I think it's AP less than 15 microns that is considered an explosive by the
ATF.
On Wed, Jul 8, 2020 at 9:55 PM roxanna Mason <rocketmaster.ken@xxxxxxxxx>
wrote:
Isn't 25u is conceded an explosive by the ATF?
On Wed, Jul 8, 2020 at 8:46 PM Troy Prideaux <troy@xxxxxxxxxxxxxxxxxxxxx>
wrote:
Yes Tepanol, but I was referring to HTPB binders – duh, apologies for the
confusion.
Regarding finer micron AP: this from our former China Lake resident:
“The standard practice for grinding fine AP around here is to basically
put 100 micron AP into a venturi chamber and blow a buttload of air through
said chamber.”
Troy
*From:* arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx]
*On Behalf Of *Tyler Adkison
*Sent:* Thursday, 9 July 2020 1:32 PM
*To:* arocket@xxxxxxxxxxxxx
*Subject:* [AR] Re: FW: 2.6004.pdf
Good to know! I assume by bonding agent you mean Tepanol? If so, how did
you apply it? Did you mix it in with the dry AP or the asphalt, as I would
imagine the heat would somewhat neutralize it.
On Wed, Jul 8, 2020 at 8:23 PM Troy Prideaux <troy@xxxxxxxxxxxxxxxxxxxxx>
wrote:
I’ve used a fair bit of 400micron (maybe 50-100 motors worth) in the 90s
and can’t recall any noticeable runaway exponents with or without bonding
agents. What is noticeable is the susceptibility for the large particles to
shear off on the surface if rubbed with a finger or something else
(especially with no bonding agent) but the internal ballistics were always
pretty well behaved for me at least. Most of the motors were run at 500ish
Psi but some were run up to 1000. I found the 400 micron stuff was always
the most pourable of all the combinations.
Troy
*From:* arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx]
*On Behalf Of *Tyler Adkison
*Sent:* Thursday, 9 July 2020 12:52 PM
*To:* arocket@xxxxxxxxxxxxx
*Subject:* [AR] Re: FW: 2.6004.pdf
I think the 25 micron AP is a bit of a sticking point, both literally and
figuratively. I've never worked with asphalt composite motors before, but
from my research experience, 200/25 is excellent modality, but 25 micron AP
is incredibly hard and expensive to find. I suspect that overall properties
would be considerably less ideal (possibly unable to be poured and a slower
burn rate) if you tried to sub it for 90 micron instead. Trying to use a
400/90 blend may work, but I'd expect that without the ability to
effectively use Tepanol, the 400 would shear and thus the exponent would be
brutal. That said, thank you for sharing and it is very interesting indeed.
-Tyler
On Wed, Jul 8, 2020 at 7:20 PM ken mason <laserpro1234@xxxxxxxxx> wrote:
I got my log book from work at Edwards AFB Rocket Lab circa 1987-89 and
the basic formula is as follows:
15% - Binder of which 70% is AC-3150 asphalt,15% Kraton D1107 15%
Rohm/Haas B-72 Acryloid
18% - 6 micron Al powder (MDX-65)
45% - 200 Micron AP
22% - 25 Micron AP
100% - Total
Pot Temp 255-260F
Dec. 11th 1987
Ken
On Wed, Jul 8, 2020 at 5:22 PM 1bcjolly <1bcjolly@xxxxxxxxxxxxx> wrote:
Ken Mason posted an article that was in 2 parts. Here is the article
in one attachment. Hope this is helpful.
Barry
Sent from my Sprint Tablet.
-------- Original message --------
From: 1bcjolly <1bcjolly@xxxxxxxxxxxxx>
Date: 7/8/20 20:17 (GMT-05:00)
To: 1bcjolly@xxxxxxxxxxxxx
Subject: 2.6004.pdf
Sent from my Sprint Tablet.