Hello again, fellows. I have found all of your answers to be thought-
provoking. What stirred me to ask the original question is that is
that for years I have been hearing about soldering, brazing, and
welding techniques being used to build up engines, but until I
discovered Roy Shepherd, I didn't have a good example to follow:

http://www.royuk.co.uk/steam_engines.htm

I sent Roy an email, and he says that he has learned that plumbing
solder, and even electrical solder is okay for these engines.
Considering the easy availability of these soft solders, I have
decided to use them myself for the same purpose, though I do expect to
get to the point where I will need to move to a hard solder instead.
I will have to make a longer drive to get some silver solder, but I
will be able to purchase that locally also. Considering the cost of
solver, though, I think that in the long run, I will be better off
using a hard solder with no silver content. Does anyone have any
recommendations?

Mike Mandaville
Austin, Texas