5 replies to this topic

[pyrotrev]

As I had some excess resorcinol adhesive mixed last night, thought it was a shame to waste it and converted it into the following fuel:

AP 80
Resorcinol resin (cured mass) 15
Atomised Al -250 5
copper oxychloride (+2 addnl)

in a little 1/2 tube went really well until the tube popped - but it was a bit of a wimpy affair anyway. If anyone else wants to experiment with this do be careful with shrinkage due to the water content of some resorcinol adhesives.

[dr thrust]

how long before shrinkage occurs?

[pyrotrev]

how long before shrinkage occurs?

These adhesives seem to cure in 2 phases. Firstly it hardens - anywhere between 20mins and a few hours depending on temperature - and then it gradually loses water and shrinks a little. How long this takes depends on section thickness, temperature and ventilation, the only figures I can offer are for 25mm diameter comets which took about 12 hours at 55....60 deg C.

BTW, obviously worth using a resin system that contains as little water as possible to start with, i.e one with a powder rather than liquid hardener.

Edited by pyrotrev, 23 January 2010 - 02:14 PM.

[icarus]

when the recorcinol and catylist have been mixed you can add large volumes of icy cold acetone from the fridge well shaken in a disposable container this watery liquid is easy to mix into dried fuel/ oxidiser mixes in a mixing bowl with a wooden spoon. Cast fuel pellets are placed in the warm the acetone evaporates off not enviromentally friendly and inflammable vapour but for small scale well mixed fuel pellets or stars superb

[dave]

when the recorcinol and catylist have been mixed you can add large volumes of icy cold acetone from the fridge well shaken in a disposable container this watery liquid is easy to mix into dried fuel/ oxidiser mixes in a mixing bowl with a wooden spoon. Cast fuel pellets are placed in the warm the acetone evaporates off not enviromentally friendly and inflammable vapour but for small scale well mixed fuel pellets or stars superb

sounds a good idea !........lower resin viscosity= more even distribution in the mix.
not sure why it has to be ice cold ? but as i have not tried it, i cant comment

dave321

[digger]

sounds a good idea !........lower resin viscosity= more even distribution in the mix.
not sure why it has to be ice cold ? but as i have not tried it, i cant comment

dave321

I guess to reduce evaporation and increase the working time of the resin.