What did you do today in pyro?

[dagabu]

" A sharp knife with a thin blade..."

 

The real trick is JUST what Mum mentioned, use less moisture and leave it somewhat dry when loafing. Here is a picture of a loaf from the day before that did NOT turn out so well, I over shot the moisture by a few GRAMS!!! Its that sensitive with SGRS. This loaf had the consistency of roofing tar and was nearly impossible to cut. The extra comp I reserved would not mix in to the comp so beware of adding water!!

 

[memo]

I never have used a loaf box to make cut stars, sure looks like the way to go.

 

memo

[Mumbles]

I can never decide if I love or hate SGRS for cutting stars. For what it's worth, if you actually keep adding water it then will loosen up a bit and start mixing with itself again. It's fairly soft at this point though. It's fine for a patty, but probably too wet for a loaf box.

 

It should be noted that the scored pattern on top of the loaf in Dag's pictures is made by lightly pressing a screen into them. This trick has been popularized by Paul Moulder. You can also make a makeshift loaf box out of disposable Glad plastic containers if you want to try it out before building one. The edges are rounded, but it doesn't make much of a difference in the long run.

 

The one thing about loaf boxes that isn't entirely obvious is that the box determines the batch size, you don't. I've often thought about making spacers or inserts for a loaf box to allow some variability in batch size.

 

Do you have any taper on your box Dag, or does the loaf just slide right out?

[dagabu]

Hmmmm, I changed the loaf size by adding less comp to the box. I must be missing part of what you mean.

 

Nope, no taper at all, just square joinery. I used to fold up a single sheet of 70 pound kraft to line the box but changed that to Ned Gorski's two strip method. Just lift the box and the loaf stays put.

 

The loaf just lifts off the bottom paper strip and allows for tipping it on the side to remove the other strip. EZPZ.

[AzoMittle]

Dear pyro diary, today was a busy day, I:

 

• Converted 5lbs of corn starch to dextrin.
• Dichromated the small remainder of magnesium and magnalium I had in storage.
• Made a batch of 1/2" Spanish Fuchsia, parlon bound. Primed with (dextrin bound) monocapa, that's drying now but will need a second layer. Planning on throwing a glitter over top of that and then dusting with BP. Basically my usual MO for this year and last is: Dragon egg cores --> Mg Color --> Monocapa --> Charcoal/Al glitter --> BP. Getting better at them but still not exactly how I want it, mostly need to dial in the colors/find the right shade and burn rate (read: slower so I can use a thinner layer). I'd also like to be get a dark relay for ghost shells working, need a good formula though.
• Finished about 10' of black match, just as a test. I've had nothing but bad luck with making it in the past. This time I: tried unwinding the string first, binding with gum arabic, used a 2x4 and bucket to beat the slurry into the string (with both a pre-soak and post-soak), then dragged it through some meal to coat. It still didn't actually get into the cotton string, I cut into it and saw black around white. Damn the stuff, I'll pay for commercial QM and e-match, two things not worth the trouble of making it feels.
• Pumped a small batch of 3/4" x 1" Willow to Blue crossettes, still need to fill the cavities and paste them. Same with the 2.5" crossettes.
• Mixed up a batch of Tiger Tail with +7.5% Titanium turnings (from the member who was selling them on here, nice looking stuff). Then I realized my scale wasn't reading accurately/consistent, what should have been a 2kg batch ended up at 2.4kg. I rammed three 2.5" x 1" comets, waiting for them to dry so I can test them and make sure they actually burn, if not going to go back and add some oxidizer to the remainder (I had a gut feeling of "this seems like an awful lot of charcoal for TT..." while weighing it out). My pic isn't near as pretty as Dag's but here ya go: http://i.imgur.com/dGxXCWi.jpg
• Coated (what felt like) a metric buttload of hulls 4:1. All hail 3M for giving us the mighty respirator which wards away the evil black boogers!

[Mouse]

Maybe it's just my busted ass Irish Scottish nose but has anyone actually found a respirator that works???

[dagabu]

I use the 3M 5200 but proper fitting is essential. They come in small, medium and large. You may have a medium....

[starxplor]

Maybe it's just my busted ass Irish Scottish nose but has anyone actually found a respirator that works???

https://www.amazon.com/Advantage%C2%AE-3000-Full-Face-Respirator/dp/B0041U7V5W

 

This is what I have, my local grainger let me try the med and lg version for sizing. It has worked great keeping charcoal and bp out of my nose.

[Mouse]

Cheers for the response guys! Starting to think full face is the way to go I've tried a lot of different models in my line of work but they all leak on one side of my nose!! Hehe pretty sure I'm already using LARGE!!!

[AzoMittle]

Late to the party but FWIW things like facial hair/long bangs, scars, dental work, and weight gain/loss can interfere with a respirator. Everyone has a unique facial shape too.

 

You mention that you use a respirator as part of your line of work, if you are in the US and are required to use a respirator for work then your employer is required to both provide an adequate one as well as schedule a fitting and testing with OSHA, there are probably similar laws in other countries. I believe you can also independently schedule a fitting test with OSHA on your own, and there should be private companies who also do it, basically they have you try on a bunch of different respirators and pump an irritant (usually a bitter gas) in and ask if you can smell it or not. We're only given one set of lungs, keep them working, good luck.

Edited September 20, 2016 by AzoMittle

[starxplor]

Cheers for the response guys! Starting to think full face is the way to go I've tried a lot of different models in my line of work but they all leak on one side of my nose!! Hehe pretty sure I'm already using LARGE!!!

 

Yes, the full face ones often fit better because they fit around the whole face which has less variation(still can be unable to find one with a good fit).

 

Also, the full faces ones protect your eyes from light powders like airfloat charcoal, sweat running down your forehead, and accidentally touching your face(eyes) with dirty hands.

 

All around, I am very happy to have the full face one.

[Mouse]

Strangely enough azo I've done the irritant tests and even with the shity paper masks I can't smell anything!! But after cutting concrete I look like I've been at Pablo Escobars for the weekend!!!

[OldMarine]

Got me a large pack of tongue depressors for wings and am working on boring a PVC jig for drilling nozzles on Tourbillion tubes. I've not found much info on them other than Danny Creagan's site and some passing references in FAST and Hardt's Pyrotechnics. I've gleaned two methods and intend to try both and compare this weekend.

 

I'm going to start with a 65-25-10 BP and work my way up from there. One design has 2-45° downward angled nozzles and the other has the same with 2 additional nozzles pointing straight down nearer the axis. I'm leaning toward the latter as I can picture 2 different comps, one with more power in the outer and a metal bearing on in the inner increments. I think this would give a mini girondola effect.

Edited September 24, 2016 by OldMarine

[Pyrophury]

There are instructions for making the four nozzle "helicopter" tourbillons on p141 of Turbo Pyro.

 

Personally I prefer the single nozzle version, like the one on PassFire. This was made with 60:30:10 +10%Ti (fuel was a bit too coarse):

Edited September 24, 2016 by Pyrophury

[OldMarine]

Doggonit! Turbo Pyro is another source I keep forgetting. Thanks!

[mikeee]

OldMarine,

 

The old Westech manual has a section on Tourbillion and Buzz Bombs.

[OldMarine]

Thanks Mikeee, I have a loaner copy I plan to study on ASAP.

[Pyrophury]

Rammed a 3/4" rocket and mounted a 3" round shell on to it...

 

http://pyrobin.com/files/Rocket_4.jpg

 

I'm just using up the remains of the modified green pearl stars and some crackling microstar rejects, to dial in the rocket delay and burst charge/pasting, before I start the building proper.

Edited September 25, 2016 by Pyrophury

[Pyrophury]

Just tested some crackling matrix stars...

 

 

The stars were 10mm x 12mm (cylindrical), crackling microstars were red lead based with the addition of 3% FeTi (60-80 mesh), pushed through a 16 mesh screen, 1:4 microstars to matrix composition which is experimental:

 

Parts:

KNO3, 60

Charcoal, 5

Sulphur, 15

Silicon, 5

Dextrin, 5

 

I want to slow it down a bit but I don't want any visible tail, so was thinking I'd add more sulphur?

[ExplosiveCoek]

Nahh, my bet would be bit more charcoal. Or just decrease the KNO3 percentage.

[Pyrophury]

Nahh, my bet would be bit more charcoal. Or just decrease the KNO3 percentage.

 

I don't want it as fast as BP, nor do I want a visible charcoal tail though... I tried a D Blesers dark relay, but that was too hot and just burned up my microstars before they exploded.

 

 

I let off my rocket this evening: https://youtu.be/XVbk4LbrEok - the delay was better than the last, but perhaps could of done with one more increment.

 

However the break was way too hard, all but a few of the stars got completely pulverised. I used 1/2 tsp of 7:3 flash dusted on MCRH, I thought this is what I had used last time but thinking back perhaps it was only a 1/4 tsp... the only other difference was the one extra layer of gum tape, which only covered about a third of the shell.

 

It's a bit late in the game, but I wonder if it might be worth switching to "slow flash" and try to dial that in instead?

Edited September 29, 2016 by Pyrophury

[Pyrophury]

Another test...

http://pyrobin.com/files/rocket%20test%202a.jpghttp://pyrobin.com/files/rocket%20test%202b.jpg

 

This time with just 1/4tsp of 7:3 flash.

 

 

I was very disappointed with the break, it wasn't that big or at all round/symmetrical... but at least I didn't smash the stars to dust this time.

 

I think I'll go back to 2 layers of paper and 1/2tsp of flash, I'm not sure.

Edited October 4, 2016 by Pyrophury

[Pyrophury]

Made half a dozen 3/4" rocket motors...

 

http://pyrobin.com/files/Rocket%20Motors.jpg

 

they contain 50g of 60:30:10 propellant, total weight is about 100g. Took me around 25 mins to ram each one by hand.

 

Also made another test 3" ball shell header...

 

http://pyrobin.com/files/3inch%20ball%20shell.jpg

 

gone back to 2 wraps of gummed tape (effectively 8 layers of paper) and 1/2tsp of flash booster.

[OldMarine]

With instruction from Lloyd I was able to make some "Quick-Shot Gerbs". I was able to use an existing spindle and screen mixed powder and Boy Howdy are they fast!

[ExplosiveCoek]

Pyrophury, the delay on the rocket was a tad too long also. This gives the rocket a downwards flight already, and therefore a downwards momentum to the stars. Break needs to be really hard to overcome that.