"Paul Drahn" wrote in message
...
On 10/26/2013 5:46 AM, Jim Wilkins wrote:
"Paul wrote in message
...

I lay awake last night trying to understand how it all worked and
the errors made in the tour guide talks. One big question is what
they used to bind the sand and clay to make molds. Could they have
used lard oil, or other animal products?

Paul

Normally the clay is enough. For fragile internal cores molasses,
flour, linseed oil can be added, and baked to harden it.
http://www.imarketingcenter.com/coresand.html

jsw


Ok, sounds like that would all have been available in 1776.

They cast lots of cannon. Assume the buried the mold in the sand so
the molten iron could flow into the end of the mold. What did they
use to form the bore of the cannon? Did they mold a ceramic ( tiles
stacked up) or some other material?

Paul

According to master caster Vannoccio Biringuccio the bore core is an
iron rod coated with first rope, which burns out and permits removal,
then clay mixed with "a small amount of cloth clippings and much
sifted horse dung and some washed and clean wash ashes". The rod is
suspended from end pivots as a simple lathe, with a board set parallel
to define (scrape off) the diameter as it's rotated and packed with
clay. Within the mold metal spiders that become part of the cannon
center the core.

Become a Renaissance Man yourself:
http://www.tms.org/pubs/books/pdfs/0.../09-1002-0.pdf

John Wilkinson invented efficient methods to bore cannon and steam
engine cylinders accurately.
http://en.wikipedia.org/wiki/John_Wi...(industrialist)

jsw