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Kno3 slow flash booster


Sparx88

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Ok I have used it before but never did a side by side comparison againts BP. I decided to give it another try as I generaly don't use/need boosters. Well I shot a video of 1 gram each my granulated 2fg bp and kno3 slow flash (5,3,2). The kno3 is the same in each, highly milled, then 5413 3 micron flake aluminum and good sulfur, same kind in each.

 

BP

78 kno3

15 paulownia ccoal

7 sulfur

2 erythritol

1 dextrin

 

Slow Flash

50 kno3

30 5413 alum

20 sulfur

 

How is it that the bp is so much faster? Is it that the slow flash increases in speed and strength under pressure? BP does this too so I'm wondering if using the slow flash is actually going to create a larger break in this situation? The slow flash is the first/right one in video. Is there a better formula for a kno3 based flash/booster?

 

https://www.youtube.com/watch?v=O9OvpuTjf8I&feature=youtu.be

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Why do you put erythritol into your bp?

 

And yes the slow flash really gains speed under compression, bp does so too, but the gain of speed can be described as an exp function. Where a variable is contained, that is specific for a mixture. Bp only has a small coefficient, which means it doesn't gain to much speed under pressure compared to most other non NO3 - C formulas.

Edited by schroedinger
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I haven't tried 5:3:2, but I have tried 2:1:1 using 5413. It burns slower than hot BP in the air but behaves quite differently in a casing. For example, I recently took a very thin-walled paper tube (1.375" ID and slightly under 1/16" thick walls), closed one end with a square of gummed tape, side fused it, dumped in 15g of 2:1:1 left over from making bottom shots, and closed the other end with a square of gummed tape. This casing was basically just strong enough to hold the mix together in a mass, so I wasn't expecting the boom it produced. The tone of the report was lower than if it was in a thick-walled casing, but there was nothing weak about it. Moral of the story is that slow flash is still flash, despite what the name states.

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Never tried your 5/3/2 always made 5/3/2 as K/S/Al. If you burn it in the open it isn't very interesting, but if you put it into just 1 turn of kraft and tie both ends shut, 0.5 g give a nice report.
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No your right, I got it mixed up when I typed.

5 kno3

3 sulfur

2 alum

 

I'm going to try a couple things and see whats up. I figure if it will do well in a flash pot all is well. I just did'nt want to waste any materials on it if it was'nt going to do the job. thank you Wiley I'll try the 2.1.1. The reason for me wanting this is for booster not bangers and I wanted one that does the job but a bit more stable than hot flash. I have, over the years, had my fill of hot flash naughty things and I just don't get excited about it anymore with other more safe and legal ways of making noise. I'm going to try a few things and check in with my findings, thank you for the heads up.

 

The erythritol seems to act as a binder and fuel though I still use a small amount of dextrin. It started out as an experiment to find ways of using it. The first batch I used it in was an instant speed and pressure increase. Just kept tweaking it to what it is now.

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If you're using 5413 and good quality nitrate and sulfur, that should have no trouble going high order in a flash pot, but you'll probably have to cover the muzzle with a square of aluminum tape or something similar.

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Ok, got around to some tests and the results are maybe a bit odd. I just made a small 10 gram batch of the 5/3/2 but reverse like my first post;

 

5 kno3 5 kno3

3 alum instead of 3 sulf

2 sulf 2 alum

 

and things got slower. I mean it burned like green mix. Nice and bright but slooow. By tomorrow night I should have the results with some others. Seems a higher percentage of alum is the way so far. With 2/1/1 next on the test list I'm thinking it's going to be pretty good since the alum and sulfur are equal. I'm not sure yet but it may turn out that it's the sulfur that needs reducing maybe. I want to iron this out before I start prepping for the fourth.

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I don't think you will really gain much from open air tests, how it functions in a shell is a completely different situation. Also, slow flash is often coated on a carrier or mixed in with the burst, so that too would cause it to burn differently than just in a pile.

 

WB

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Sparx for what it's worth, my slow flash is made with 10890 (not quite as reactive as 5413) and when I light it in a small pile, it goes up basically as fast as perc flash. There is not much difference in speed that I can see with my eye, however the slow flash seems easier to ignite. I use my slow flash to dust onto my burst. For example.. I make burst in 1kg batches.. so I figure 3% of total burst weight (in this case it would be 30g), and thoroughly mix 30g of slow flash into all of my burst. So all of my burst has a 3% slow flash boost right off the bat. Then, I add however many grams of perc flash to dial different colors/comps in depending on the break power I want. Hopefully that makes sense. The formula I use for slow flash is KNO3 - 50, 10890 AL - 25, Sulfur - 25.

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I think my kno3 had moisture in it, I put some in the oven at 150 for a few hours stirring it around a few times. And when I was putting it back into the container it felt a lot better and dry. It dawned on me that since all the stars and bp made with it were fine, thats because they were all force dried before use. An Aha moment. :)

It's wet and muddy and rainy so I guess it'll be a day or 2 before trying it out again. Then I'll try all 3 variants again.

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In my opinion flash isn't that much about the Speed but about the Strength.
If you make a shell two hard bp sometimes has difficulty breaking it, but flash can easily break steel mortars etc.

Sparx for what it's worth, my slow flash is made with 10890 (not quite as reactive as 5413) and when I light it in a small pile, it goes up basically as fast as perc flash. There is not much difference in speed that I can see with my eye, however the slow flash seems easier to ignite. I use my slow flash to dust onto my burst. For example.. I make burst in 1kg batches.. so I figure 3% of total burst weight (in this case it would be 30g), and thoroughly mix 30g of slow flash into all of my burst. So all of my burst has a 3% slow flash boost right off the bat. Then, I add however many grams of perc flash to dial different colors/comps in depending on the break power I want. Hopefully that makes sense. The formula I use for slow flash is KNO3 - 50, 10890 AL - 25, Sulfur - 25.

What does 10890 AL mean?

Edited by Stef727
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It is a type of aluminum, similar to 809 American dark. Potent but not as strong as 5413 German dark.
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If you make a shell two hard bp sometimes has difficulty breaking it, but flash can easily break steel mortars etc.

 

If your BP doesn't have enough push to break any viable shell, then there is something wrong with your BP. People boost small shells, not due to the BP not being able to break the shell, but to achieve a specific visual result.

On the topic of steel mortars... The reason we don't use em, is that BP easily can tear them apart and send shrapnel flying. And you don't want to be one of the catchers at that point. Or the owner / user of the equipment.

Steel mortars are still used for special shells, generally of such size and shape that nothing else can lift them, and then you burry the better part of the mortar in the ground.

 

 

What does 10890 AL mean?

 

 

It's an identification number. You call the manufacturer and tell them you want a barrel of 10890, and you always get the same thing. I'm not sure who's identification number it is tho. It's commonly refereed to as "Eckart German Dark 10890", which doesn't make any sense, since the Eckart product closest to a match is "Pyro 5413 H Super".

 

B!

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10890 is a real Eckart product, just not listed under pyro. http://www.eckart.net/fileadmin/eckart/support/brochures/functional_applications/technaluflakes_e_ta.pdf

 

It's approximately -325mesh, and a "dark" or "grey" product, as opposed to a "black" aluminum. It's my preferred aluminum for slow flash, and makes some nice streamers and stars.

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Explains why i've never been able to find it in their product lists. I've just been scrolling to the bottom, and checking the pyro stuff.

On a completely different note. Your link doesn't work. Your tacking on junk at the end again: %C2%A0

Posting links on the phone still does that for you, or is it something else now?

 

Anyway, thanks.

B!

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Surprisingly, this error was from a real computer. Apparently it loves adding a single space at the end of all my links (the %C2%A0 part). I fixed it. One of the last times I made this mistake, several people got accidentally banned. :)

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Since it is so pressure dependant I think I would fill a small tube and make some 'test inserts' and see how those behave.

 

Or just use 70/30 flash so you can easily adjust the amount in a shell. Plus the less you can use, the less the aluminum content and the quicker the burn, and likely less bright light contributed by the flash. You can always make 'safe flash' if making flash is your holdup. I probably have some extra TPA if interested.

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One of the last times I made this mistake, several people got accidentally banned. :)

I know. I still have the PM's with you and Sidewinder. Difference between now and then is mainly you linked away from the forum, not to a none existent page on the forum. Lets not try that one right now. It might still trigger banns ;- )

 

B!

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You may have considered this already, but some builders use whistle mix to boost their shells with great success. It tends to be less violent than flash and more importantly, lacks the retina-burning light burst.

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Yep, that's another one on my list, sodium salicylate. I'll need to get more perc first though. I have a nice bottle jack I want to use in making a press to do whistle petes and rockets. Also for making small whistle inserts. I don't have a problem dealing with 70/30 perc flash really, it's just that it's so sensitive it kinda scares me anymore. I always get that weird gut feeling when making it, that it would be that time it does me damage.

 

I guess I'll have to put 3 inserts into the plan for each of those comps. But even filming it and putting it up on youtube can get me in hot water. I'll have to get creative and put a video together to minimize that risk. Probably have it done by friday night.

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It sounds like you're just psyching yourself out. These slow flash formulas you're testing are actually quite a bit more sensitive to impact and friction than 70/30 is.

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I am with Mumbles on this one. I mentioned this in a recent post about slow flash booster. People hear 'slow flash' and think it's somehow safer. In my experience, slow flash is in no way 'slow', and it's quite a bit easier to ignite. 70/30 is not quite as sensitive as most think.

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I did some more testing in the confinement debt and here's what happened. The 2/1/1 did great, the 5/3/2 (alum-3 sulfur-2) did slightly better and the 5/3/2 (3-sulfur 2-alum) was poop. So it seems that 25-30% 5413 alum does the trick. They were 1/2" id x 1.5" long and 1/8" wall commercial spiral wound resin impregnated tubes. I shot them up about 80' with a hand rolled 5/8" id x 12" long and 1/4" wall with 60 lb kraft guns. I was actually pleasantly surprised. I took all 3 comps and mixed them together and tried another one and that was a good thing it turned out. Combined they equalled 5,2.5, 2.5 or 2/1/1.

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