"Morris Dovey" wrote in message
...
On 5/5/2010 7:51 PM, Bill wrote:
"Morris wrote in message
...

Next up: learning to braze with an oxy-acetylene torch...

Much like soldering. Distribute the heat where it needs go and the
(fluxxed)
braze will flow nicely Don't tough the tip to the work! ; )
In my (limited) experience, the faster you get it done, within reason,
the
better it will look. Incidentally, in one related experiment I did, I
noticed the heat caused the the garage floor to disintegrate. That
happened
30 years ago, but I suspect garage floors haven't changed that much!
Probably you already know all this, but I enjoyed writing about it. Have
fun!

I've watched a number of YouTube videos, and it does look much like
soldering. My plan was to hold the long tube vertical in my vise and braze
the brass fitting into place - then, before it could cool, stack on the
short tube and braze that to the top of the brass fitting. Then, after
everything had cooled to room temperature, add the cap to the top of the
short tube and braze that in place.

Actually, I hardly know anything at all about what I'm doing - and AFAIK
no one has ever built a pump engine like this before. It's a great
adventure. If it works as expected, the next version will be solar powered
with an operating temperature ~1000°F.

The shop floor will remain safe for a little while longer.

Thanks for the speed advice - and for the warning about concrete!


The melting point of brass is about 1700 degrees and that of stell is about
2700 degrees (see
http://www.muggyweld.com/melting.html ).

That makes your brazing problem much more delicate, I think, than the ones I
worked on.
You will use a brass brazing rod of course, and I'm sure you will practice
with the material
before you apply the heat to your good one. Alot like me and my M&T
joints..! : )

Bill



--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/