James Spooner Boiler making

Ref: Fairlie Locomotives of North Wales: David Payling : Ffestiniog and Welsh Highland Railways 2017.

Andy Cooper made the parts. Trev Oughton fettled the parts and then soldered them together. That's the difficult and skilful bit!

First make all the parts. 2" copper tube for the barrel and 19mm for the flue tubes. 16 gauge for the ends and boiler joining tube which has baffle plates in each end to help prevent water sloshing through when the engine has to start quickly because the regulator will be open and priming might take place. When stopping this will not occur because the regulator will be closed.

All bushes are 5/16 x 32 phosphor bronze. Fit must not be too tight otherwise the solder will not penetrate the joint.

If you are turning copper use pure spirits of turpentine as a cutting fluid applied with a soft brush.

photo: Andy Cooper

The basic design has two of everything. two boilers; two water gauges; two Goodall fillers, two safety valves, two burners, two gas tanks and two gas valves, two lubricators, but only one regulator and pressure gauge. Here you can see the baffles in the joining tube.

Then check that the parts maker has made them properly!

Test the end fit...not to tight..not too loose...

Checking for squareness of the two boilers using vee blocks

Checking that all the bushes line up

Mark a line inside the barrel where the end plate will go

and then using a graver make small "curls", called " Jewellers' Stitch", that will locate the end plate and stop it falling inside the barrel when soldering takes place

Stamp the boiler before it is assembled so that it can be supported by a large steel bar. It can then be identified when it is tested.

Making the circles of silver solder using the boiler barrel and flue tube as templates

Fit the end plate in position, put in the ring of solder and then apply flux liberally. You don't want the flux to burn away before you have finished heating the joint.

Heat up so that the solder runs into the joint making a fillet.

Soak in acid bath to clean at each stage. Cleanliness is very important.

The end product and checking that the solder has run all around the joint

Roundhouse water gauges were used on each boiler.

The first picture shows the gauge support wired in place and the through copper tubes. The second shows the bushes and gauge support fluxed in position ready for the higher melting point solder.