regarding lift amounts

[flamingape]

so because I don't have a mill built yet I really can't do any decent BP lift, as such I have decided to use H3.

 

I was wondering if anyone had a formula or general rule on what amount of H3 pulverone I should use to lift a star bag. My H3 is made with airfloat lump hardwood charcoal and chlorate as fine as flour.

 

 

In return I give you this.

 

green flash (tested for effect)

 

perchlorate 8

zinc 2

[Arthur]

Making things with the wrong compounds simply because you don't have the right tools is dangerous. H3 is a chlorate mix therefore has incompatibilities with sulphur containing compounds like BP.

 

Please walk carefully before you run! Get a good but small mill so that you can make perfect BP before you progress.

[qwezxc12]

I wouldn't go as far as to say the H3 is the "wrong compound"...many people have used it for lift for small (1-1/2" - 3") shells and mines as well as break charges in smaller shells where a more energetic burst charge is needed. Chlorate incompatibilities shouldn't matter if a suitable barrier is used between the lift charge of a mine and the stars, and normal handling cautions are observed. That said, I have no dog in this fight or personal experience using H3 in this application.

 

I'm answering flamingape because his question appeared to be legitimately framed and valid, not a koolbomzdude spoon-feeding exercise.

 

Info gleaned and quoted from rec.pyrotechnics: YMMV!

 

For shells, a starting point would be about 45-50% of normal BP lift qty.

For mines, 75%

 

Probably a smart idea to test with an inert payload first!

 

Not applicable to mines, but an interesting problem reported was that H3 did not seem to burn hot enough (or long enough?) to ignite the cross match on shells. The particular poster found that priming the crossmatch with a layer of H3 paste (H3 w/6% dextrin in water/alcohol) and then a layer of granulated H3 fixed the problem.

 

Search rec.pyrotechnics for additional info. Be safe.

Edited July 30, 2008 by qwezxc12

[flamingape]

Making things with the wrong compounds simply because you don't have the right tools is dangerous. H3 is a chlorate mix therefore has incompatibilities with sulphur containing compounds like BP.

 

Please walk carefully before you run! Get a good but small mill so that you can make perfect BP before you progress.

 

 

you seem to be under the impression that I don't notice that warning everywhere.

 

I knew that as such I will not use sulfur in compositions with it...the amount of time the lift will be in the tube will be somewhat insignificant...on the order of 30-60 seconds.

 

I don't think a paper wrapped lift charge will react quickly enough with paper encapulated stars prepared/dried/stored in a separate room.

 

thank you mr Hard to type name!

I actually tissue touch paper with a sandwiched layer of sulphurless BP and coffee filter touchpaper as my star bags to ensure ignition...also makes some nice sparks on firing

 

I'm assuming the function is as thus?

W= weight of projectile

 

(.1xW).75=Lift amount?

Edited July 30, 2008 by flamingape

[DeepOvertone]

I'm assuming the function is as thus?

W= weight of projectile

 

(.1xW).75=Lift amount?

 

that would be 7.5%

for 75% the formula would be Wx.75=lift ammount.

Edited July 30, 2008 by DeepOvertone

[flamingape]

I thought it was 10% the weight of the projectile for BP pulverone?

plus this

For shells, a starting point would be about 45-50% of normal BP lift qty.

For mines, 75%

so its 75% of 10% of W

 

so .75(.1xW) right?

 

I'm lost

[DeepOvertone]

I misread your post.

 

I thought W=weight of bp propellant. I'm at work so I have to read fast!! So yes then it would be your original formula. or 75% of the black powder propellant. They listed 75% for mines though, not for shells. 40-50% for shells. I'm guessing because of the additional confinement from being a solid shell vs a bunch of loose stars.

[qwezxc12]

I misread your post.

 

I thought W=weight of bp propellant. I'm at work so I have to read fast!! So yes then it would be your original formula. or 75% of the black powder propellant. They listed 75% for mines though, not for shells. 40-50% for shells. I'm guessing because of the additional confinement from being a solid shell vs a bunch of loose stars.

 

That's more what I meant.

 

Example: Shells supposedly require 40-50% of BP equivalent in H3, so if you had a 4in shell that weighed 320g, you'd usually use 1/16 the weight of the shell, or 20g of BP for lift. 50% of this qty = 10g of H3 lift as an equivalent.

 

In a non-piston (bag) mine, I typically use 15% the weight of my stars as lift. 75% of that = 11.25% of the weight of the stars. Again, YMMV.

 

I'd recommend a test with an inert payload if you're trying shells. If you are going for mines, start on the low side, say 7-8% the weight of the stars and work your way up until you're happy with the lift and dispersal of the stars.