Metals

stfx · Post by **stfx** » Mon Aug 02, 2004 8:03 pm

Well, I not gonna use stainless steel for my first project, so i was loking at some alternate metals. Copper primarily but the problem is that it starts to melt at 1356 degrees celsius and propane (the fuel i want to use) reaches up to 1925 degrees celsius (with air) and even butane is at 1895 degrees celsius (with air). So I was wondering if any of you used th8is set up before and what problems you ran into ( and how you fixed it).

Mark · Post by **Mark** » Mon Aug 02, 2004 8:51 pm

Iron melts at 1535 C. You would have to use alcohol with copper and maybe even add in a little water once it gets going. Copper would be good for short runs easily.
Maybe you could coil your tubing around the copper tubing and keep it cool that way, use the cooling from the evaporating propane to cool the jet, like they do with rocket nozzles and liquid hydrogen.
Mark

yipster · Post by **yipster** » Mon Aug 02, 2004 9:32 pm

Metals

or keramics?

Tom · Post by **Tom** » Mon Aug 02, 2004 9:34 pm

Not the ceramics thread again...

*sobs quietly*

Tom

stfx · Post by **stfx** » Mon Aug 02, 2004 9:50 pm

i don't wanna get into cermics or cermic coatings, even though it can withstand extreme heat it so incredibly expensive.

So i guess what im gonna do i use copper and propane, but once i get started im gonna take the hose and pour water on it as it gets hotter, this is just a prototype just so i can see what will happen, if I get it working ill use better metals.

Mark · Post by **Mark** » Mon Aug 02, 2004 11:02 pm

That's the ticket, who cares about a prototype, all you are doing is testing, why spend a lot, wait until you know what design suits you best. You might even mix and match, use copper for the tail pipe and other tubing for the chamber or vise versa. Keep it simple. Therein lies the fun of it.
Mark

Mike Kirney · Post by **Mike Kirney** » Wed Aug 04, 2004 12:17 am

Coffee wrote:Not the ceramics thread again...

*sobs quietly*

Tom

Whatever became of the clay jam-jar you were making in your pottery class?

By the way, stfx, ceramics are not expensive at all. Ordinary pottery clay is ceramic, as is porcelain. Both hold up to extremely high temps very well. It would be quite easy to make a ceramic jet but one wonders how long it would last with all that vibration. You can go to a masonry outlet and get glass whiskers to mix into your ceramic to add great strength. While you are down at the brickyard, ask about 'castable refractory'. I bought a 50 lb. bag for about 40 bucks last winter, but have yet to use it, so I can't tell you how good it is for jets. If you are going to build your jet out of metal, you should know that the V-1 flying bomb engine was made entirely from mild steel, and that using stainless steel is entirely unnecessary:

http://www.jetzilla.com/Vol01Num03/jetZ ... #Article_1

Tom · Post by **Tom** » Wed Aug 04, 2004 12:20 am

It sat here, ran for a short while, only a few cycles, now sits in my draw taking up space. Still it worked, didn't crack either.

Tom

Mike Kirney · Post by **Mike Kirney** » Wed Aug 04, 2004 12:27 am

Coffee wrote:now sits in my draw taking up space.Tom

Pics please?

sparks · Post by **sparks** » Wed Aug 04, 2004 2:48 am

One of the "start-kabooms" my little engine makes would crack just about anything.
I even thought my bedroomwindow was in danger when i first started it 4 meters away.
But i may consider cheramic coating on some hot-spots.