6 replies to this topic

[chrissw]

Back in my schooldays (the good old days when sodium chlorate was as pure as the lord intended and fire depressants were no-where to be seen) I also used to buy stuff called "anhydrous ammonium sulphate" from the same h/w store. It was packed just like sodium chlorate and sold for about the same cost and the odd thing about it was that if you mixed it with sugar instead of sodium chlorate it used to burn just as fiercely but with a white flame instead of the usual sodium yellow. I know that the usual ammonium sulphate crystals (the dirty brown stuff) does nothing like this and I was curious if anyone out there could shed some light on what this stuff was (it was sold as fertiliser i think)

[Richard H]

I think your right, I believe it is used as a fertiliser. I once noticed some at a garden centre (however it was in crystal form and rather damp).

[chrissw]

The stuff you get these days is in the form of dirty brown crystals a bit like brown sugar and often does feel like it is a bit damp, the stuff I used to get hold of (and we are talking late sixties here!) was dry, white, crystalline and a bit like common salt in appearance

[Nick]

The only sulphate that I've ever had success with as an oxidiser in pyro is plaster of paris (anhydrous calcium sulphate), with Al powder from resin suppliers. You can cast it just like plaster, and then dry it in the oven, to form little stars or whatever, or leave it loose and dry and it acts as a low-powered flash powder.

Might it have been ammonium persulphate? That is a powerful oxidiser, although I didn't think it would work in pyro, it's generally used in chemistry.

[Rhodri]

It's also interesting to note that plaster of Paris is also used in conjunction with am. perchlorate to create strobe comps.

[zanes]

anhydryous means without water (none at all)

you can heat copper sulphate to make anhydryous copper sulphate, so you might be able to do the same with this.

I believe it is called 'dihydrate' in the states, bernie can you confirm?

ps. I found a new supplier in the states, looks promising (will keep you informed)
also found a website on how to synthesiss some chemicals ( and no a.c. crap either.
I love america (sometimes)
[Edited on 18-7-2003 by zanes]

[Edited on 18-7-2003 by zanes]

[chrissw]

I thought it could have been ammonium persulphate so I bought some from Maplins in the form of Printed Circuit Board Etchant (an alternative to ferric chloride) and tried mixing a bit with an equal amount of sugar but it wouldn't do anything even when blasted with my gas blowtorch