Potasium perchlorate lift charge?

[mark]

Hey all. Im think of buying some little mini mortars for shooting m80s. Would a mix of 50-50 PP to AL work, or would it burst the cardboard launch tube. How about 50 pp, 25 al, 25 powdered sugar? Thanks.

[Aaron-V2.0]

I know of a Potassium Perchlorate based bursting charge but no lift charge. But I'd imagine the burst charge would work just as good. Ratio is 70/12/28 KClO4/Sulfur/Charcoal with a little bit of dextrin.

<a href="http://krimzonpyro.com/rat/compositions/PFP-database.zip" target="_blank">PFP Database</a>

That is the PFP Database, it contains about 10 different mixes for a single mixture. Great info on Black Powder, Flash and some thermite mixes in addition to the many star, fountain, smoke and rocket mixes.

[mr.evil]

i absolutely wouldn't lift anything with (slow) flashpowder.

use KP (blackpowder on KClO4 based instead of KNO3) or just the good old granulated BP :)

[NickSG]

whats wrong with good ol black powder? It works fine. I suppose you could use flash powder, but i wouldnt waste my aluminum on it, and risk an explosion.

[ALENGOSVIG1]

Yeah BP is the best choice for lift charges. It's not too strong and it's easy to prepare. Unless your using metal mortars and your worried about sulphur ruining the metal.

Another good left charge is perchlorate/sodium benzoate buts it a bit too powerful.

[Nika452]

My experience with perchlorate black powder is that it usually requires far less effort than nitrate black powder to get a comparable burn rate. Grinding the constituents together in a mortar may be enough for a lifting powder.
This is well if you don't have a ball mill, since potassium perchlorate is so much less soluble that potassium nitrate. I suspect that the precipitation method might not work as well.

I think that whistle mix might be too fast. What would happen if the oxidiser was partially potassium nitrate instead? It would probably slow the burn rate, yes?

Edit--typo

<small>[ March 16, 2003, 02:42 AM: Message edited by: Nika452 ]</small>

[NickSG]

Nika: I A 35/35/30 mix of nitrate, perchlorate, and benzoate should work. Altogether replacing the perchlorate with nitrate might work, i have no idea. I was thinking of testing per/chlorate and sugar as a possible lift charge, as soon as my chemicals come in.

[Nika452]

I have been using a potassium perchlorate sugar mix for rockets, and I have noticed that burn rate seems to increase quite a lot with pressure.
I do not think it would make a very good lift charge; for it probably burns too slowly. A pile in the open burns fairly tamely--slower, I think, than a similar mixture with potassium chlorate. I don't know if a short firing tube would allow enough pressure to build up for the burn rate to increase enough to launch a projectile effectively.