On 7/31/2010 10:13 AM, Larry W wrote:
In ,
J. wrote:
Working on a decorative wagon wheel in wood, but I'd really like to put
a metal tire on it. Now, that's no trick if it's just for looks--make a
steel ring that's close enough to the dimension that a little epoxy
under it will hold it, but the devil in me wants to do a proper job and
shrink the thing.

Trouble is that this is a no-burn area so I can't just light a fire in
the back yard and heat the tire.

So, any ideas on how to go about this? The wheel is 2 feet in diameter,
making the tire too big to fit in a barbecue or the like. If I was
making a bunch of 'em I'd be tempted to just build a charcoal pit big
enough and call it a barbie, but that's a lot of work for one wheel.

And yeah, I know I can find a blacksmith, but I'm more interested in the
making than in having a wheel.

2 feet in diameter is about the size of a large pizza. Will it fit
in your oven?

No. 21 wide by 17 deep. There's also the question of whether it gets
hot enough for good take-up. The tire doesn't just have to fit, it has
to be a little undersized when cold so that it loads the wooden parts in
compression--that's where the strength of the wheel comes from. 500F
will give about a quarter inch of expansion with low carbon steel, red
heat will give close to a half inch. The various 1800s and early 1900s
blacksmithing journals suggest that the iron in use at the time would
expand more than this.

By the way, the large pizza from the big chains is 14-15 inch, the
independents may go 18.