Sunday, May 27, 2007

Boiler 2

I decided that I didn't want to cut holes in any of the plates until I'd formed the firebox wrappers - so I started on those next. One way to form them is to make a wooden template and beat the annealed copper around them. Or you can form the sheet using bars of the appropriate diameter, which was the way I chose to go ( not being an enthusiastic woodworker !)

Once annealed, the copper is incredibly soft, and needs little more than hand pressure to start to form it. I used various formers, as the pictures show. This firebox has a combination of inside and outside curves (most do) which makes it arkward.
I just bent a bit at a time, checking against the flanged plates. A good fit is important, as silver solder has no gap filling properties.
When the copper stops bending easily, its time to re-anneal. It took me five or six heats to get the inner firebox wrapper to my liking - less for the outer.
Incidentally, I deliberately left the sheets oversize; putting lots of bends and folds in sheet is difficult enough without having to worry about having enough length - the first fold on my outer sheet ended up 1/4 inch from where I'd planned it, so I was glad of the excess. I won't trim the excess length for a long while yet.


Tonniece said...

Hi Norman, I've been a bit remis in dropping by, but Dianne has kept me up to date.
Although it's a well kept secret, Dianne is willing to try anything and usually gets me involved too, BUT, this is truly amazing and one something I'll not try to attempt. lol
I do so enjoy reading all the how to's though. You give great visual and editorial tutorials just like Carol.

Thanks for sharing your unlimitless knowledge.


Dianne said...

Wow Norman the copper looks like a piece of art all on its own.. Beautifull, I know you will use it for your train but it so so beautiful.... I agree you both are great teachers, you have a great way to make it understanable..
I learn something ever time I come here....