roger's pyrotechnic offerings and experiments

[enanthate]

Just tested a new comp containing dragon eggs. Cant wait to see this one in a shell! Raining slowly to the ground from a soft break i imagine.

http://youtu.be/l5BzLnynIAE

[Mumbles]

That's a good idea. I've never thought of adding DE to glitters before. It sort of tricks you into thinking there are a lot more DE in there. I bet one of those "sizzling" type glitters or streamers with coarse MgAl would add to the effect.

[rogeryermaw]

 

 

Edited January 1, 2015 by rogeryermaw

[rogeryermaw]

Edited January 1, 2015 by rogeryermaw

[rogeryermaw]

 

 

different cameras interpret colors VERY differently...

Edited January 1, 2015 by rogeryermaw

[Niladmirari]

Excellent test.

 

I think you have too fine grinding of coal. Therefore D1 glitter burns too quickly. If you increase the size of the coal particles, the effect will be longer.

Or small stars in shells?..

 

What is the composition of the comet on the shells (rising effect)?

Edited January 1, 2015 by Niladmirari

[rogeryermaw]

Thank you!

 

It may be too fine charcoal but i think it more my choice of wood. I should be using a slower burning hardwood but i used pine. The. 2.5 shells used about 8mm stars and the 4" used about 11mm.

 

The rising comets were 40% KP, 38% milled pine cc, 12% 30-100 mesh Ti, 10% red gum. Acetone solvent and pumped 1/2" x 1/2" topped with a bit of b.p. to prevent seizing or galling the pump.

Edited January 1, 2015 by rogeryermaw

[rogeryermaw]

on the block there are two piles of d.e. one (right) is maybe cut 15 or 16 1mm eggs. left is over 150. mostly they were scored but unbroken. anyway i screwed up the video of the small pile but it did not react. as you can see it's still there. the large pile however:

 

http://youtu.be/r51c19AA1mc

 

this is peculiar as larger eggs will typically break into smaller pieces instead of going all at once. thoughts?

[enanthate]

Whats up with the insane delay?

How do you make them go off before they hit the ground?

 

Could it be that one egg explodes and destroys the rest? Like you say, its kinda weird.

Whats up with the insane delay?

How do you make them go off before they hit the ground?

 

Could it be that one egg explodes and destroys the rest? Like you say, its kinda weird.

[rogeryermaw]

enan i doubt these eggs would be usable

 

this is the "gold twinkler" + dextrin i found on cannon fuse website. its listed just below the Winokur formulas.

 

18 KNO3

03 S

03 Al

03 Sb2S3

03 lampblack

04 Na2C2O4

says to bind with water but shows no binder. added 04% dextrin

 

[rogeryermaw]

so...i started fooling around with Shimizu's strobe formulas and have come to the conclusion that i need much more coarse magnesium. there does not seem to be a plethora of good sources for mesh in the 50-100 range. anyone care to share a source or can help point me in the right direction. you can p.m. me if you are uncomfortable publicly citing suppliers.

 

i see most people say that the a.p. strobes are superior in some way but the nitrate strobes, with less predictable in their frequency, seem to have much better color depth. thoughts? opinions?

Edited January 21, 2015 by rogeryermaw

[dagabu]

I'm not a fan of Shimizu's strobe, I like TR's strobe much better, MgAl in the comp is pretty forgiving and just sieving it can weed out the small bits that seem to speed up the strobe.

[Mumbles]

I think you're confusing strobes here Dave. The TR formula is a white nitrate based strobes. Rodger seems to be talking about the AP based colored strobes that were ubiquitous for a long time until the publishing of some functional colored nitrate strobes. The AP ones are still are king as far as frequency regularity.

 

I like nitrate based strobes better. More because they're still a somewhat unexplored territory and there is a lot of landscape for tinkering. If I wanted something functional off the shelf, I'd go with AP for now though. I do believe that nitrate strobes will become much more popular, especially in shells, in the coming decade though. There are still intricacies to work out.

[dagabu]

I think you're confusing strobes here Dave. The TR formula is a white nitrate based strobes. Rodger seems to be talking about the AP based colored strobes that were ubiquitous for a long time until the publishing of some functional colored nitrate strobes. The AP ones are still are king as far as frequency regularity.

 

I like nitrate based strobes better. More because they're still a somewhat unexplored territory and there is a lot of landscape for tinkering. If I wanted something functional off the shelf, I'd go with AP for now though. I do believe that nitrate strobes will become much more popular, especially in shells, in the coming decade though. There are still intricacies to work out.

 

Yes, indeed, I did not go back to look at the base for the strobe. In any case though, I like the TR strobe better is stars due to the ease of manufacturing if nothing else.

[rogeryermaw]

so i've been working on my glitters. almost there.

 

[patsroom]

IMHO the glitter looked good to me ..............Pat

[rogeryermaw]

thank you nt8 for sharing this. don't think my camera captured the color well...

 

 

Shimizu green strobe (lightly modified).

 

[stix]

so i've been working on my glitters. almost there.

 

 

Very nice - what glitter comp is it?

[enanthate]

Love those strobes, wish I had the balls and/or knowledge to mess with AP.

 

Shot 7 shells today, none with booster. Very low ignition rate, we're talking 10%. We're also talking about tiger tails. What the fck?

The last shell had pumped stars with 100% ignition rate, the rolled ones pretty much failed all together. I don't prime my tigertails, the only possibility I see here is the surface. They were not "glassy" smooth, and not dusty either. Something in between. Where am I going wrong on this?

[rogeryermaw]

thank you stix. that glitter is from post 110. i found it on cannonfuse.com. unfortunately i don't have anyone to give credit to...

 

http://www.amateurpyro.com/forums/topic/10192-rogers-pyrotechnic-offerings-and-experiments/?p=138545

 

enan, if i had to guess, i'd say it was possible you mis-measured some chemical in your formula. or mistakenly substituted something. i've done that before. as far as priming, most black powder stars do ok without extreme priming but i prime every star every time. they behave differently in stargun/mine/shell so i just don't take chances. takes me too damn long to paste to deal with blind stars.

[stix]

Thanks. I did actually see that previous post - the effect is much more spectacular in post #115, beautiful.

 

btw. I'm a bit confused about Sb2S3. The same chemical name is used for Antimony sulfide AND Antimony trisulfide (chinese needle)

 

Ok, I just found the same comp on pyrodata - http://pyrodata.com/compositions/Golden-twinkler-star

It refers to Antimony trisulfide.

 

Also, I assume that's Al powder, not flake?

 

Cheers.

[rogeryermaw]

Yessir i used 300 mesh al.

[stix]

Thanks for the info rogeryermaw.

 

I could only order 200 mesh - I hope that will still work.

 

Cheers.

[rogeryermaw]

it should work fine. i doubt you will notice a big difference in performance. at 200 mesh, your powder will still contian a good percentage of finer material. let me know how it holds up if you get a chance to try it out.

[FlaMtnBkr]

Did you ever figure out your Dragon eggs? I can explain what is going on if you want. But basically your MgAl is a little to big. When the particles are bigger it makes them smolder longer and sometimes it is so big that glow red but never pop. It also makes it all get up to heat and pop at once. You can use the same MgAl and replace a portion with finer material if you want to use what you have in dragon eggs. Or you can replace it all with a finer mesh but not too much smaller. You can probably also add a few percent of straight magnesium if you have it. The magnesium is used in the smolder phase and as the MgAl melts it adds more magnesium and adding magnesium can accomplish the same thing as finer mesh MgAl. The finer mesh melts quicker and gets the magnesium into the reaction quicker.

 

The aluminum is consumed in the flash phase or the pop. So too fine MgAl gets too much magnesium in the melt and cause small pockets of comp to pop which results in a lot of small pops from one egg. Usually the small pops blow off the lit part of the egg and the bulk goes unreacted and is a waste. This is it is going off in one mass because the particles are too big so the entire mass is able to get going and when it finally pops it all pops.

 

My 200 mesh MgAl works well in my 3-4 mm eggs using the 37.5/37.5/25 formula. But it looks like it is probably -200 mesh and contains a lot of fines. That's what works for me and I like that formula the best of all that I have tried which is about all the published formulas I have come across. Some people get them working the first time and others have nothing but problems but it all comes down to the mesh size of your metal. And you can tune them pretty easy by using a different mesh or by replacing a portion with finer or coarser material. Since 100, 200, and 325 mesh are the common sizes, changing all of the material can be too big of a jump. Just depends on what you have available. If you try adding straight magnesium I would start by adding 2-3% to start. MgAl is also quite friable and you can grind it finer fairly easily in a mortar and pestle. You might be able to add more MgAl to get more magnesium in the melt quicker but I don't think I've ever tried that. I've experimented with DE a lot and don't remember it all. When you are tuning them it helps to right down exactly what you did so you can repeat it with your chemicals but that's a good thing to do anytime you are experimenting as I'm sure you know.

 

Hope that all makes sense.