A belated Happy Christmas to you all, and I hope 2021 brings relief from these Covid troubles. This blog had to be kept secret for reasons which will soon become clear.
Carboys
If you are old enough to remember, it was traditional for a chemist shop to have a carboy in the window, filled with coloured water. My wife was a pharmacist (I can say that in the past tense because she let her qualifications lapse last year) and we have this carboy in our study window.
When I was hunting for inspiration for a christmas present, I hit upon the idea of a tiller pin in the shape of a carboy to bring a reminder of her profession into our boating days. A quick Google resulted in dismay. No-one makes a carboy tiller pin. What is the world coming to, I ask?!?
As this was such a good idea, I decided to set to and make one.
Turning Time
I inherited a small model maker's lathe from my father, and so I could turn this very circular shape. The size was limited by the chuck size of the lathe, and I bought a stainless steel bar long enough to make two, on the assumption that I was going to mess up first time. With some excuse about needing to tidy up my shed I set to and started turning.
Here are one half of the bar, the part turned shape at the stage when it was turned around, and the pin itself.
Suffice to say it took a while as I had to remove the bulk of the metal, but eventually it was done. A bit of polishing (everything I wore became red with jewellers' rouge) and it was almost ready. Dad had left me a box of assorted fluxes and rods, and I picked one which looked like brazing brass. With the joint between the pin and carbuoy suitably coated in borax I attacked the joint with blowtorch in one hand and rod in the other. To my surprise it melted quickly and to a bright silver colour, so I suspect I silver soldered the two together. Hey ho, there's not much force so it will be fine. It certainly won't rust.
The Finished (?) Item
As a result of the jointing heat, the pin gained some colour which I quite liked. Here it is, as presented on Christmas day. It differs in shape because the diameter was limited by the lathe capacity, and I made the top intentionally blunt to avoid risk of injury. The blue base is where it was held in the chuck.
What did the boss think? Suffice to say, my next job is to polish it to remove the "tarnish". Apparently stainless steel has to be, well, polished stainless steel and not these delightful blue, orange and yellow hues.
So when you see Perseverance on the cut next year, this is not the colour of the pin you will see.
You could use pickling acid
Mixtures of nitric and hydrofluoric acids are usually used for pickling stainless steels. Pickling is the process used to remove weld heat tinted layers from the surface of stainless steel fabrications, where the steel's surface chromium level has been reduced.