Friday, November 29, 2013

Forging Hot Collars


I did a web search for the Francis Whitaker hot collar formula.  It is illustrated in his “Blacksmith’s Cookbook” and I’me heard many people recite it.  It wasn’t so easy to find on the web so I decided to do some SketchUp illustrations and post them the the 3D Warehouse.  When I tried this morning I got the message that “The service is not available.  Try again later.”  So, I plan to do that.

In the meantime I’ll post images of some illustrations I drew.  The show the Whitaker formula and the sequence of steps in the forming process.
Bill Fugate published the formula in the Pittsburgh Area Artist-Blacksmith Association newsletter in July 2010.

Carl Davidson published a nice article in the Northeast Blacksmith’s Association Spring 2012 newsletter showing how to modify and Engineer’s wrench into a neat adjustable collar making tool.  I couldn’t find a link to it just now.


Next time I’ll illustrate another way to make collars which I learned on a visit to Flicker Forge.

The Francis Whitaker Collar Formula 
Starting the collar forming after calculating the collar length and beveling the ends.  Francis suggested finding the CL then moving over one half the width of the waterfall to be collared to start the first bend.  This should get the lap pretty well centered.

A mockup of the workpiece can serve as a mandrel to be used with the vise. 
The collar can be finished on the mandrel and opened to fit or the final two bends closed over on the workpiece.

Sometimes is most efficient to form a batch of collars on a mandrel and open them up so they can later be fitted and closed on the workpiece with torch heat.

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