Replacing hexachlorobenzene in strobes?

[AdmiralDonSnider]

I just reviewed a few nice strobe formulas without AP, e.g. Blesers green strobe or Hardt No.2 and wondered if one could simply replace HCB with Saran or Parlon, both showing a slightly lower chlorine content?

 

Or does the HCB fullfill yet another function than just giving chlorine to the flame, resulting in the necessity to use this particular salt?

 

Apart from strobe stars, can you replace it with Parlon or Saran?

[KruseMissile]

It can be replace 1:1 with dechlorane.

[Mumbles]

I would try parlon, it has been show to exhibit some of the same strobe-y properties as HCB. Besides just being a chlorine donor, I believe it also has some effect on the whole strobe effect. If you look in Hardt at the other strobe stars, they are usually using a 2:1 ratio of PVC:Parlon adding to about 9ish parts when not using HCB. That may be an option.

[AdmiralDonSnider]

Unfortunately dechlorane is as hard to obtain as HCB, coming from the same prohibited insecticide-era.

 

Excellent response, Mumbles. I must have overlooked Meinharts formulations. That sounds like a promising starting point for replacements.

[Mumbles]

I wasn't sure about Meinharts at first because they're all AP based, but it is a reasonable place to start.

 

I did some digging and found a few red strobes based on SrNO3, which should be similar from a functioning standpoint as Hardt #2 and Blesser's. They both use about 6 parts Chlorowax if that is available to you. One other uses around 5 parts parlon, so it must at least allow the effect. Chlorowax is pretty easily available over here (and cheaper than parlon), so it might just be that it is better suited.

[AdmiralDonSnider]

I wasn't sure about Meinharts at first because they're all AP based, but it is a reasonable place to start.

 

I did some digging and found a few red strobes based on SrNO3, which should be similar from a functioning standpoint as Hardt #2 and Blesser's. They both use about 6 parts Chlorowax if that is available to you. One other uses around 5 parts parlon, so it must at least allow the effect. Chlorowax is pretty easily available over here (and cheaper than parlon), so it might just be that it is better suited.

 

 

I just wanted to report that we had superb results replacing HCB with 5% PVC and 2,9% Parlon in Hardt No.2. The result is a nice (cheap) green strobe with a need neither for AP nor for HCB. Nice find indeed.

 

I´d be really interested in those Sr(NO3)2-based strobes. Could you share them, Mumbles?

 

Thanks, and nice strobing everyone!

[swervedriver]

Sounds good Admiral, I have a bunch of good saran and I'm going to give it a try with that. The fuel value of saran is lower than pvc though.

 

Here's a Sr(NO3)2 based red strobe formula I have, never tried it and don't remember where I found it, lol. No sulfur/sulfates are in the formula. Looks to good to be true maybe, I don't know what would make it strobe. The formula is so easy though, maybe try a small test batch?

 

Strontium Nitrate 60

Magnalium -100 mesh 20

Parlon 3

Dextrin 3

Copper Oxide, black 1.5

[AdmiralDonSnider]

A quick question:

 

How can you alter the frequency?

 

Edit: it seems that the flashes are not as distinct (the frequency is not as monotonous) as in case of e.g. Bleser white, don´t know if this is because of the replacement. If anyone knows a way how to resolve this issue, I´ll listen carefully...

Edited January 17, 2010 by AdmiralDonSnider

[Sambo]

With AP strobes the mesh size of the MgAl alters the frequency, the finer the MgAl the faster the strobe rate.

 

Edit: forgot to say, make sure all chems are dry. I had trouble with by strobe rockets due to my AP being slightly damp, the sound and frequency varied a fair bit.

Edited January 17, 2010 by Sambo

[Mumbles]

I'll get in contact with the people I got the formulas from and see if they mind me sharing. At least one or two may be proprietary.

 

I am not sure what you tell you about the strobe rate. It is said to not be as consistent with the organic types. Carefully controlling your MgAl, and priming them completely would be a good place to start. Honestly in a shell or mine the stars are going off so randomly, an inconsistent strobe rate will not be noticeable.

[optimus]

Here's a recent topic on nitrate strobes:

 

http://www.apcforum.net/forums/index.php?s...nitrate+strobes

[AdmiralDonSnider]

With AP strobes the mesh size of the MgAl alters the frequency, the finer the MgAl the faster the strobe rate.

 

That was probably it, thanks. We were using 60-100 mesh MgAl. We´ll give 63µ a try next.

 

I'll get in contact with the people I got the formulas from and see if they mind me sharing. At least one or two may be proprietary.

 

I am not sure what you tell you about the strobe rate. It is said to not be as consistent with the organic types. Carefully controlling your MgAl, and priming them completely would be a good place to start. Honestly in a shell or mine the stars are going off so randomly, an inconsistent strobe rate will not be noticeable.

 

I´m looking forward to the formulas if you manage to get ´em.

 

Concerning the strobe rate: I also wondered if the star shape and size does alter it. I figured that the whole surface of a round star has to finish a dark reaction before it makes a strobe - thus: larger star - longer reaction - slower strobe? I´m pretty sure I´m wrong. Do nitrate strobes work according to the two phase principle at all?

 

Here's a recent topic on nitrate strobes:

 

http://www.apcforum.net/forums/index.php?s...nitrate+strobes

 

Nice thread. Thanks Optimus!

[Mumbles]

That would be a good thread on this matter. The formula Optimus posted is one of the ones I was worried about. The other is very similar to the first two in the file Sambo posted, just using chlorowax.

[xetap]

A quick question:

 

How can you alter the frequency?

FWIW, in one of the tables of formulas for strobe stars, Kosanke states that altering the quantity of the 200 mesh magnalium will alter the strobe frequency. However, there's nothing to say how the rate is affected- less being slower or vice versa- though I suspect less = slower.

 

Quote: "Adjust strobe rate by using greater or lesser amounts of Mg/Al (200 mesh)"

 

I've never tried this, but I HAVE tried using finer than 200 mesh and this definitely does increase the frequency.

[pyropep]

I just wanted to report that we had superb results replacing HCB with 5% PVC and 2,9% Parlon in Hardt No.2. The result is a nice (cheap) green strobe with a need neither for AP nor for HCB. Nice find indeed.

 

I´d be really interested in those Sr(NO3)2-based strobes. Could you share them, Mumbles?

 

Thanks, and nice strobing everyone!

 

PVC is the best thing to replace HCB in strobes

Saran in only a couple percent will destroy the effect.

Rule of thumb is if formula calls for 12% HCB start with 5% - 7% PVC and go from there add more and more until you loose the strobe.

The duration can be adjusted by changing the Mg/Al mest size.

 

Pep

[AdmiralDonSnider]

PVC is the best thing to replace HCB in strobes

Saran in only a couple percent will destroy the effect.

Rule of thumb is if formula calls for 12% HCB start with 5% - 7% PVC and go from there add more and more until you loose the strobe.

The duration can be adjusted by changing the Mg/Al mest size.

 

Pep

 

 

Would you use a combination of PVC/parlon or just plain PVC?

[Mumbles]

I saw that same discussion over on passfire for the last few days, and was rather surprised to see the claims that PVC was the most suited toward strobes. I quoted the relevant sections from Eric Hunkins below, as well as relavent molecular formulas.

 

 

The reason HCB is used in strobes is because it is the best chlorine donor for them. The reason it is the best is because it is a poor fuel, not a good fuel. That is really the secret. For chlorine donors to work well in strobes they need to be poor fuels. A strobe is a delicate balance between two reactions. A good fuel will destroy the strobe and they will go into continuous burn. Saran is a better fuel, than Parlon, Parlon is a better fuel than PVC. So think the opposite, PVC is a better fuel for strobes than Parlon, Parlon is a better fuel for strobes, than Saran.

 

Adding only a couple of percent of Saran to strobe is enough to destroy it (or make it into a shimmering star which I do on purpose on occasion) If a formula calls for 12% HCB, start with 5% - 7% PVC and go from there. Add more and more until you loose the strobe.

 

I don't know off the top of my head, but a lot can be infered by it's structure (which I don't know and can't seem to find) If it is a simple benzine ring with lots of double binds it would be on the poor (good for strobe) side. If it is a chlorinated polymer it would be a better fuel (bad for strobe) depending on the substitutions.

 

Parlon - (C10H11Cl7)x (unsaturated)

PVC - (C2H3Cl)y (saturated and linear)

Saran - (C2H2Cl2)z (saturated and linear)

 

The first part makes perfect sense to me, worse fuels make better strobes. It's how PVC is the most suited that gets me. I agree the saran is the best fuel of the three, but I was always under the impression that PVC was in between parlon and Saran. Eric has far more experience with this than I.

[swervedriver]

Interesting, I read in Charlie Wilson's Chlorine Donors article (skylighter website) saran had a lower fuel value than pvc.

 

PVC (polyvinyl chloride) is another plastic that is used as a chlorine donor. PVC produces hydrogen chloride gas when it burns, which can be environmentally bad but pyrotechnically good. It does not contain as much chlorine as PVDC or Parlon, and also acts as a fuel more so than they do. It works very well as an adjunct chlorine donor in chlorate firework star compositions, and it is typically the least expensive compound of those discussed here. It also works well in combination with magnesium, where the HCl gas reacts with the metal oxides in the colored flame to improve the color.

 

And regarding Dechlorane-

 

Where a firework star composition actually calls for HCB, Dechlorane can be used as a substitute. Dechlorane in amounts higher than about five percent seems to increase the whiteness of the colored flame.

 

But since Eric has experienced the difference first hand in strobes between PVC Parlon and Saran, there you go...

[pyropep]

Where can Dechlorane be purchased? Edited January 20, 2010 by pyropep

[Mumbles]

Firefox had it the last time I checked, though there was a recent price increase. I believe Tim Seekon may also have it.

[drtoivowillmann]

I just reviewed a few nice strobe formulas without AP, e.g. Blesers green strobe or Hardt No.2 and wondered if one could simply replace HCB with Saran or Parlon, both showing a slightly lower chlorine content?

 

Or does the HCB fullfill yet another function than just giving chlorine to the flame, resulting in the necessity to use this particular salt?

 

Apart from strobe stars, can you replace it with Parlon or Saran?

 

 

Dear Admiral:

 

Typical for HCB ist extreme high clorine contents and extrem low carbon contents.

Neither has Parlon, nor PVC, therefore both are quite inferior in strobes to HCB.

 

But there is a good alternative: C-PVC. This is PVC the Chlorine contents of which is increased

by pos-chlorination, after its polymerization. It is a prime matter for electric isolation material.

It is available as a white, quite coarse powder. A famous brand of it is LUCALOR by Elf-Atochem

in France. Lucalor RB 67 S has about 67,5 % of its wheight in chlorine.]

 

I myself use it in my coloured srobes sucessfully.

 

Yours truely:

 

Toivo

[psyco_1322]

Another thing one might consider when pondering over all this is that PVC usually doesn't come as finely powdered as Parlon or Saran. If you have ever tried to roll stars with PVC, you would know that it like to separate out because of the larger sized particles. Larger particles would mean that it's combustion alone would be slowed down, possibly aiding in a successful strobe rate. It's pretty much the same principle as using coarser mesh metals in the strobes.