Mach25 Posted August 4, 2011 Posted August 4, 2011 Anybody ever cast any nozzles parts? I have several spin casting machines which use a thick circular silicone mold. This was used for spin casting pot metal that I used for a project many years ago . I also cast zinc if I needs a harder part. Of course zinc melting temp is fairly low so I have no idea if it would every hold up to the thrust of an AP propellant. I also have a vulcanizer for forming the molds. Purhaps there is an angle there..
dagabu Posted August 4, 2011 Posted August 4, 2011 If you are talking APCP fuel then no, the zinc will melt like butter. Graphite rod is often turned to the nozzle profile as it will not erode at high temperatures. There are several ceramic nozzles that are cast then fired for strength as well but they are not as common though they are much cheaper to make then graphite. -dag
Mach25 Posted August 4, 2011 Author Posted August 4, 2011 (edited) If you are talking APCP fuel then no, the zinc will melt like butter. Graphite rod is often turned to the nozzle profile as it will not erode at high temperatures. There are several ceramic nozzles that are cast then fired for strength as well but they are not as common though they are much cheaper to make then graphite. -dag I was thinking about Ap with HTPB binders and Aluminium. I think Cstar is 4300 with temp at 3800F...I was just looking for a better way to make seveal without having to turn rod stock. I believe my vulcanizer used for making molds might be useful though. It a vice that presses a 12" disc mold tool set while a heating element heats the top and bottom press plates. Oh well back to Durhams putty I quess! Edited August 5, 2011 by Mach25
Mach25 Posted August 5, 2011 Author Posted August 5, 2011 Also has anyone played around with high density jells used in the screen printing industries as binders? I have actually made some very slow burning propellant from plastisol white, AP and Aluminum. I cured it in my walk in environmental chamber at 350 for about 10 MIN. I had a fuel rich composition and did only a small test so...I know its not condoned to be curing AP... It did set up nicely. I would bet there a star making method here.
dagabu Posted August 5, 2011 Posted August 5, 2011 Also has anyone played around with high density jells used in the screen printing industries as binders? I have actually made some very slow burning propellant from plastisol white, AP and Aluminum. I cured it in my walk in environmental chamber at 350 for about 10 MIN. I had a fuel rich composition and did only a small test so...I know its not condoned to be curing AP... It did set up nicely. I would bet there a star making method here. No, what are the chems in it? -dag
Mach25 Posted August 5, 2011 Author Posted August 5, 2011 (edited) No, what are the chems in it? -dag I believe both are PVC with a plasticizer. The one I used also had some Tio2 to make it opaque. I cured it in a open ended cardboard tube in a controlled environmental chamber at 350. Burned pretty vigorously considering it was low AP content and no other fuel added. Web set up nicely in a 2"X2" segment. Edited August 5, 2011 by Mach25
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