9 replies to this topic

[dave]

does anyone know where to get the above in the uk ?
it is a polyester resin based on styrene used in bonding flares

ive tried a few fibre glass type resin suppliers but they have not heard of it under that name

dave

http://www.ides.com/...56/Laminac-4116

[whoof]

Hi Dave
Iv experimented with polyester, urethane and epoxy resins from my local shop.
They all work, and i saw someone on you tube making rockets using araldite.
Best was Urethane casting resin as it had the lowest viscosity.
Polyester resin used for glassfibre generally has thixotropic thickening agents added.

I believe Polybutaidene is best as rockets using it emit very little smoke although i have not been able to find it over here.

If you want to cast it rather than extrude/presss then about 20% needs to be used which makes it rather an expensive proposition.
Otherwise 3-5% seems adequate as a binder.

Iv recently found a soft urethane rubber which looks very promising but at the moment i have run out of chems.

http://www.thefibreglassshop.co.uk/

Their resin A is very similar to the one you asked about looking at the msds.
They also have neat styrene available which can be used to thin it down.

Edited by snert, 22 June 2011 - 09:45 AM.

[pyrotrev]

Iv recently found a soft urethane rubber which looks very promising but at the moment i have run out of chems.

http://c/

Their resin A is very similar to the one you asked about looking at the msds.

Thanks for the link to the fibreglass shop - where did you find the urethane rubber please?

[whoof]

Thanks for the link to the fibreglass shop - where did you find the urethane rubber please?

Techsil.
A bit dear though and i have not tried it.
Working life may be to short.
I have a set sample i can snail you if you drop me a pm.

[dave]

If you want to cast it rather than extrude/presss then about 20% needs to be used which makes it rather an expensive proposition.
Otherwise 3-5% seems adequate as a binder.

Iv recently found a soft urethane rubber which looks very promising but at the moment i have run out of chems.

http://www.thefibreglassshop.co.uk/

Their resin A is very similar to the one you asked about looking at the msds.
They also have neat styrene available which can be used to thin it down.

hi,
techsil have a lot of products......... which was the soft urethane rubber you had in mind ?

two good sources there, and good resources for reference

i think resins offer an underused resource in certain compositions as binders, maybe not comercially but certainly to provide an alternative to pressing
assuming they burn ok and do not interfere too much.

thanks
dave

[whoof]

hi,
techsil have a lot of products......... which was the soft urethane rubber you had in mind ?

two good sources there, and good resources for reference

i think resins offer an underused resource in certain compositions as binders, maybe not comercially but certainly to provide an alternative to pressing
assuming they burn ok and do not interfere too much.

thanks
dave

F60

Commercialy i think they are too expensive except for specialised uses like flares (waterproof). Rocket propellant (fuel and binder).
I am rather hoping that it will make rocket making easier without the need for really hard ramming. Hitting bp with a hammer is not my idea of fun.

I tried the resin a yesterday, recommended styrene is max 5% which thinned it well.
I also tried 10% which also worked but took longer to set, i think it is slightly softer too.
Hope to try 20% today.
It does get too hot to touch though after the gel stage.
That is as a solid lump though but something to be aware of.
A slower catalyst is needed possibly.
Urethanes and epoxies seem to have lower exotherm but are more expensive.

Edited by snert, 23 June 2011 - 12:17 PM.

[dave]

thanks for that snert,

i think i may have to try some out.

i would be interested to see what kind of compositions you are using it in.
i would not plan on using it at > 5 or10% level

pm me if preferred

im thinking of flare type compositions

sounds like the exotherm is a bit on the hot side though

dave

[pyrotrev]

Another source that might be slightly cheaper than Techsil is resins-online.com (look under casting polyurethanes). They have a couple of PU's (Gel cast 10-A and E003) that look promising if you want something rubbery.

Edited by pyrotrev, 24 June 2011 - 10:58 AM.

[whoof]

Thaks Trev the E003 looks ideal.

i would be interested to see what kind of compositions you are using it in.
im thinking of flare type compositions

sounds like the exotherm is a bit on the hot side though

dave

Comps- none yet, experimentation is neeeded.
First i need to work out the stichiometric ratio of binder to nitrate using an inert filler.

Similar experiments for the other oxidisers although once i get the nitrate right the others should be easier to calculate.

Pyrotrev seems to be taking an interest and he has far more experience than me.
You could try asking him for pointers.
If we are talking specific mixes though i would suggest taking it to the members area at least.

Slower catalysts are available but local guy does not have them.

Edited by snert, 24 June 2011 - 01:39 PM.

[pyrotrev]

Thaks Trev the E003 looks ideal.




Comps- none yet, experimentation is neeeded.
First i need to work out the stichiometric ratio of binder to nitrate using an inert filler.

Similar experiments for the other oxidisers although once i get the nitrate right the others should be easier to calculate.

To work out the right fuel:oxidiser ratio, you really need to have an idea of the chemistry of the particular resin. A few PU's (generally clear ones) have an aliphatic isocyanate which has a lot more hydrogen in it and hence needs more O than one with an aromatic isocyanate. Typical Empirical formulae per unit can vary between C11H20N2O4 and C18H17N2O4 per polymer unit.