What did you do today in pyro?

[BlueComet24]

Today I "lathed" (using a hand drill and a sketchy jury rigged setup) a 5/8" (15.9mm) dowel down to 9/16" (14.3mm), which seems to be a practically nonexistent size in hardware stores and such. Now I can ram 9/16" helicopters! I made three of those and two 1x2.5" sorbitol rocket candy darts.

[mikeee]

Today I cut out end disks; 150 each of 2" and 3". All by hand with scissors! I just have to make some punches.

MadMat,

 

You need an Allpax cutter or Spearhead cutter.

These are some of the best tools to use for cutting end discs.

[memo]

i just bought a allpax off ebay. paid $55 including frieght . it was old but in great shape. even had the booklet with it. there is one right now on ebay, she is asking $75 she has had it up for sale for a while. make her an offer.

 

memo

[Pyrophury]

Rammed a 1lb core burner to lift a 3" ball shell I constructed last weekend...

 

http://pyrobin.com/files/rocket_3.jpg

 

With 3/8" green pearl stars (Spanish pdf) I rolled the weekend prior to that...

 

http://pyrobin.com/files/Green%20Pearl%20Star%20thumb.jpg

 

Let it off this evening...

 

 

I was happy with the results but unfortunately neither camera picked up the green, it was definitely green in person although a bit washed out. You can see the green a bit better in this star gun test: https://youtu.be/uZ4-T4bn4QE, but the tail wasn't that great either.

[OldMarine]

Made colored zips for the first time. Added 30% red gerb comp to BP and WHOOOEEE! They were bright and buzzy!

[BlueComet24]

Patrick, what size did you make them, and what was the gerb comp you used? They're really fun made with rocket candy in 1x2.5" size. You should try making helicopters, too. They're really similar in construction to zips/darts and are quite impressive when compared to consumer "bees" when made with 1/4" ID and hot BP fuel. Just make sure to aim the nozzle down at 45° and bend the wings the right way.

[OldMarine]

I made them with 2¼"pieces of 5/8"id tubes. The Gerb comp was from Ned's article in Skylighter:

Red Gerb Composition Ratio 16-Ounce Batch

Strontium nitrate 0.44 7.05 ounces

Parlon 0.17 2.70 ounces

Magnalium, 200 mesh 0.17 2.70 ounces

Titanium 0.13 2.10 ounces

Red gum 0.09 1.45 ounces

Total 1.00 16 ounces

[Pyrophury]

Made another micro batch of rolled stars today, started with ~350 #9 lead shot cores(20g) and 100g of composition (Red 1 - Spanish pdf).

 

http://pyrobin.com/files/rolled%20stars.jpg

(click to see video)

 

Ended up with about 200 5/16" and 150 3/16" stars(primed). I'll use the smaller stars as cores for a bright streamer.

 

I was left with about 15g of composition, which I made into some 3/8" cylindrical stars with my homemade star plate.

 

http://pyrobin.com/files/Star%20plate_1.jpg

[mikeee]

Worked on some drying screens, made several designs, this one is made of laminated birch plywood.

 

[Pyrophury]

Still had about 80g of the green pearl composition left over, so I modified it so it would be similar to PiroArt86's green wave, by increasing the amount of magnesium and chlorine donor. But instead of PVC I used parlon and as my composition already contained red gum, I couldn't substitute that with charcoal/sulphur. I also don't have access to 100/150 mesh atomised aluminium and it already contained 15 parts 70 mesh aluminium (not sure what kind, but it's not flake), but I do have bright flake (Eckart) so I added 5 parts. As a result it turned the composition a silver colour (as well as fluffy and very messy to work with), they looked like ball bearings when I'd finished so it was only fitting that I primed them with pinball prime - about 150 stars, total size 3/8".

 

http://pyrobin.com/files/Green%20Pearl.gif

 

I also primed about 250 Shimizu white AP twinkler cut stars (also with pinball prime), which were made by binding with NC lacquer, rolling into a sheet, dusting with prime before being cut into cubes (3/16"). These ended up being bigger than intended, just over 1/4" (primed). I should have cut them smaller, each cube will strobe 5-6 times at about 1.5Hz, so they may end up strobing all the way to the ground .

 

http://pyrobin.com/files/White%20Twinkler.gif

Edited May 2, 2016 by Pyrophury

[Pyrophury]

Tested the modified green wave in the star gun last night, although the green was brighter and the stars burned a lot faster, the silver tail was even less apparent and more of a gold/charcoal colour. Perhaps PVC is superior to parlon in this particular application?

 

http://pyrobin.com/files/Green%20Wave.jpg

 

Rolled and primed more stars this weekend, Green 2 (Spanish pdf), about 200 - 8mm and 100 - 6mm...

 

http://pyrobin.com/files/Spanish%20Green.jpg

 

And about 120 Lancaster Silver (p222 of FPAP), containing -100# magnalium and -100# and -250# atomised aluminium (not too dissimilar to Spanish White Pearl). The atomised aluminium isn't as messy as the flake aluminum, but they were still difficult to roll (just wanted to slide against the sides of the roller).

 

http://pyrobin.com/files/Silver%20Wave.jpg

 

These are undersized (7mm) and still need priming, probably with a Pinball type prime. I also ball milled some Bleser Blonde Steamer #1 (without the metals) for an hour, not the 12 hours he specifies, but I'm sure that's plenty for my mill.

[lloyd]

Darn, Man! What the heck can you DO with only 120 stars? Even if the first shell worked, you couldn't reproduce it! (And twice is the minimum 'success rate' to ensure you got it right!)

 

Lloyd

[Pyrophury]

I've always done things on a comparatively small scale(by necessity), and now that I have a finite supply of perchlorate, I've had to scale back even more. I know it seems like a lot of work to produce one shell/rocket header, which may not even work, but I still enjoy pyro even in this modest way.

[Seymour]

You have to work within your means

 

I have to say I'm quite impressed by how well you have rolled those stars given how small the batch is. I have indeed rolled star batches only a few hundred grams, but it is just as fast and much easier to roll 10kg.

 

Especially much easier to have uniform sized, very round stars. Ignoring the batch size for a moment, those stars are very uniform and free from blemishes. Considering the batch size again, this is especially impressive

[BlueComet24]

Tested 60/40 KNO3/fructose. I'm pleased with the results. Fructose truly melts (at 103°C) just like a sugar alcohol, but is cheaper than xylitol, sorbitol, etc. but more expensive than sucrose. It's hygroscopic and brittle once cooled like ordinary rocket candy and more energetic than a sugar alcohol. I'm not certain how it compares to sucrose as far as power, but it seems pretty similar.

[stix]

Tested 60/40 KNO3/fructose. I'm pleased with the results. Fructose truly melts (at 103°C) just like a sugar alcohol, but is cheaper than xylitol, sorbitol, etc. but more expensive than sucrose. It's hygroscopic and brittle once cooled like ordinary rocket candy and more energetic than a sugar alcohol. I'm not certain how it compares to sucrose as far as power, but it seems pretty similar.

 

Sounds interesting. What casting methods are you using?

 

I haven't tried Fructose but was lucky to come across some cheapish Sorbitol (melts at 95°C). My current fuel formula is still yet to be tested in a motor.

[BlueComet24]

I didn't make a rocket motor (so far all my intentional motors (long story) have been BP, but I may try rocket candy soon) but I did pour it into a 25mm and 17mm tube, which it had no problem filling without air pockets, as I was tapping them while pouring the RC.

My process was to grind the KNO3 finely and add it and the fructose separately to an electric skillet preheated to about 107°C. The fructose melted readily, but I don't think it was quite as readily as xylitol or sorbitol, which could perhaps be attributed to the fact that I had it only about 4° higher than the melting point, whereas I usually go about 10° over for xylitol or sorbitol. I stirred the chemicals together, and the mixture had a yellowish color like sea foam candy and was about as viscous as the same ratio of KNO3 and xylitol or sorbitol.

It remained flexible while warm like a sugar alcohol. After cooling it got sticky (seems to be hygroscopic) and brittle (it passed the snap test).

It burned about as vigorously as sucrose RC, but I'd have to do a side-by-side test to really tell which is better. All-in-all, I'm pretty happy with fructose.

Edited May 10, 2016 by BlueComet24

[stix]

I've always had issues with pouring r-candy into small tubes - it seems to "set-up" (go hard) too quick. My current method is to make like a "putty" and press into the tube.

 

You may be able to tell that I love "sugar fuel". Mixing in the skillet is very satisfying, and testing the results is very quick.

 

Cheers.

[dagabu]

With small tubes, you may want to consider grating the R-candy while its still somewhat flexible and press/ran it like a BP rocket. You can get air pockets though so use small increments. It does work though.

[BlueComet24]

I was even thinking that remelting the fuel pellets inside the tube might be possible.

[dagabu]

I was even thinking that remelting the fuel pellets inside the tube might be possible.

 

It is but only if its compressed, if it was poured in and has an air bubble (almost impossible to avoid) the bubble will swell causing an even bigger pocket. An oven (outside) or a hot air gun works well.

[otto]

I just opened my UPS package. Made a deal for 60 some pounds of used Zirc M media for just under $5 USD per pound. I am very happy... Might even be a little better than that. The shipping label said 66# but I haven't weighed it yet. This has been languishing on eBay for years. I finally got the vendor to separate the media from the jar/drive it was with.

 

He did say it was in previous use by a capacitor manufacturer and will need to be rinsed. I would have planned on rinsing any used media before use. I'm not sure what if any hazard might be present but I'm going to proceed as if there may be some toxic residue and use suitable PPE. Perhaps one of you might have some insight on that.

 

Anyway, all nice 1/2 inch cylpebs. The only way that box could have weighed more for it's size would be if it was lead. Should be enough to fill all three of the 20# Lortone jars I liberated with their motor-less drive a couple of years ago. I should be able to spin all three jars on that drive (1/2 horse TEFC) and probably churn 3 Kg of BP in one session. Next will be some decent BP with good coal instead of the first few trial batches I made with commercial airfloat. Even at that I was able to fly some 4 oz. endburners with it.

 

Slowly but surely..... This year is going to be fun!

[OldMarine]

Lit some of the BM I made a couple days ago with the new BM machine. Crappy, crappy, crappy.

The only difference from what I've made my hank and knead match with is the addition of 2% CMC. I only had 2% dextrin in the mix so I doubt it's over bound. The only thing I can figure is that I added the CMC after the initial milling and only milled it in for a few minutes before mixing my slurry allowing it to still form small clumps in the mixture.

[dagabu]

Lit some of the BM I made a couple days ago with the new BM machine. Crappy, crappy, crappy.

The only difference from what I've made my hank and knead match with is the addition of 2% CMC. I only had 2% dextrin in the mix so I doubt it's over bound. The only thing I can figure is that I added the CMC after the initial milling and only milled it in for a few minutes before mixing my slurry allowing it to still form small clumps in the mixture.

 

Does it still make any sulfur bubbles of dross when burnt? It could still be wet.

[OldMarine]

Very little slag. I was going to throw it in the burn barrel but I'll let it dry til Saturday and give it another chance. I'm also placing some small pieces (6") in my dehydrator overnight.