test out the aging technique using copper sulphate.
One thing to lookout for when buying helping hands is the kind of wingnuts used. Mine was cheap and used wingnuts pressed from sheet metal. One of the nuts had already failed by the time I got to use the hands so I’ve ordered up some new stainless steel wingnuts off of ebay and will replace them all.