Random Thread #1

[50AE]

It's very friction sensitive, but shouldn't have traces of acid to pose self ignition danger. Correct me if I'm wrong.

 

It's still dangerous to handle though. Small amounts should be handled.

[Mumbles]

Sulfur, especially the acidic ones, sensitize it to impact. Antimony Trisulfide sensitizes it to friction. There are more routes, but those are the main ones.

 

The safest way to make this is to add the chlorate and NC lacquer into a soupy mix, and then add the antimony. These kinds of mixes are pretty standard, because they take fire so easily. There is some speculation that thermalite uses a similar mix with some metal powder in there. Once bound it doesn't live up to the legend of sensitivity. If I were going to be making a batch of these, I'd give them a dip in straight NC lacquer or something similar at the end to give it some protection just in case. They're no more sensitive than commercial e-matches, which maybe isn't as reassuring as it sounds.

[Swede]

Frank, the xmas tree bulb is definitely on my "to do" list, and I believe you're right in that the cost and consistency would be excellent; plus, you get free lead wire built in. With these things, you need to supply your own lead wire.

 

The slurry I used was created by adding antimony trisulfide to a wetted (aqueous) chlorate mash. The mixture stays wetted and in a sealed container, in very small amounts. The matches are dipped once, and dried, then coated with NC.

 

I'm sure there are safer mixes, but I knew this one would ignite easily. I tried to ignite one by friction and had no luck.

[_DB_]

Hmm, while we are at it I'll make a list of dumbasses nearly geting killed.

 

A rocket in the Kitchen, great idea!

 

 

 

What if it cato'ed?

 

 

Feel free ro add on.

 

This was pretty reckless - http://www.youtube.com/watch?v=Hw4yjc9MZhQ...feature=related

[Richtee]

Richtee, would it be possible for you to just get legal? Apply for a type 54 with contigency storage at a commercial fireworks supplier for the transportation/handling issue, and for your own material, build/buy an indoor magazine that meets Type 4 requirements that could be stored in an unattached garage or shed that locks?

Probably, Frank. But due to the current economic outlook..I'm kinda lucky to have storage for my family at this point. I am self employed in the electronics arena, doing home and commercial A/V, security and communications, and not many people are spending on anything that makes money for me...mainly just the security, and that's cut-throat as hell.

 

Soo, if I DO hit the lottery, bud- I'll have a compound! But till then- I keep reading :{) Oh and cooking!

[Ventsi]

Well I'm building me self a "new" Ballmill since the *thing* I have now is just way too ghetto.

 

First thing I did was to pop a printer open , I was thinking I would be able to use the motor but the little whimpy thing just wont cut it.

I found some perfect steel and alumunum rolers ,perfect size,grippy foam coating,one of them fits perfectly in my bearings.!

I also got some E-match lead wires, two potential spindles and some toner powder for arial black salutes .

 

Next I'm tearing up a vacuum for its motor aand bulding a soundproof box.

You guys want pictures ?

[tentacles]

Ventsi: If you're planning on using a vacuum cleaner motor for a ball mill, I'd suggest against it.. They're not rated for any kind of duty cycle without forced cooling, and aside from being noisy, they are universal type motors with brushes, and will make a LOT of sparks.. Oh, and they run at 6000-11000 RPM.

[50AE]

Today I opened my dead scale again with optimism, thinking that I may get it work. And I found the problem ! It was a bad connection connection from the tiny wires to the censors.

But sadly, I can't fix it... for now. There were 4 colored wires (white, black, red and green) soldered to 6 non colored, laquer coated wires, leading to the sensors themselves. And I don't know the correct connections. I couldn't know them, because the Chinese have covered the solders in a sort of a gum. I had to remove it and cut all the connections.

My options are to experiment and to learn more about these scales from somewhere.

 

Edit : I found out that the scale works by a strain gauge system. There are two strain gauges, and 3 wires come from each one of them.

Edited June 8, 2009 by 50AE

[Miech]

If there is a type number on the sensor you can probably look up the data sheet. Then you could figure out which wire from the sensor should be connected where. I would guess the red and black are for supplying power, and the green and white for data. At least that's whats usual for USB cables.

[50AE]

I guessed the same. Red and black are definitely the power supply, I already found out.

 

I tried many methods to wire and still didn't work. The three results that I get are:

-The old error

-0 grams and nothing, while I press on the sensor

-Crazy variations of the values, without pressing on the sensor.

 

Sadly, there's no number on it.

 

Here's a photo :

http://img269.imageshack.us/img269/9427/clipboard01uls.th.jpg

Edited June 9, 2009 by 50AE

[Swede]

50AE, that's a shame. What was the capacity of the scale? It is possible to destroy a load cell with excess force, and the more sensitive the scale, the easier it is to be permanently damaged by bumping, jarring, or excess mass. I've got a milligram scale that I treat like a fragile jewel. They can be overly sensitive to vibration and handling damage.

 

I'll just toss this out, I think you know it already. Most unamplified load cells have a three-wire arrangement, power, ground, and signal. Inside the load cell is a type of wheatstone bridge, with the resistance varying by deformation. If you apply the correct voltage, then measure the voltage on the signal wire under load, you'd probably see 0 to 100 mV or so. The 0 to 100 mV are typically fed to an instrument amplifier, and the firmware in the scale translates the signal to a displayed mass. It's not linear, but it's close. Good scales have ways of dealing with the non-linearity.

 

As to why there are two load cells, you got me there. Maybe the system looks at the average of the two? I dunno.

 

Edit: just saw your comment -

Crazy variations of the values, without pressing on the sensor.

This is typically seen when the scale is in "calibration" mode. From your description, it sounds like the scale might be in that mode. Have you tried the full recalibration procedure? Usually it involves pressing and holding a button on power-up, or similar. Edited June 9, 2009 by Swede

[50AE]

The scale's a cheapo, bought from eBay. It measures to 1kg, with 0.1g precision.

 

So how it happened... One day I gave it to my sister. Tomorrow, she returned it to me, saying that it doesn't work. When I was turning it on, it showed me "Err2".

I opened it and found nothing unusual. I closed it again.

 

These days, I decided to open it again, with optimism. I was checking the wires, to see if everything's ok. Suddenly, I touched the gum with all the connection and the scale started to measure again ! I was sooo happy.

But I didn't want to leave it this way, so I cut everything, to redo the connections properly. . I couldn't find out the correct wire positions, because of the damn white gum, covering everything.

 

I will now try to solder and assemble it with the "crazy variation" wiring and try to calibrate it, maybe it will work.

Edited June 9, 2009 by 50AE

[scottlpool2003]

Loving the new look guys!

[50AE]

I'll share my yesterday's story.

 

I found a mixture of KClO4, Plaster of Paris and Shellac in the passfire formulas. It was in the colored fires section and it was said that it's pink. Because I've already moved most of my chemicals from here, I didn't have KClO4 but KClO3. I wanted to try with it. I mixed a small batch and it gave a very beautiful orange color.

I was very happy about it and I thought to use this mixture in the future. But moments later, I "slapped" myself in my mind, remembering that plaster of Paris is CaSO4 and that a chlorate + a sulfate are no-no.

 

Anyway, I shared the video of the burning mixture with other pyro members. I said sadly that it's unacceptable because of the sulfate and chlorate. One of them started to argue with questions like "Why ?" "Why do you have to throw it away ?" Why are you always a sheep guided by books ?" "Why do you believe their crap ?".

He was insisting that "some of the book crap is unjustified". He agreed that a chlorate + sulfur mixture is very sensitive, buy why should be one with a sulfate.

 

So he really angered me, and I was still defending the pyro books, because the people who have written them have much more knowledge that all the pyro members in the chat room ! Telling that Shimizu testings are injustified, for me was like telling that Isaac Newton's force law is fake and we should find another.

 

It was a very long discussion with many other points, though I'm lazy to write them. Finally, he was so insisting that I decided to "waste my time" for him, testing friction and shock sensitivity of the composition. He insisted that the mixture wouldn't self ignite, because the plaster contains also calcium carbonate which neutralizes the acid and so on...

 

I decided to take out my mortar and pestle, ideal for friction testing. Friction is more important for me than shock.

First I put on my safety gear, glasses and gloves. I really didn't need the dust mask.

I put one gram of the color composition and started to grind it. Well, it was a pain even to get a crack. I had to push half of my body weight down and make very brutal movements to hear a small crack.

I reported the results to the guy, telling him that the result was "normal-moderate" friction sensitivity for a chlorate composition.

But I wanted also to compare it to another chlorate mixture ! I remembered that I've never tried chlorate and sulfur.

 

Good thing that I kept my safety gear. I put some milligrams of sulfur with some of KClO3. I started gently to mix these in the mortar. Next, I pushed down a little and I heard a moderate crack. I said that it's not enough, so I pushed more. 1 turn, 2 turn, 3 tur... BAAAANG. Scared the hell out of me ! It did, because I didn't expect it to be so sensitive, knowing that the previous mixture of chlorate and sulfate wasn't easy to set off. My ears rang for a minute or two.

 

The final thoughts are :

 

Sulfur + chlorate is very sensitive, as they say it !

Sulfur + sulfide... I haven't tested, but some say to be very sensitive with Sb2S3

Sulfur + sulfate : Disputable.

 

I have kept a part of the composition for storage in a safe place in case it self ignites. I'll test it again for friction in a week or two.

I will maybe also do a friction test of CaSO4:KClO3 alone.

Edited June 13, 2009 by 50AE

[WarezWally]

There seems to be a bit of an overreaction from people when dealing with ClO3- and sulphur, its a bit like the anti drug people who give speeches in schools detailing how you will instantly die if you take drug x, y or z.

 

It all comes down to how much of a risk you are willing to take, much the same as everything else in life. Fairly sure I still have a small batch of KClO3, indian black and sulphur sitting around for curiosity's sake, sure if you hit it with a hammer it will react accordingly but I haven't been woken up by it spontaneously going off and its been over a year now.

[50AE]

I also did some other friction tests today, I will classify them from the least to the most sensitives :

 

-KClO3 + CaSO4

-KClO3 + Sugar

-KClO3 + CaSO4 + Dextrin

-KClO3 + Dextrin

 

Dextrin seems to sensitize the chlorate very much.

KClO3 and CaSO4 alone doesn't crack, or very little when I press much, maybe because the sulfate is also an oxidizer.

Edited June 13, 2009 by 50AE

[Swede]

Interesting tests, 50AE. Remember, chemically, sulfur, sulfates, sulfites, etc are different beasts, with differing chemical properties. When a sulfate dissociates due to moisture, you have an SO4 ion swimming about, very different from elemental sulfur. Chlorate tends to be more sensitive with almost all fuels, and as you've seen, the sulfur is bad. Contact of chlorate with BP is much the same as sulfur, since the BP has elemental sulfur in it.

 

I know you know this - the sulfur in BP primarily lowers the ignition temp... makes it easier to ignite. One can always use sulfurless BP with chlorates if need be.

 

Chlorate is not the devil; most of the accidents stem from guys who just didn't know.

 

I've always liked the idea of taking a comp you are not familiar with, and making a very small batch, a gram or two. You can take the gram and subject it to all sorts of torture with little danger as the mass is so low. Hammer, friction, mortar and pestle, etc. Even perchlorate comps considered safe will BANG with a modest hammer blow. That doesn't disqualify them, it's just the nature of the game. KP will certainly POP where BP doesn't. Whistle, same. Perchlorate IS safer than chlorate, but it is still more sensitive than nitrate comps.

 

Thank you for the interesting tests.

[50AE]

Thank you. I may do more tests in the future.

[tim]

Just making a post for this guy.

 

-Mumbles

[Mumbles]

Calcium sulfate is potentially dangerous on more than one level. The general avoidance of sulfate is that they tend to be naturally acidic. Sodium, Potassium, and Calcium arn't, but Barium might be. The carbonate in the plaster may help, along with it's low solubility. One other issue is the formation of calcium chlorate, which is rather explosive.

 

The one thing lacking with your tests is that they are not done in a finished form. Try hammering/grinding on the stars made. There may be a difference. Just like star formulas burn differently once bound, the friction/sensitivity properties change too.

 

I also believe that the chlorate legend is over exagerated. One thing that people always ignore is that contact is far different from mixing. A BP fuse into H3, or a BP burst with chlorate stars is not going to cause them to spontaneously self destruct. Sulfur primarily sensitizes chlorate to shock(but friction too as you've seen), so they may go off if a shell doesn't light and strikes the ground. It's not going to go off from the lift charge, nor will your stars blow up upon bursting.

 

If you look at the table of values in "Principles of Pyrotechnics" by Shidlovskii in chapter 9, you'll see that the coresponding perchlorate equivalents are nearly just as sensitive to shock as the chlorate for sulfur and a few others. Some day I'd like to build a tester. Perhaps as a Passfire article.

[50AE]

I will test as soon I have the possibility to. I just don't have a hammer and concrete here to test for shock.

 

Is the Shlidlovskii book translated in English, or it's still in Russian ?

Edited June 16, 2009 by 50AE

[Mumbles]

English. I wouldn't even know where to find it in Russian. Many of the references are in in Russian journals and books, so they're hard to check, but it's fairly well written, and nothing seems too unreasonable. It's kinda pricey otherwise, but I ended up getting a good deal on ebay.

[TheSidewinder]

Just making a post for this guy.

 

-Mumbles

 

I hope this solves whatever posting problem he had, because everything I checked in the ACP with his account was normal.

 

Are you here, Tim? Can you post now?

[Swede]

On hammering comps to test - Nothing new except for me, but I found that concrete is a poor surface to hammer a comp into compared to a small block or plate of steel. Sparking, perhaps? I don't know, but I do know that the same sensitive comp placed on a steel plate will pop with much less of a hammer swing than the same one on concrete.

 

I've always wanted to set up a drop-rig. It wouldn't be hard. Hang a kilo of steel by a small but decent pulley and some fishing line, then measure the drop with a ruled background like the Mythbusters use in so many of their shows. The "target" could be made very fancy; a small steel piston nested in a plate. The comp is placed under the piston, and the dropped steel strikes the piston rather than the comp itself. I think it'd be more consistent that way.

 

An H-frame hydraulic press could probably be converted into a dandy drop-rig.

Edited June 16, 2009 by Swede

[50AE]

That would be ideal, because you can easily calculate the exerced force of the hammer on the comp.