5 replies to this topic

[whoof]

Has anyone here know or know of anyone who has experimented with catalytic rubber binders for pyro use please ?
I am refering to this type of stuff used for APCP rocket propellant.
http://aeroconsystem...ubber-92-0.html

Ive been having a play and think there could be good use for it for some pyro.

[Mortartube]

I think Brocks did in the late 60's and early 70's. They did a lot of experimental works, much with resin casting and extrusion, including a screen printed pinwheel. The comp was just printed a a piece of cardboard.

I am sure they used experimental rubberised motors too.

[whoof]

I think Brocks did in the late 60's and early 70's. They did a lot of experimental works, much with resin casting and extrusion, including a screen printed pinwheel. The comp was just printed a a piece of cardboard.

I am sure they used experimental rubberised motors too.

Thanks, i wonder why they stopped.
I dont want to waste a lot of time and chems only to discover some fundamental reason for not using them.

Using inert fillers, mainly charcoal ive managed to mix and cast 12 ice cubes (stars ?) in 5 mins which set in 30 mins.
Also managed to extrude a sasuage of varying diameters using a mastic gun
These look promising for smoke / lances without a tube.

All in a few minutes without the usual mess on the bench.

[Mortartube]

Thanks, i wonder why they stopped.
I dont want to waste a lot of time and chems only to discover some fundamental reason for not using them.

Using inert fillers, mainly charcoal ive managed to mix and cast 12 ice cubes (stars ?) in 5 mins which set in 30 mins.
Also managed to extrude a sasuage of varying diameters using a mastic gun
These look promising for smoke / lances without a tube.

All in a few minutes without the usual mess on the bench.

I think some of it only stopped when Standard bought out Brocks. Brocks had some very ingenious people, who weren't going to work for Standards as they didn't agree with the Standard work philosophy. This is what I was told by a long standing member of the industry. Basically Brocks had some very clever innovative people, whilst Standard were just another company doing the same old thing seems to be the message.

I know Brocks used to use resourcinol resin to cast stars (I have some in a vintage rocket). They poured the mix on a rubber mat. As it began to dry it was scored. When dry the mat was bent to break the mass into little postage stamp like stars.

Resourcinol is expensive now, so I uess that's why it's not used.

Wells still resin cast and extrude their lances.

Here's a pic of the rocket and stars.

http://www.pyrosocie...h__1#entry28661

Edited by Mortartube, 12 June 2011 - 03:14 PM.

[dave]

Thanks, i wonder why they stopped.
I dont want to waste a lot of time and chems only to discover some fundamental reason for not using them.

Using inert fillers, mainly charcoal ive managed to mix and cast 12 ice cubes (stars ?) in 5 mins which set in 30 mins.
Also managed to extrude a sasuage of varying diameters using a mastic gun
These look promising for smoke / lances without a tube.

All in a few minutes without the usual mess on the bench.

where did you get the resins from ?
fancy posting any rough formulations?

dave

[whoof]

where did you get the resins from ?
fancy posting any rough formulations?

dave

Well i was casting some nose cones from commercial urethane 2 part casting resin and made a bit too much so i decided to chuck in some nitrate to see what happened.

Some urethanes are based on HTPB but not all.

This is a fairly hard plastic and takes a blowtorch to get it going but burns well.

I tried a smoke colourant but had too much oxidiser which burnt it out .
Too little Oxidiser you get a black smoky pungent smoke.
I tried a few experiments but found consistency problems and crystals in the bottom of the tins which i think are storage related.

The HTPB used for propellant is much softer and takes fire more easily.
I will not be doing any more tests until i can get a more suitable resin which is proving difficult.