In article , "J. Clarke"
wrote:

On 7/31/2010 1:32 PM, Joseph Gwinn wrote:
In , "J.

wrote:

On 7/31/2010 12:21 PM, Joseph Gwinn wrote:
In ,
Tim wrote:

On 07/31/2010 08:26 AM, RicodJour wrote:
On Jul 31, 10:24 am, "J. wrote:
On 7/31/2010 9:44 AM, Joseph Gwinn 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.

A charcoal fire will do the trick, and most jurisdictions allow
grills.
It's
the smoke they object to.

How big is the tire?

sigh Count up four paragraphs.

I counted up four paragraphs and it said some thing about finding a
blacksmith, but nothing about the size of the wheel.

How big is the wheel? {ducking}

"The wheel is 2 feet in diameter, making the tire too big to fit in a
barbecue or the like."

The diameter (2') is only one of the three needed numbers. What is
thickness
and width?

An inch wide, 3/16 thick.

Ahh. That's reasonably substantial. Thinner would be harder to keep hot
using a torch. I bet a propane weedburner would do the job, especially if the
heat were confined with some firebricks.

That's another good idea, appeals to the small boy in me, and is cheaper
than an oxyacetylene rig.

Also, the heat content of acetylene is far less than that of propane, so propane
is better for bulk heating. I learned this from a book on brazing and silver
soldering. The author is a UK model builder, and he makes silver-soldered brass
boilers for model steam engines.


So should I go for the 500,000 BTU Red
Dragon, the 100,000, whatever Home Despot has, or the 12.99 Harbor
Freight jobbie?

I have a Home Despot weedburner, and while it does work, it is awkward to use
because it lacks a built-in lighter, so you cannot turn it on and off so easily.
An ordinary spark lighter didn't work, and I ended up using a small propane
torch as a lighter. Clumsy. So, I would recommend getting a unit with built in
lighter. I'll probably buy one someday.

I have no experience with the HF unit.

I would think that 100,000 BTU/hr is enough, but you will need the firebricks to
make a simple muffle to contain and focus the heat.

If you can manage the charcoal ring fire, that may be easier. Use the
weedburner to light the charcoal. Firebricks are still useful. Or half-bricks.


For doing hot work on my wooden workbench, I went down to a local brickyard and
bought $35 worth of ordinary firebricks and half-bricks. (Have the shape and
density of an ordinary red brick, but are yellow; used to line fireplaces.)
When I need to do some hot work, I make a cleverly arranged pile of bricks on
the bench and get to work. With a muffle, I can easily get small objects up to
a bright orange heat. After it all cools, the bricks go back to their storage
pile. The only scorch marks on the bench are where I didn't pile enough bricks
in place, and some flame spilled over the edge and impinged on the wood. The
backside of a full brick does not get hot enough to be a problem.


Wish I'd thought about using one of those when I was trying to get my
muffler off a while back, but I'd have probably just set the Jeep on fire.

Unh. Too much of a good thing.

For a muffler, I would guess that an air-acetylene turbotorch would work. Or
air-propane turbotorch. But I've never had to use a torch on a muffler. It was
cheaper in time to simply cut the entire old exhaust system off right up to the
cast iron manifold using a cold chisel, and replace all that rusty tin. At
least on the Volvos of the day, with care you could perhaps save the long pipe
(which ran the hottest and so corroded the least), but it was not worth the
trouble.

Joe Gwinn