Exactly DH, non toxic Propylene Glycol was my thoughts, available at auto
parts stores as antifreeze coolant and in my cars radiators.
Theoretically water under pressure with a calibrated relief valve so the
temp can never exceed a safe temp. Depending on the grade of asphalt no
relief valve just melt/mix at the boiling point of pure water. I tested my
asphalt sample at the BP of water, 219F at my elevation, and it was at a
workable viscosity. I don't have a Haake viscometer like at Edwards but it
was about like R-45 at RT maybe a bit thinner.
K
On Wed, Jul 8, 2020 at 4:32 PM DH Barr <dhbarr@xxxxxxxxx> wrote:
For the amateur with a double boiler and appropriate ratios of alcohol,
water, and glycol; one should be able to precisely target arbitrary
temperatures across a fairly wide range ( boiling point of pure alcohol
through boiling point of pure glycol ).
On Wednesday, July 8, 2020, Troy Prideaux <troy@xxxxxxxxxxxxxxxxxxxxx>
wrote:
IIRC it's a technique also employed for gelatine processing in capsulewindow
manufacture for drugs. I vaguely recall gelatine has quite a narrow
of temperature where it will stay liquid - around 60deg C orthereabouts; so
a heating jacket is employed using steam, but due to the lowertemperature,
its pressure is reduced to near vacuum to ensure boiling and uniformsteam
dispersion throughout the heating jacket.]
Speaking of vacuums, you can also utilise a partial or full vacuum to
increase the safety margin of propellant processing utilising elevated
temperatures ie. it's much harder to ignite propellants under vacuum
conditions.
Troy
-----Original Message-----
From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx
Onyou
Behalf Of Henry Spencer
Sent: Thursday, 9 July 2020 7:19 AM
To: Arocket List <arocket@xxxxxxxxxxxxx>
Subject: [AR] Re: Amateur thermoplastic binder solids
On Wed, 8 Jul 2020, William Claybaugh wrote:
My sources say AP ignites a little above 400 degrees F so a binder
that forms a low viscosity fluid at around the BP of water will in
theory work fine if there is no possibility of hot spots.
If you can find something that works *at* the boiling point of water,
canfor
use steam heat (with a steam source that heats the water, not the
steam) to ensure it just can't go any hotter.
(This technique is, or was -- my info may be out of date -- widespread
fillingstirring.
munitions with TNT, which is a fairly-stable liquid at 100degC.
That helpful property is one reason why TNT became so popular.)
If I were going in that direction I would want to automate the mixing
rather than stand over an open pot of hot binder, AP, and Al,
from a
If one must pre-fix fuel and oxidizer :-), especially hot, doing it
distance
makes a whole lot of sense.
Henry