No 7 (or 27)

By Journeyman

I recently acquired enough volumes of Model Engineer magazine to complete my collection from 1944,  and now have them all bar a recent number which the Royal  Mail lost! I enjoy ‘catching up’ on what I have missed over the years and have now read them all!

Two letters appeared in the Post Bag about hardening and tempering ordinary carbon tool steels, like silver steel, and this was a problem that vexed me all my blacksmithing career, and in particular the hardening part. ALL the books and conventional wisdom say to quench out when the steel is cherry red. But just what is cherry red ? The ones from the green grocers are either of morello cherry deep purple/red, or almost black, being a temperature far too low to effect hardening, or a pale reddish yellow which would be far too hot and untemperable, leaving the steel very hard but uselessly brittle.

The answers from Andrew Breeze and Stan Bray agree that the colour to achieve for hardening is that of a boiled carrot. In addition, both this work and silver soldering should be carried out in subdued light, as would be found in a typical village forge, or similar to the light in the garden at dusk.

As you know, once hardened the surface of steel has to be brightened up with some emery or similar fine abrasive, but Stan says that if you dip the steel in washing-up liquid prior to bringing to ‘carrot red’ it will remain clean after quenching ready for tempering. Small items can be tempered on a bed of dry sand gently heated from below to the desired colour., although a good friend of mine did not have much success with this method when trying to make injector jet reamers.

Those of you who have been following my jottings from early on might be wondering what has happened to my 5” g. Stroudley Terrier. Before we decided to leave The Styx in Devon I had the loco complete and running well under air. So the time came for painting, a job that seems to be one that many model engineers dread, and I am to be numbered amongst them. However, the job had to be done so I dismantled it down to the last nut and bolt, did a lot of reading, bought an airbrush and small compressor and then came the question of paint.

I spent a lot of time on the net following up paint types and other suppliers and talking to people about the process. Books, quite frankly, aren’t much help unless you are prepared to spend a great deal of time experimenting with different paint types and degrees of thinning, so despite spending quite a lot on the stuff all my efforts were in vain, and what went on was stripped off, the house move loomed and it was all packed up and forgotten.

Eventually I decided that the sensible thing was to have the job done, and so after all the parts had made a journey ‘oop North’,  I set to and started the final reassembly of my pride and joy. The job was not wholly of the quality I had hoped for, but after such a long gestation, some 47 years or so, the priority was to get the loco back together and in steam. So far the frames and motion are up and running and tested on air, and the boiler has been given a 1.5 x hydraulic test before mounting back into the frames. This allowed our club Boiler Tester to see it without any cladding or fittings, and I have already done a test myself on my recently completed pressure testing rig. I have also used it to test the pressure gauge, superheater and clack valves. So far so good.

Much time was spent in ensuring that no parts were inadvertently left out necessitating much unwanted subsequent dismantling to fit a part that had gone awol. As I proceeded I realised that I had not been very thorough in bagging and labelling all the nuts and bolts and there has been a lot of searching for those that finished up in some random pot or bag.

Another problem that has arisen is that I made many parts to too close a fit, and am now finding that I am having to do quite a lot of filing to accommodate the thicknesses of paint that were applied, rather thicker than is necessary for a good finish. The running boards would not fit between the buffer beams for this reason and filing them shorter has entailed much care to avoid damaging their finishes. Also, for reasons I just couldn’t fathom, the right hand water tank was obstructed by the firebox expansion bracket hold-down clip, so a much shorter and thinner one had to be fitted.

However, it is coming together and beginning to look like the finished locomotive that has gripped my imagination for so long. I would never recommend to anybody to allow such a project to take so long, nor to be persuaded that it is suitable for a beginner. The inevitable gaps in the construction lead to a loss of continuity, and it will certainly show in my loco, now named after A1 0-6-0 No.43, Gypsyhill.

Some time has elapsed since I wrote all the above, and to my amazement, Gypsyhill is finally finished, all bar its first steam test.

I must confess to a sense of anti-climax, long gestations are always followed by a sense of ‘what next ?’ , and that has yet to be decided upon, and as my mentor Norman said, it’s very rare that nothing needs attention following the first steam up, and so whilst expecting a snag or two, I’m hoping I’ll get away with a smooth run and give the little lady a bedding- in run on the rolling road as she, like me, is a bit stiff, but not of course from advancing years!

So I can’t predict when there will be something new to report, but hope it won’t be long.