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The original mast consists of 3 separare parts - the crow's nest (single pressing), the mast and the horizontal spar, all soldered together, probably in a simple jig. The repro mast is a little more complex to make as the crows nest is itself fabricated from 2 pieces...
The crow's nest is made from a short section of tubing (17/32" OD), soldered to a flat plate, which is then trimmed and fettled to make a brass 'bowl'. A hole is punched in the botton and the mast inserted in the the hole.
The section of tube can be cut in two ways - a pipe cutter or using a saw. Both methods are used as the pipe cutter produces a slight radius (for the base of the bowl) and sawing doesn't (for the top).
When using a pipe cutter, take plenty of time to cut the pipe and only wind in the cutting wheel a small amount each time.. Spin the cutter at least 10 times between winding in the cutter. If you don't, the thin pipe will deform.
A 3.5 mm section of pipe needs to be cut. The straight cut is made using the type of extremely fine saw used in jewellery making (sold on-line or at Hobbycraft). The saw is used in the vertical plane and cuts on the down stroke (so the blade needs to go in the right way round). To get a straight line, wrap the pipe with masking tape to create a 'shoulder' to cut against. Note the simple notched piece of plywood clamped to the table... make one of these and cut the pipe on that.
The slice of pipe should be rubbed on a completely flat block and then de-burred. It's very important that the surface to be soldered is very accurately 'flat' otherwise the soldering won't work...
Once the ring has been de-burred, it should sit perfectly 'flat' on a square of brass. So the brass needs be completely flat too. If it's not, use smooth jewellery making pliers to gently straighten it. To prepare for soldering, both pieces should be polished to a shine with 000 grade wire wool.
Flux is carefully added using a small paintbrush - make sure there is flux between the pieces. The flux can be bought from B&Q. Unlike plumbing, flux is placed on the piece BEFORE the heat is applied. This is a technique used in silversmithing... It means that the temperature of the job can be very carefully monitored and gauged... (because too hot will wreck it!)
Cut tiny pieces of solder (I use electrical solder from B&Q) and carefully place onto the work with paintbrush... move them into position with a pin or a blade. Very little solder will be need to solder the pieces together, so the more that you put on, the more will need to be removed afterwards!
The soldering should be done with a small 'pen type' re-fillable blow torch. Mine cam from Maplin (I think) and is a gas soldering iron with the soldering tip removed. The flame should be the small - about 1/2" long. I solder with the piece on a flame proof ceramic block - obtained from jewellery making supliers.
The pieces should be heated *slowly*, moving the flame around the piece so that no particular hotspots form. The piece will go through the following stages:
1 - the flux will melt and run clear
2 - the flux will start to sizzle and evaporate and the piece will start to discolour. At this stage, it may spit the solder off - if so, quickly re-position the solder.
3 - the solder will melt and form little blobs in situ
4 - the solder will suddenly 'flow' and will be sucked into the joint by cappiliary action. Stop applying heat as soon as this happens
Once soldered (above) - the excess should be trimmed off using tin snips. Snip off small parts at a time and trim as close to the sides as possible.
Carefully file away the excess metal, putting smooth radius on the bottom. Use needle files to take a away the bulk, then fine wet and dry on a small block of wood to take out the file marks. Finish with 000 wire wool and polish to a shine. Seems a lot of work but this can be completed in about 15 minutes.
Once the crow's nest has been fettled and polished, a hole must be made in the middle. Mark the centre of the hole (with a felt pen) and use a centre punch to mark the hole. Do this on a soft wooden surface so that the metal is allowed to deform.
Then use a bradall to punch a hole in the bottom (just as Sutcliffe did). Again, do this over soft wood, and make the hole bigger gradually... the mast should be a tight fit in the hole (as picture above).