Flash Without A Scale

[endotherm]

I have dreamed of attempting to make 70/30 perchlorate/aluminum flash going on 5 times now!, all unsuccessful. Both products are very high grade pyro grade materials. The flash was succesfull with 1 out of the 5 batches I made, so it is not the chemicals. My problem is measuring out the materials for the flash, does anyone know any good way to do it since we know the density's, like 2 teaspoons perchlorate = _ teaspoon aluminum? I think this would be helpful to many memebers of the forum because not everyone has microgram accurate scales.

[Anthony]

It takes a bit longer, but you can mix comps to "taste". Start with an amount of one component (say KClO4) and add some Al to it, mix, scoop a little of the mixture out with a small spatula or similar and burn test it. Keep adding Al in small incretments until you have a mix that burns fast and completely.

Goes against safety warnings a bit, but you could just make larger batches of flash to overcome the innacuracy of cheap scales, such as kitchen/diet scales.

[endotherm]

I figured out my problem. I was thinking that alumium is much denser than perchlorate so i was using very small amounts of aluminum in the mix. It turns out that they have similiar density's with aluminum being 2.70 and perchlorate being something like 2.48. I was in for quite a shock when i out of frustration attempted to light a teaspoon of my next "unsucceful batch" of flash with a incense! Will not be doing that again, or possibley hearing or seeing again for a few hours. But hey, it's all about the love of the game!

[krimmie]

I have a good scale, so I put the "teaspoon" method to a test. I used Chinese fine KCLO4 from Skylighter(don't know the exact sieve size) and 8 micron flaked blackhead purchased from the same. I measured them three separate times...these figures are the average(they only fluctuated by .2/gram anyway). The measurement was a "level" teaspoon.

1 Teaspoon of KCLO4 = 7.5 grams
1 Teaspoon of Al = 3.7 grams

When combined you have a total of 11.2 grams, which amounts to 67% KCLO4 and 33% Al. I had a dream that this worked just fine for a volumn measurement!

Hope this helps

"The Bottle Washer" (oops, I turned into Amateur)

<small>[ June 16, 2002, 01:34 PM: Message edited by: krimmie ]</small>

[endotherm]

Why is the perchlorate so much heavier than the aluminum? The aluminum is denser, and finer!

<small>[ June 16, 2002, 05:27 PM: Message edited by: endotherm ]</small>

[Arkangel]

Al is a light metal anyway, but it's probably because of the structure of the Al. If it was spherical, or larger particle sizes, it would be a denser powder. As it is, it's just so light and fluffy and not a compact powder.

[kingspaz]

i think what arkangel is trying to say is that the AL powder is incredibly fine and has many air spaces between it. if you compressed a sample of perchlorate and Al powder under the same pressure then the Al should have an apperently higher density as more air will have been forced out of it. that make sense?

[Anthony Privratsky]

I have 1 pound of German Black Flake Aluminum powder (600 mesh). I also have a pound of Potassium Perchlorate. Im makin a really powerful flash powder but i cant find a good scale ne where around.
1 part- PP
1 part- Al
Would that really work?

[inferno]

The Al powder will have many air spaces between it, and also as its a fine powder, the "density" is more on how compacted the powder is than the density of the Al atoms when comparing with teaspoons.

And as for buying fine KClO&lt;sub&gt;3&lt;/sub&gt;, why bother? You can buy it in regular crystals and make it finer yourself, it costs a LOT less!

[googol]

How much precision is considered 'good'? What capacity should I look for?

krimmie uses .1 gram precision in the measurements given.
I've looked at a .01 gram scale ( http://balance.balances.com/scales/1 )
with a capacity of 200 g. Does this seem like enough capacity or would people suggest more capacity and less precision?

I'd probably get this http://balance.balances.com/scales/853
if 200 g is adequate capacity and .1 gram is adequate precision.

comments?

[The_Duke]

If you are using it for flash powder then you shouldn’t need anything larger. Besides, you should never make that much flash in one go anyways.

If you are making 10g batches of flash, 0.1 % accuracy is fine.

PS. Ebay is a great place to find cheap scales.

[googol]

the_Duke, thanks for the reply.

but, I meant my question in the general sense, not specifically just for flash.
I was looking for what guidlines someone might suggest in the way of capacity and precision.

when you said
> If you are making 10g batches of flash, 0.1 % accuracy is fine <

did you mean .1g/10g ? because this is .01 eg 1%, not .1%
or did you mean measurements accurate to .1g are fine when total mass is
10g?

[The_Duke]

did you mean measurements accurate to .1g are fine when total mass is
10g?

Yes I did, sorry about the confusion.

A small scale accurate to 0.1g like the one in the picture will do very well for most jobs, but if it is exact precision measurements which you are after I would suggest looking around medical suppliers for a scale that is accurate to 1mg (that is 0.001g), or you may want to look at gun shops or online somewhere. I have seen many nice scales for measuring grains (1 grain is 0.06480g) or milligrams of Gun Powder or Smokeless Powder for use in firearms. These types of scales can be expensive but they are very accurate.

[Jacks Complete]

I'd second that. Go to a gun shop that sells reloading gear, or look on ebay or whatever, and find a powder scale from RCBS or Lee (or anyone!) for not that much money, and it will measure happily forever with weight differences as fine as 0.1 grains, which is 1/7000th of a pound!

Make a spreadsheet with the number of grains, pounds and grams on it, and blutak it to the scale for easy reference.

They all go up to at least 500 grains, and some go to 2000 grains.

Because they aren't electronic, you can trust them, and so use them to weigh things accurately for use as test masses for other (non-energetic) experiments, as well as for testing other scales.

[nbk2000]

I've used kitchen scales for making flash powder, but then I was also making enough for dozens of 'sticks', not little cherry-bombs, so...

The larger the quantity you'll be making at one time, the less important the accuracy of your scale.

If you only a scale for making a few grams at a time, buy a postal scale at an office supply store, the kind that you clip the letter onto and dangle by the hand. This is accurate enough, and cheap enough, for your use. Use an envelope as the scale pan. :)

[Jacks Complete]

Postage scales are a good idea.

I should just point out that the thing with scales for things like this is repeatability, more than accuracy. As long as the scales will always weigh the same mass and give the same reading, and they are fairly linear, you shouldn't go far wrong, e.g. if the scales say 1Kg but it is really 900g, you are fine, as long as it is always a reading of 1Kg for 900g, and you get a reading of 500g for a mass of 450g.

What would be very bad would be a scale where 1Kg = 900g and 500g = 550g.

Also, beware the electronic scales - a lot of them have very questionable accuracy, repeatability and drift, despite the appearance of electronic precision! Also, they can be thrown by electrostatic charges on things like powder (or so I have heard)

[nbk2000]

That's why I like mechanical triple beams, as you can easily see any drifting, which is something that the 'black box' electronic scales don't allow.

[xyz]

Jack, electronic scales are fine so long as you make sure you have a proper set of calibration weights and calibrate them every so often.

I have an electronic scale ($80AUD - Ebay) that goes 0-200g in 0.01g increments, and over the course of a few months it might lose maybe 0.02g of precision and need recalibrating, but it's still plenty accurate even if you don't recalibrate it every few months (remember 0.02g = 2 hundredths of a gram). It converts automatically between grams, grains, ounces and carats at the push of a button - no conversion tables needed.

I mostly just prefer electronic scales due to their speed, but yeah, if you want total reliability and simplicity then go with a balance.

The scales that go down to an accuracy of 0.2 milligrams look nice, but oh the $$$$$$