[TheForge] Re: Advice? Air hammer die and anvil fit-up

Sat Jul 12 00:37:00 2003

Charles wrote:

> Cast Iron has great strength in compression, but has relativley poor
> strength in tension or shear ( the reason so many dovetails are
> broken off power hammers,

Yeah.  The edge of the dovetail slot in the anvil is badly chipped,
too, but I think there's plenty to hold the die if I make a good,
full-length wedge.  It also has a key in the side opposite the wedge
that will prevent the die from moving lengthwise along the slot.

> As far as lowering it, the traditional method would be a cape chisel
> to create grooves, followed by cold chisel, followed by files.

Right.  I did know that.  I was hoping someone would have had
experience using a belt sander and could tell me it would be easier and
faster that either chisels or  grinders.  I *am* going to have to do
some chisel work on the keyway mentioned above.

> M.T. Richardson's Practical Blacksmithing quotes a reasonable
> repeatable days work with a chisel to be a 3/4 " wide, 1/16 " deep
> groove 600" inches long in cast iron.

Gee, that's 3 square feet of surface.  I'll have to fool with that a
bit.

> Personally, for what you have left, I would use a 16 inch nicholson
> double cut file.

I use small files and a 10" mill smooth or mill 2nd cut a lot.  I
don't think I even have a big mill/flat bastard.  Cut down two
ca. 5"x12" surfaces by 1/16 or so?  Seems like a whole lot of
filing. Maybe I've underestimated the power of big, coarse files.

> ...no sparks or embers flying into every ship recess.

In the case of cast iron, it's graphite dust everywhere.

   "You're not just dirty.  You're *incredibly* dirty!"

- Mike

-- 
Michael Spencer                  Nova Scotia, Canada 

[email protected]            
http://home.tallships.ca/mspencer/