CH> I'm probly going to convert an old lawn-mower motor into a 
 CH> steam engine. Sounds a lot easier to me. Just change the cam's 
 CH> valve timing. There are many auto speed shops that do custom 
 CH> cam work here in the USA.
Yup,  all you need to do now is find an old lawnmower that uses a V-8!  :-)
 CH> The first stage is made out of metal and a large diameter 
 CH> because of the high temp and volume of the steam. This will 
 CH> have many heat sinks soldered/brazed to it, both inside and 
 CH> out, to bring the temperature down rapidly, turning the steam 
 CH> into a vapor/steam mix, reducing volume and pressure.
Don't expect solder to work well at steam temperatures...

 CH> The whole thing will be built in several stages. After the PV 
 CH> system is up and running to provide initial power, the solar 
 CH> furnace will be built. Once it's built, I can use it to melt 
 CH> metals for use in building the boiler and coils. I'll melt down 
 CH> lead from old batteries and add tin to make solder which will 
 CH> be used to coat the steel drums to prevent oxidation, and 
 CH> install the heat sinks. It will also be used to heat the 
 CH> soldering irons used in many stages of developement. 
This is a real *BAD* idea.  Every so often I see the suggestion come up of 
using lead from old car batteries to make bullets.  I usually jump on that 
when I do.  You're not talking metallic lead,  for the most part,  but lead 
sulfate and lead dioxide,  alloyed with Antimony or Calcium or other metals. 
They add stuff to reduce water usage and there's no easy way you're going to 
separate it out.
From what I understand,  battery mfr's like Exide have smelters to recycle 
the materials from junk batteries that come in,  and everything I've heard 
about those places says that they're rather *nasty*.  Not something that an 
individual would do well trying to set up.  And,  they shut 'em down during 
the middle of the summer.
 CH> The high pressure water tanks will have to be welded, so it 
 CH> won't help there. However, the furnace can be used to melt down 
 CH> old batteries to reclaim the metals, for sale or use.
FWIW,  they also recycle the plastic case material to make new batteries (why 
do you think so many of them are black?) and the acid gets processed somehow 
to make fertilizer... 
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