Cotronics makes a relatively inexpensive graphite adhesive/sealant that’s good
to well over 5000 F. Taper the OD of the graphite throat and the ID of the
nozzle convergent section to for a positive taper lock. Coat both surfaces,
drop it in and heat cure it. Standard industrial practice.
Best.
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
<http://www.cesaronitech.com/> http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx] On ;
Behalf Of BrianK ABQ
Sent: Friday, November 4, 2016 6:30 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Alternate nozzle materials for APCP propellant
Gents,
A favorite topic of mine. Some ideas:
1. I saw one nozzle that was made from a hunk of phenolic (?) cloth tube with a
graphite throat insert. It certainly seemed like the best of both worlds.
2. Graphite does dump so much heat to the casing. The idea mentioned of an
insulating band between it and the wall is worth looking at.
3. I just bought some carbon fiber washers that might make nice throat inserts.
They come in all sorts of sizes. The ones I got were 28mm OD, 15mm hole, 2.5mm
thick. Here's a link:
http://www.ebay.com/itm/201625351883?_trksid=p2060353.m2749.l2649 ;
<http://www.ebay.com/itm/201625351883?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT>
&ssPageName=STRK%3AMEBIDX%3AIT
4. Firefox provides some nice insulation material. My favorite is their
graphite impregnated cloth. I use it a lot; line bulkheads, make custom
casting/liner tubes for propellant grains, etc. I'd thought of trying to make
nozzles with the carbon cloth as the main element. Haven't moved past the
thought stage yet.
On another topic. I could really use a strand burner and am not having much
luck making one. Does anyone know of one that might be for sale?Thanks.
Cheers,
Brian
On Fri, Nov 4, 2016 at 12:45 PM, Terry McCreary <tmccreary@xxxxxxxxxxxxxxx
<mailto:tmccreary@xxxxxxxxxxxxxxx> > wrote:
Hi John,
Years ago I molded small nozzles using Firefox's carbospheres and Weldwood
phenolic adhesive. They worked well enough to warrant further attempts. They
did erode somewhat, and the adhesive cured rather quickly and shrank
significantly; they should be cured under pressure to minimize that problem.
Weldwood apparently isn't available anymore but Cascophen seems to be the same
sort of product:
http://www.aircraftspruce.com/catalog/wppages/cascophen.php
Best -- Terry
On 11/4/2016 11:34 AM, John Lyngdal wrote:
Looking at alternate materials for a long burn motor design that have lower
thermal conductivity and heat capacity as compared to graphite. Right now I'm
considering machinable ceramics, BN, and perhaps molded alumina. Any personal
experience or publication links would be most welcome.
John
--
Dr. Terry McCreary
Professor of Chemistry
Murray State University
Murray KY 42071
