Mombu 2009-08-06 16:20:54
I read that the Kassam rockets are fueled by a combination of sugar and
Anyone know how good a fuel it is? ISP numbers?
How does it compare to other solid fuels?
Have amateur rocket builders used this fuel in the past?
Seems like a cheap way to make a solid rocket.
Delt0r 2009-08-06 16:21:05
Google is your friend. I have used this and other amatures (not this
group) have too. It can be inconsitant and its ISP downright stinks.
But its fun and cheap providing you learn your chemistry and safty
Mombu 2009-08-06 16:21:13
I think the rocket is a bit more complex than that, as i have built
Sugar rockets and i am pretty sure we were never going to be able to
launch any type of heavy payload like that anywhere near the range that
the kassam rockets have. but i did see something about them using
fertilizer, sugar diesel fuel and something else. i will ask some arab
firends of mine there probably is a arabic website with instructions on
how to make them.
Mombu 2009-08-06 16:21:30
kassam Rockets are a bit more complex than that, diesel is actually
added to the fuel, but they do not release the formula as they are
worried that isreal will make sure they cannot get key componets if
they do. i have built sugar rockets before and there is no way you
could use it to launch war heads that distance.
Cray74 2009-08-06 16:21:32
Google delivers instant hits on sugar/potassium nitrate model rocket
John 2009-08-06 16:21:52
When I was a kid in the early 70’s I had a paperback book that was
called “A guide to amateur rocketry” that had plans for rockets that
used a “carmel candy” propellent based on sugar/Potassium Nitrate. You
would melt it in an oven and pour the mix into the rocket casing. The
rockets were about 4′ long and describes as capable of reaching
ISP numbers after all this time. I haven’t seen the book in at least
20 years, saw it listed on bookfinder for $48
John Hartley www.hotmoon.org firstname.lastname@example.org wrote:
Mike swift 2009-08-06 16:21:54
Yes KNO3 and sugar has been used as an amateur rocket propellent. It is
also called caramel candy propellent as the sugar is first melted then
the KNO3 added slowly and mixed. The propellent is then cast into the
motor casing or a mold. It is not used today because of several
disadvantages. (1) It provides little improvement over black powder as
far as ISP. (2) You have to heat it to the melting point of the sugar
to cast it. (3) It is brittle, and grains larger than one or two inches
tend to crack, and the rocket CATOs on firing.
Two things only the people anxiously desire, bread and circuses.
Decimus Junius Juvenalls
Jim logajan 2009-08-06 16:22:32
The book you are thinking of is probably “Rocket Manual for Amateurs” by
Capt. Bertrand R. Brinley; (C) 1960. (No ISBN number.) I read that book
back in the early 70’s too. The copy I read went missing sometime in the
last few decades, so a year ago I managed to buy a used copy online via one
of the used book sellers who sell through Amazon.com.
Brinley did not give any ISP numbers for the “caramel candy” propellant but
did specify a theoretical ISP of 46 sec for zinc/sulfur at a chamber
pressure of 1000 PSI. However, that was after a correction factor of 50% –
the uncorrected ISP would have been 92 sec. (The stated reason for the
correction factor was because one of the exhaust products, zinc sulfide,
has a heat sublimation at the flame temperature, so that it would not
expand to produce thrust. But Brinley pointed out that at that time it
wasn’t clear to what extent that happened, if at all.)