11 replies to this topic

[dave]

has anyone used the above resin (cascamite powder) in small percentages as a star binder and if so is it any use ? i guess low levels only required to minimise ignitability issues of a hard mass.
any chemical /stability issues in any compositins.

dave

[dave]

has anyone used the above resin (cascamite powder) in small percentages as a star binder and if so is it any use ? i guess low levels only required to minimise ignitability issues of a hard mass.
any chemical /stability issues in any compositins.

dave

well that was a popular post...i did check the archives before posting , think icarus may have been using it but no reply yet from a pm

dave

[Mortartube]

I have never used it as a binder, but it makes damned good tubes.

[Mortartube]

Resorcinol resin would be much better (Cascophen), it's what Brocks uused for star binding. Their rocket star mix was mixed with resorcinol resin and poured in a thin layer onto a rubber mat that had a slightly raised grid pattern (as far as I have been told). When dry the mat was flexed and the stars broke into thin regular squares.

[Bub]

Resorcinol resin would be much better (Cascophen), it's what Brocks uused for star binding. Their rocket star mix was mixed with resorcinol resin and poured in a thin layer onto a rubber mat that had a slightly raised grid pattern (as far as I have been told). When dry the mat was flexed and the stars broke into thin regular squares.

This is quite correct, resorcinol resin is an excellent binder. Especially when used in large comets as no water gets into the composition and it therefore dries very hard in a short space of time (as it's a chemical set rather than drying).

You would need to play around with the formulations somewhat to compensate for the binder being added to the mix though ...

No more waiting for a month to dry a 2" comet - you can get them done in 24 hours using the resin.

-=B=-

[Arthur Brown]

http://www.pyrosocie...?showtopic=3589

Has discussed this topic recently and found some good results

[dr thrust]

may i ask were one can procure cascophen resin?

[dave]

[quote name='Mortartube' date='Mar 1 2008, 12:08 AM' post='43050']
Resorcinol resin would be much better (Cascophen), it's what Brocks uused for star binding. Their rocket star mix was mixed with resorcinol resin and poured in a thin layer onto a rubber mat that had a slightly raised grid pattern (as far as I have been told). When dry the mat was flexed and the stars broke into thin regular squares.

i just got some from phil, haven't had time to use any yet though.........sounds promising..........always interested in new "old" ideas (re above brocks method)

thanks......................dave]

[Arthur Brown]

Cooperman did a bulk buy a little while ago. see what he has left. See what he knows about processing with it.

So far all I have heard is very good!

[Mortartube]

Some yachts chandlers will stock Cascophen resin as it is ideal for boatbuilding.

[pyrotrev]

If you can maintain the temperature reasonably warm (BUT WATCH OUT FOR THE POSSIBLE INTERNAL TEMPERATURE RISE DUE TO THE REACTION EXOTHERM IN BIG STARS!!!) You can get resorcinol resin curing in a lot less than 24 hours; I've had stuff ready to test by the night of the same day I've pumped them To get back to the subject of urea/formaldehyde resin, the stuff i've seen needs mixing with water to form a paste, with any of the problems that it might cause during drying. I also suspect it will not give quite such a good burn rate as phenol or resorcinol based resins, thoug I've not tested it.

Edited by pyrotrev, 01 March 2008 - 07:12 PM.

[cooperman435]

Yes as Pyrotrev says Ive had 2" comets pumped that morning hardened and ready to fire by the same night. Ive not found the reaction to be exothermic at that size and have had to place them in a warm place to aid quick drying but 4 or 6 hours is about average.