Comps including Parlon and Dextrin

[stix]

I did some reading and was surprised that barium nitrate is quite toxic compared to strontium. I probably should be more careful. That red is a great red - It says "I'm red, and there ain't nothing you can deny about it!!".

 

However, the red mix didn't go all that smoothly, although the end result has worked well, I wasn't happy with my production of it. 22% acetone is way too much, with my chems anyway. It was way too sloppy. I had to wait for about 1hr until it became usable. All the while I was kneading it as it was drying on the surface - crunchy bits mixed in, perhaps being re-dissolved?

 

Not ideal, or the 'play dough' consistency I thought it might be. Needs work.

 

 

I don't usually quote myself, but necessary in this instance.

 

Cheers.

[rogeryermaw]

yessir we seem to be melting threads together...to stay on track here, yep 22% is way too much acetone.

 

my personal method is to mix my chems and screen together 3-4 times. after this mixing, i pour the composition into a cup and get my work space ready. i like to have everything ready to go since the solvent dries so fast. before solvent touches comp i have my wax paper rolled out, dowels the thickness i want to roll the patty to, prime box and all that.

 

pour an amount of comp onto the wax paper, dig a small hole in the middle and add acetone into that space and mix. when all the comp is wet i fold the wax paper over the comp and mash it flat. open it up and fold the patty 3-4 times and roll it into a rough ball shape. fold the wax paper over the ball, place dowels either side and roll the comp flat with a rolling pin or equivalent.

 

now to unfold the wax paper without the comp sticking to it i use a gentle tugging motion until the suface is exposed. dust with prime, fold the paper back over and roll the pin over it again to force the prime into the surface. do this on both sides and then cut. for cutting i use a long straight knife and keep a rag close by that you can dampen with acetone to wipe the knife clean between cuts. if you can get m.e.k. i hear the parlon won't stick so bad to your knife but i haven't used it myself.

 

one last black powder prime over this should do the trick.

 

i have never used a set amount of solvent for this, only worked by feel. one thing i noticed is that comps with red gum can be slightly thrown askew by over wetting with acetone. the dissolved red gum can rise to the surface of the comp and cause mixing to become uneven.

Edited September 8, 2015 by rogeryermaw

[carbonhalo]

Downunder, MEK is easy to get from any hardware, but it's known as "plumbers priming fluid for PVC pipes".

It usually comes dyed red, but is also available in a clear form.

(I haven't noticed any ill effects from using the red dyed type in rubber stars).

 

on a side note.... placing PVC pipe in MEK and leaving for a few days will cause the pipe to expand to 3 times its original size and turn it to a jelly like consistency. I expect this can be used as a cheap parlon substitute when this is unavailable.

[Mumbles]

Most hard PVC pipe will have a lot of fillers, like calcium carbonate and titanium dioxide. The calcium carbonate would affect the colors. Soft PVC tubing might work better, but you also need to account for plasticizers and other additives.

[stix]

Just finished making this green comp (1hr drying).

 

GREEN STAR

56 Barium Nitrate

17 Magnalium

17 Parlon

7 Red gum

+ Acetone to form a pliable dough.

 

I took Rogers advice and just kept adding enough Acetone until it formed a pliable dough. Much much better and easier to cut - so thanks for the tip.

 

I've just ground tested a couple of small pieces. In comparison to the red, at this point the colour isn't as deep - they don't burn as vigorously and have a slight yellowish tinge to the edge of the flame. I previously did a 'dry powder' test and the colour looked deeper (and it wasn't even dark enough outside). So I guess that would suggest it will perform better once fully evaporated? Not the same or consistent as the red though, which looked nice even when wet.

 

Anyway, as if I can make a scientific judgement after my first two rubber star comps. Although my feeling is that this green isn't going to get much better - I hope I'm wrong, only time will tell.

 

Looking at the formula, perhaps I should have added more redgum due to the omission of the dextrin - is it that critical?

Edited September 10, 2015 by stix

[PIL]

If you substitute red gum for dextrin, you will need extra oxidizer. A few percent of sulfur would improve the color.But too much will make it strobe.

The yellow tinge is caused by lampblack. The acetone that haven't evaporated may cause this. Try shooting the star out of the stargun . Atmospheric oxygen will kill the yellow tinge if your formula isn't too under-oxidized.

[rogeryermaw]

Red gum itself can add a tinge of red to the edge of the flame but not to worry. At around one hour of drying time I think what you are seeing is what the acetone does. It contains a lot of carbon and will mess with your fuel balance a bit. Let them finish drying and you should be a bit more pleased with them.

 

Also note that nitrate green just can't quite stand up to barium chlorate. That doesn't mean give up on it. But when you try them in a star mine from a distance, they will look much better.

[stix]

Thanks PIL, I've seen sulfur used in a another green comp, I didn't copy the formula though.

 

You may well be right about the lampblack due to the un-evaporated acetone. It's been another 1hr since my last test and I do believe the the colour has improved and the yellow tinge has subsided. So that's good. However, I still don't think the colour will ever have the depth of the red, so I should look at modifying the formula.

 

I have a star gun but not able to use it at the moment. However, I have the "stix flicka" which consists on a 2ft piece of "V" shaped aluminium with a slight depression in one end to hold the star. The star is lit with a jet lighter and flung about 30ft into the air. It gives a good indication.

 

I just tried this 10mins ago - not bad, but the green was a bit washed out. There were also orange balls falling off it, so clearly my formula is the problem, unless of course it changes tomorrow. I must have fluked the red, or green is a bit more fiddly to get right.

[stix]

Red gum itself can add a tinge of red to the edge of the flame but not to worry. At around one hour of drying time I think what you are seeing is what the acetone does. It contains a lot of carbon and will mess with your fuel balance a bit. Let them finish drying and you should be a bit more pleased with them.

 

Also note that nitrate green just can't quite stand up to barium chlorate. That doesn't mean give up on it. But when you try them in a star mine from a distance, they will look much better.

 

Thanks Roger, I'll see how it burns tomorrow - It looks like it's improving. The red at this stage is on another level. A tweak to the formula and that could help. Unfortunately I can't get any chlorates - I can get barium carbonate, chloride and chromate - not sure if they would be better than the nitrate.

 

But hey, I'm pretty happy with the green - not too bad, but it would be nice to improve it with what I have.

 

Cheers.

Edited September 10, 2015 by stix

[stix]

Ok, just tested the Green again using my "flick" method, and I'm coming to some conclusions (perhaps uninformed).

 

The green is nice - I like it, but there is an "orange coloured slag effect" that falls from it which I don't like - not good and very distracting. I tested the Red in the same manner and there is also the same orange slag, but not as bad.

 

So, I put forward two possibilities for what I see as a failure point (disregarding myself):

 

Possibility #1:

Using the "stix flicker" method is not good enough (25-30ft in the air). That is, it's able to show what a star (1/4") looks like falling through the air, whereas a star gun (or shell burst) will accelerate the star at great speed, and therefore burn the star properly given the added oxygen.

 

Possibility #2:

There is a chemical problem. Considering that I have the same issue with the red and green, I'll rule out Strontium and Barium Nitrate. The MgAl has to this point worked well for glitters, so I'll rule that out as well. That leaves Parlon and Redgum.

 

Parlon: perhaps I've accidentally been given PVC instead. Is there a definitive test that I can do to tell the difference?

 

Redgum: maybe I've been given powdered redgum wood instead of "accroides resin" - is there a simple test I can do?

 

The other common element is myself and my methods, but I find that harder to believe but of course, possible.

 

Cheers.

[rogeryermaw]

not too sure about how to test the parlon but the red gum should be easy. if it's wood meal, acetone would leach the resin out but leave the wood pulp behind when filtered. if it's just the resin, it will dissolve completely

[PIL]

Parlon dissolves in acetone but PVC doesn't. Slag is unavoidable because no powerful oxidizer like perchlorate is used.

 

Actually the slag won't affect the shell performance . Your retina will get used to the bright magnalium flame, so the dim slag will become 'invisible' .

[stix]

not too sure about how to test the parlon but the red gum should be easy. if it's wood meal, acetone would leach the resin out but leave the wood pulp behind when filtered. if it's just the resin, it will dissolve completely

 

Thanks Roger. I did that test and it dissolved completely (no need to filter). A nice deep reddish burgundy stain - no wonder the other artistic use for redgum powder is woodworking. Should have worn gloves though, what a mess!

 

Parlon dissolves in acetone but PVC doesn't. Slag is unavoidable because no powerful oxidizer like perchlorate is used.

 

Actually the slag won't affect the shell performance . Your retina will get used to the bright magnalium flame, so the dim slag will become 'invisible' .

 

Thanks PIL, but I'm not about to submit to "per/chlorate envy" just yet!!

 

I'm not being picky when I say "orange coloured slag effect". It's hard to describe - they are not as fine as a charcoal comp like TT, but more obvious and sparse.

 

Anyway, I dissolved some parlon in acetone as suggested and most of it dissolved very quickly, however there were some small white table sugar sized granules left (approx. 2 to 3%). I added more acetone and continued mixing, they still remained. I left it for a few minutes and mixed again - still there. I added some more acetone as it was becoming too thick. Left it for a few minutes, mixed it, still there. I continued this over a period about 15mins until eventually the white granules dissolved.

 

Now, I'm certainly no chemistry expert, but there is no way on gods earth, heaven or hell, that those granules are going to dissolve in the composition, even with my over-wetted +22% acetone. The 2 to 3% of possible impurities roughly equates to what I'm 'seeing' in the air.

 

I also did a 'dry test' and used my fingers to see if I could feel any lumps - no, it felt like the finest of talc.

 

So I tried MEK. The white granules appeared again - but after about a minute they dissolved. Well well well, there's surely something to be learned from that. Although I'm still not sure if these white granules would dissolve completely in the comp, even with MEK.

 

I wonder what the white granules are? I guess I could always make some sort of parlon+mek liquor, then add it to the comp. An annoying and tedious option, but doable.

 

Thoughts?

 

[EDIT] Just thinking, perhaps this issue would not occur with a dextrin+water bound comp.

Edited September 14, 2015 by stix

[PIL]

The'granules' should be Parlon lumps,they are too slippery to squash.

This situation is like dropping corn starch into boiling water.The thick paste covers the small lumps and keeps inside dry.The paste coating then dissolves gradually ，however it takes way more time.

If my guess is right, you don't need to use Parlon lacquer because Parlon has been finely dispersed in star comps.

Edited September 14, 2015 by PIL

[stix]

The'granules' should be Parlon lumps,they are too slippery to squash.

This situation is like dropping corn starch into boiling water.The thick paste covers the small lumps and keeps inside dry.The paste coating then dissolves gradually ，however it takes way more time.

If my guess is right, you don't need to use Parlon lacquer because Parlon has been finely dispersed in star comps.

 

Thanks PIL, but that doesn't really help. "you don't need to use Parlon lacquer because Parlon has been finely dispersed in star comps." well, no it hasn't been finely dispersed, because it leaves those little lumps and they never will dissolve in that composition. The acetone will evaporate way before it's done it's job. Unless you want to use shitloads of acetone over a long period. I don't.

 

The 'Parlon Lacquer' was just a "thought fart" and not an idea worth pursuing - although workable.

 

This has just solidified my reason for doing a dextrin + water comp. If there are impurities within the parlon, they will be mixed evenly throughout the composition in a fine powdered undissolved state (no lumps), leaving the dextrin to do it's work as the binder.

 

Thanks.

Edited September 14, 2015 by stix

[Col]

You can buy a lot of time by using a ziplock. Just run the chems through a screen a few times, dump into the bag, add acetone, close the bag. Squidge until homogenous, flatten patty inside the bag and cut it free when your ready to cut the stars. You can control the wetness of the mix by opening the bag.

[ZAIZAI]

I have tried the zip-lock-baggie-method, perhaps I used too much acetone but I had very little success with it. The wetted composition would become stringy and very sticky and cover the inside of the bag with a thick coating of composition. Sure, the rolled stars that eventually came out where brilliant (litteraly) but too much composition was left behind in the bag for me to use the method. Too much waste of chemicals.

I recently found that binding with alcohol-red gum works a treat when these stars are pressed or pumped, so I will be going with that method. Pumping is dire work though as the redgum will gall my brass pumps and the 8mm star pump is really hard to get a good grip on, especially with latex gloves...I really need to find some nitrile gloves that I can use. Not to mention a nice pillar press for my star plate...

[starxplor]

 

I have tried the zip-lock-baggie-method, perhaps I used too much acetone but I had very little success with it. The wetted composition would become stringy and very sticky and cover the inside of the bag with a thick coating of composition. Sure, the rolled stars that eventually came out where brilliant (litteraly) but too much composition was left behind in the bag for me to use the method. Too much waste of chemicals.

 

I recently found that binding with alcohol-red gum works a treat when these stars are pressed or pumped, so I will be going with that method. Pumping is dire work though as the redgum will gall my brass pumps and the 8mm star pump is really hard to get a good grip on, especially with latex gloves...I really need to find some nitrile gloves that I can use. Not to mention a nice pillar press for my star plate...

 

 

As for the gloves, pretty much any medical supply company, including pharmacy/chemist shops, carry them. Additionally, there are many places online. If you worry about getting the right size, ask your doctor's office for a sample pair of each size they have(usually 3 sizes in US). Most medical professionals are happy when patients take an interest in helping spread diseases... no need to tell them it is for pyro unless they specifically ask.

[ZAIZAI]

Oh, I know where to get gloves. Just the first batch I got was latex (yes, I feel stupid for ordering them) but I am too cheap to buy new gloves before I have used up my current lot. I have a chemistry degree and a chemical engineering degree not to mention that I work in a lab (day time)...so I know how to get hold of most of the stuff I require.

[stix]

You can buy a lot of time by using a ziplock. Just run the chems through a screen a few times, dump into the bag, add acetone, close the bag. Squidge until homogenous, flatten patty inside the bag and cut it free when your ready to cut the stars. You can control the wetness of the mix by opening the bag.

 

Thanks Col, that's the method I usually use for charcoal stars. I'm not saying it wouldn't be worth trying but my original red star mix was very much over-wetted, so I kept mixing it until it dried out enough to make a dough and cut - I would think that would have given the parlon plenty of time to dissolve completely, if it was ever going to.

 

I recently found that binding with alcohol-red gum works a treat when these stars are pressed or pumped, so I will be going with that method. Pumping is dire work though as the redgum will gall my brass pumps and the 8mm star pump is really hard to get a good grip on, especially with latex gloves...I really need to find some nitrile gloves that I can use. Not to mention a nice pillar press for my star plate...

 

Thanks Zai, I'll certainly try that method at some stage. I usually make a small 50gram comp, which is enough to cut 20-30 1/4" stars and pump 2 x 17mm (5/8th) comets. 5/8th size comet in a star gun is great to watch and that's about where I'm at. The stars are kept for future shells - if I ever get there.

 

I'd like to sort out the "slag" issue, or at least minimise it. So over the next weeks or so, I'll try these four methods:

 

• MEK instead of Acetone (parlon dissolves much easier in mek)
• MEK Liquor - then add the other dry components to it
• Dextrin as the binder (w/water)
• Alcohol, using Red Gum as the binder (pumped stars)

 

I'll be surprised if one of those methods doesn't produce a better burning comp with less slag - then again, I've been surprised before.

 

Cheers.

[Mumbles]

Troy Fish recommends a 90:10 mixture of acetone:alcohol for wetting parlon stars. I suppose MEK would also work in this same manner. It's supposed to cut down the gooey stickiness and stringiness of solvent wetted parlon.

 

When you say red gum/alcohol will "gall" your pump, what do you mean? I would assume you mean that it sticks and starts to sieze up the pump. I just wanted to make sure you weren't trying to say it's physically damaging the pump. Most of the time when I hear the word galling in relation to pumps, it's when coarse metal particles make their way between the plunger and the sleeve, and cause permanent damage.

 

I've always screened out the coarse parlon chunks from my star compositions. Then again, I also don't ever use acetone and parlon as a binder. The coarse parlon bit in normal stars tend to lead to this unwanted incandescent tail. I've always thought that when binding stars with parlon, you're basically regenerating coarse parlon by dissolving the finely powdered stuff. Not everyone making parlon bound stars gets this tail however. Given what was said above about the coarse stuff not dissolving overly well, I wonder if the coarse particles are still the problem?

[stix]

Troy Fish recommends a 90:10 mixture of acetone:alcohol for wetting parlon stars. I suppose MEK would also work in this same manner. It's supposed to cut down the gooey stickiness and stringiness of solvent wetted parlon.

. . .

I've always screened out the coarse parlon chunks from my star compositions. Then again, I also don't ever use acetone and parlon as a binder. The coarse parlon bit in normal stars tend to lead to this unwanted incandescent tail. I've always thought that when binding stars with parlon, you're basically regenerating coarse parlon by dissolving the finely powdered stuff. Not everyone making parlon bound stars gets this tail however. Given what was said above about the coarse stuff not dissolving overly well, I wonder if the coarse particles are still the problem?

 

Thanks Mumbles. The 90:10 mix is something I'll try if the other tests don't give positive results - that would make it test #5!!. I'll see how I go with what I've already outlined.

 

There are no coarse lumps in my parlon. It's a fine powder similar to flour or talc. One of the first tests I did after seeing the "golden dross" was to check the parlon. No lumps at all - nice and silky smooth.

 

Perhaps the reason for the "lumps" are as PIL suggested:

 

This situation is like dropping corn starch into boiling water.The thick paste covers the small lumps and keeps inside dry.The paste coating then dissolves gradually，however it takes way more time.

 

 

Maybe that scenario is correct. I've witnessed this phenomenon making pancakes.

 

It would be really good if someone else could do this test: A heaped teaspoon of fine powdered parlon, then add enough acetone until it becomes a liquid. By liquid, I mean add enough acetone until it's like the consistency of milk.

 

Do you see any small lumps formed, if so, how long before they dissolve completely?

 

Regardless, I'm going ahead with my tests. This is the same formula (post #30) except MEK instead of Acetone.

 

GREEN STAR

56 Barium Nitrate

17 Magnalium

17 Parlon

7 Red gum

+ MEK to form a pliable dough.

 

I'm making this comp now. All things going well, I'll report back in about 4hrs.

 

btw. I'm aware that this has probably all been done before. I'm just learning in my own way, with the chems that I have. This test is about the difference with that comp, ie. dissolving with acetone or mek.

 

Cheers.

Edited September 19, 2015 by stix

[stix]

Nice putty dough at this point - ready to cut soon.

[stix]

Nice cutting point reached. Easy to cut. Did a test and although still a bit moist, hardly any "dross". Will test tomorrow after at least 24hrs curing.

[rogeryermaw]

And this latest result is from m.e.k.? Looking forward to the follow up. Also going to give the 10% ethanol suggestion a try myself. Of course I'll report my results. Edited September 19, 2015 by rogeryermaw