Sunday, 16 October 2016

Copper Chimneys

Hello.

For a couple of upcoming projects of mine I needed a source of some GWR type chimneys. The original plan of mine was to use some bits from the excellent range of castings that Nick Tilson of N Brass produces. The thing is his castings are in Brass and I wanted to do the distinctive copper capped chimneys that so many GW engines had so this is my solution...

First I found some great little blog posts that Paul has done HERE which show in fantastic detail how he produces them. This seemed the ideal way to try making my own but, once again, they were Brass. My idea was then to do some research to find out what the best grade of Copper was to machine as there is a good range of alloys available, some of which are a pain to machine. The final decision went to some C109 Copper and was duly ordered via Ebay  HERE

Once the Copper had arrived and I have time I firstly scales a works drawing for a chimney which provided me with the dimensions I needed so then I promptly made a start. My plan was to make the whole chimney out of Copper so once it is painted the top could then be polished up, looking all GW.
Machining the Copper was a dream, it cut really well and left a good finish. For your information the plaster covering a cut isn't due to me being clumsy on the lathe, its from an earlier DIY job!
Above shows what they look like after being turned on the lathe. It took a couple of attempts to get some which I was happy with, the chimney on the far left of the picture is one of those failures. I decided to keep it so I had something to experiment with on the next step. The steel bush was also required for the next bit.

As per Paul's posts the next step was to hold the chimney in position and then form the base around a suitable bar similar to the boiler diameter. I used (ironically) the copper bar which was used to make the chimneys from and my manual milling machine.

So above are the finished chimneys. Thanks to Paul the whole thing went well and definitely weren't as daunting to make as I first thought. I now have much more confidence making bits for boilers.

Julia.





10 comments:

  1. Julia,
    I'm absolutely delighted to see that you've turned up some super chimneys, and that you found my ramblings usefull!
    I'm also intrigued by C109 copper, I shall have to order some and have a play. I have turned copper in the past but never managed to get a decent surface finish.
    Paul.

    ReplyDelete
    Replies
    1. Thank you Paul.

      If it wasn't for your 'ramblings' I doubt I would have tackled such things but stuck with the cast ones instead.
      I would recommend the Copper, it surprised me how well it cut compared so some real horrible stuff I have used in the past. Its not that expensive either.

      J.

      Delete
  2. They look pretty darned good to me Julia. Well done.

    BTW, I've also heard of people copper plating chimneys made of other metals. Sounds like it would work in theory but never having made a chimney I have no idea. I did copper plate a few things when I had a chemistry set as a kid though.

    ReplyDelete
    Replies
    1. Thank you Andrew.

      I have heard about the plating thing too but never actually seen any results. Machining them was easy enough to do once I got the hang of how to do it so I think I will stick with that.

      J.

      Delete
  3. Very nice Julia. I used phosphor bronze bar for the chimney on my Metro. The one on my saddle tank is brass that I copper plated in a solution of copper sulphate. I tried copper bar that I had from Chronos and it was a complete disaster, just didn't machine very well at all.

    ReplyDelete
    Replies
    1. Hi Ian, thank you.

      Andy H suggested Phosphor Bronze to me before I started but my thinking was I might as well use Copper if the originals were Copper. I'm interested in the plating thing though as you have proved it works. What sort of thickness do you think you got plating it? Copper is fickle, as I mentioned in the post I did a bit of research first before deciding what grade to get, I would recommend trying the C109.

      J.

      Delete
    2. The copper plating I did is extremely thin, I had to be careful not to burnish it off. It was the first time I'd tried to do it, and used a PP3 battery to power the operation. I don't know whether that was too beefy, I must admit that I didn't do a lot of experimentation.

      Delete
    3. Thanks for the information Ian, that is very interesting. Its obviously worked on your excellent engine so its not something to dismiss. I am sure with a bit of time and experimentation the results could be much better.

      J.

      Delete
  4. These chimneys are delightful little jewel-like things...and although I suspect you would deny it, they are the product of considerable skill. It's very nice to read about this and vicariously experience model engineering :-)

    ReplyDelete
    Replies
    1. Thanks Ian. To be honest once I had figured out how to make them it wasn't that difficult to do hence making several of them. We all have our own skills in this hobby, I wish I could produce the beautiful things you make.

      J.

      Delete