Saturday, August 2, 2014

Canopus: Retubing the Boiler

While I never expected that the kit for Canopus would be easy to put together, I hadn't expected to hit quite so many issues as I have so far. Prior to this post I had used six etched parts, one of which I broke and one of which I destroyed and had to replace. Rather foolishly I hoped that the next step would go together easier.

Having assembled the cab the next stage involves fitting the smokebox, boiler and saddletank. This actually involves four parts as the boiler consists of a brass tube and a cast whitemetal weight. The other two parts are also whitemetal castings (the kit includes both a cast and etched saddletank but I'm using the cast version as it is heavier). The bottom of the smokebox needs a hole drilling and tapping to take the other fixing screw (the first one is at the bottom of the coal bunker) that keeps the body attached to the chassis. This was easy to do as there is a dimple in the casting to aid correct positioning. Having test fitted the smokebox to the footplate I found that the boiler wouldn't fit.

The problem, as you can see from the first two photos is that while the instructions say that the saddletank "should be a snug fit against the cab ... so that it just touches the smokebox" both the boiler tube and weight are longer than the saddletank casting. The solution is easy, although rather time consuming.

First I used a razor saw in a small miter box to trim the brass tube to a more acceptable length, before then filing it to an exact match to the length of the saddletank. I then filed the whitemetal weight down until it was the same length as the brass tube. Having test fitted the parts they do fit although I haven't yet had the time to actually glue and solder everything into place so that will (hopefully) be a job for tomorrow.


  1. It's certainly a rite of passage, this construction - and I admire your patience and determination. I suppose the niggly but nevertheless almost deal-breaking faults are typical of cottage industry suppliers, who probably don't have the means at their disposal to ensure consistency. Having said that I have a High-Level Barclay tankie that has been waiting for over 10 years for me to start it and the parts are beautifully made and fit perfectly ( I have made many "dry runs...not that it has seen a soldering iron yet!). Anyway, as always, this is an entertaining and enlightening build.

    1. I can kind of understand the brass pipe being slightly out and needing a little work for a perfect fit, but what I don't understand is why the boiler weight casting was out -- you'd think the masters for the two parts would have been made to be a good fit to each other. At least so far none of the problems have been too difficult to overcome.