Dextrin & SGRS's

[chemtech89]

I'm hesitant on starting new topics since a lot can be learned just by reading. However, I searched for an hour to find what I'm looking for but to no avail. This is not the Dextrin vs. SGRS thread. Yes they are both binders and people use them for slightly different reasons. Non of the reasons I've found answers my question so I thought id ask while I wait for the next batch to dry.

 

Recently Ive made Fire Fly cut stars with SGRS and it did not have the effect it should have had regarding the Al. It had a great fire dust with the pine charcoal but there was very few silver/white sparks, and not the fire fly type. In the past when playing with the Tiger Tail formula, I noticed something I found interesting. Specifically, when comparing TT made with red gum 10% and 5% spherical Ti(-40+300) and TT with 6% dextrin and 5% Ti(-40+300), the red gum version burned with of course the typical fire dust (brighter with red gum but not my point) and silver/ white sparks consistent throughout in the tail as one might expect. However, the dextrin version actually had that specific fire fly effect, not great but much different when comparing the two just by switching between those two binders. So, I'm wondering if the dextrin is necessary to cause that fire fly effect.

 

Has anyone else noticed this or tried making FF with SGRS? Also, I'm not ruling out some kind of error on my part in my manufacturing process because it made these cut stars not it the conventional sense. I only dampened the mixture (not too wet) as you would when pumping stars/ comets. Then, pressed (by hand and after with a rolling pin) the mix into those plastic florescent light guards you see in office buildings to make nicely even squares. Also, I did use denatured alcohol with water by the way. Thought I should mention it since using SGRS.

 

On a side note I've been wondering the same about glitter formulas. Any experience/ ideas/ difference in the effect and/or tail?

 

Not concerning the strength of the binders, what performance differences have you had between the two?

 

Thanks!

 

[MikeB]

Firefly can be a touchy formula and the effect is dependent upon the type of aluminum you are using. I have not used sgrs to bind it with, but if I did I would use plenty of water to activate the binder. And eliminate the alcohol which impedes the sgrs. It has been suggested by a notable person to use dextrin and dampen the comp with a solution of wheat paste.

[Mumbles]

I'm about 90% sure that these firefly stars were made with SGRS:

 

There are two types of firefly aluminum going around. One is made my transmet and is 10-12 mesh and looks like cut up foil. It's a bit on the thicker side IMO. It can be made to work, but I had more trouble with it. There is another made by Eckhart of model number 41813G. It's sometimes called -20 mesh or +20 mesh depending on who is selling it.

 

Transmet: http://www.skylighter.com/mall/product-details.asp?id=14

Eckhart: http://www.skylighter.com/aluminum-flake-20-mesh.htm

 

I've had more luck personally with the Eckhart version. The transmet product, while great, can be a little tricky to get to light in my experience. From hearing from others, the Transmet version is a little touchy to get to light. If you look at Shimizu's firefly formulas, you'll notice that he added a few parts strontium or barium sulfate to emulate a higher ash charcoal to get his Al to light. It should be noted that the Eckhart version has more of a variation in particle size. If you want the best effect, you need to screen out anything that passes 30 mesh to prevent it from lighting too early. If you watch the video of my mine, you can see a few glitters come on a little too early.

 

I really only make stars bound with water. I have noticed and exploited the pseudo firefly effect found with titanium. I use it in my brocade formula. http://www.amateurpyro.com/forums/topic/6983-brocade-stars/

 

I honestly wouldn't be entirely surprised to find that water is required for both the glitter and firefly effect. They're purported to go by similar mechanisms. Non-aqueous binders seem to kill this effect partially or entirely with glitters. There are a few that seem to work, but most of the more common ones like red gum do not do the trick.

[psyco_1322]

Your method of manufacturing is pretty normal, nothing you're doing should affect the effect.

 

I wouldn't be surprised about the water being somehow needed either. I made a batch of stars that should have made a firefly effect, bound with NC, and they exhibited hardly any firefly twinkles. I have made some brocade type stars with NC and they worked fine, although that's not quite the same since they use FeTi, not Al.

 

I still don't believe that alcohol reduces the effectiveness of water binders. I've used 25-50% alcohol solutions and never had issues, stars still come out hard as rocks. I hear people talk about it, but I can't recall anyone actually reporting issues because of it.

[Potassiumchlorate]

Your method of manufacturing is pretty normal, nothing you're doing should affect the effect.

 

I wouldn't be surprised about the water being somehow needed either. I made a batch of stars that should have made a firefly effect, bound with NC, and they exhibited hardly any firefly twinkles. I have made some brocade type stars with NC and they worked fine, although that's not quite the same since they use FeTi, not Al.

 

I still don't believe that alcohol reduces the effectiveness of water binders. I've used 25-50% alcohol solutions and never had issues, stars still come out hard as rocks. I hear people talk about it, but I can't recall anyone actually reporting issues because of it.

 

Dextrin doesn't function that way, but IMHO SGRS does.

 

According to Shimizu SGRS burns slightly slower than dextrin, but I don't think it burns considerably slower.

 

Charcoal stars are extremely depending on being "activated" by water, by the way.

[psyco_1322]

...

Charcoal stars are extremely depending on being "activated" by water, by the way.

 

And what makes you think this? Seems to be charcoal stars work just fine with out the need to be wetted by water.

[Potassiumchlorate]

And what makes you think this? Seems to be charcoal stars work just fine with out the need to be wetted by water.

 

No, the oxidizer must be incorporated into the charcoal. Try TT stars without wetting them really good, for instance. It won't work.

[psyco_1322]

No, the oxidizer must be incorporated into the charcoal. Try TT stars without wetting them really good, for instance. It won't work.

 

What do you consider "really good" and what is it like when it's not working? Is a crumbly damp mix, suited for pumping comets enough water? The original poster mentions red gum to work with TT, and even states it produces a brighter effect.

[Algenco]

Firefly is bound with wheat paste is the way to go. mix the paste and add to comp, makes a nice rubbery patty.

 

I like SGRS for certain comps, dextrin or wheat paste for others.

 

The only drawback for SGRS IMO is that it takes more water and time to activate

[dan999ification]

i think dissolving the oxidiser no matter how you do it should give very similar results, i made quite a few tt stars without the wet proscess pumped with minimal water to aid drying, they work but the tails are sparse with heavy grained firedust, i discovered after re milling a driven in batch of cut stars that were over wet the effect was far superior with very fine grained firedust and suprisingly longer tail with less fallout.

 

The only dissapointment ive had with glitters ( ralphs and win 19 ) is that dissolving the nitrate using too much water or using milled nitrate gives a short tail with almost no glitter in it or falling from it, obviously minimal water is preferable as is a not binding too hard using sgrs which requires more water than dextrin could possibly make it worse, having never used sgrs i could well be wrong,

 

While this is the relevant thread, can sgrs be subbed for dextrin in comps that are heavy in al or c, it doesnt seem to affect charcoal streamers, silver wave calls for sgrs but with the amount of water needed and activation time i would think dextrin is more suited to rolling these stars, unless its just not sticky enough, would dextrin alter the effect? Even if i added more to compensate for its weaker properties?

 

I would also assume that comps that are designed to have a tail should give up the tail producing material quite quickly unless very coarse to prevent it being burnt up on the star and not be bound too hard to aid this ( why they normally use dextrin) very fast burning comps like silver wave would benefit from harder binding effectivly slowing the burn rate (from edge to centre ) and the tail production.

glitters bound with red gum would im sure exhibit the same problem as other tailed stars not giving up its tail quick enough and burning it off on the surface, (im suprised it doesn't affect tt's tail only colour) unless the red gum interferes with the relationship between the sulphur and metal.

 

Dan.

 

Edit: i realise now i should have started my own thread, sorry chem for not being much help and possibly de railing yours.

Edited January 16, 2013 by dan999ification

[Potassiumchlorate]

What do you consider "really good" and what is it like when it's not working? Is a crumbly damp mix, suited for pumping comets enough water? The original poster mentions red gum to work with TT, and even states it produces a brighter effect.

 

My experience is that they won't adhere and won't burn well, if made without water or without enough water.

[psyco_1322]

My experience is that they won't adhere and won't burn well, if made without water or without enough water.

 

So that answered nothing. I'm curious about your experiences.

 

What is the effect of a TT star that isn't burning well? Does it not have any tail, does it not light, does it fall to the ground glowing?

 

How much water is needed, in your experiences? No water means a non-aqueous binder. A slightly dampened mix suitable for pumping comets, would be about minimal water you could use to bind the comp. Is that going to be enough water, or not?

 

 

Dan, if you could/would use proper grammar, it would make your posts a lot easier to read. It literally takes twice as long to read your posts because of that randomness. Things like capitalizing I's and the beginning of sentences. Also using periods where a sentence should end, and not using commas to produce 3 lines of run on sentences. I'm not trying to be rude, I don't know you, but it would make a world of difference to your posts, and the outlook that people have on you. Remember that the only thing we have to judge you by is the words you type here.

Edited January 16, 2013 by psyco_1322

[Potassiumchlorate]

 

I have made several attempts to make good TT stars, but they wouldn't adhere properly. I added +10-12% of water - didn't work.

 

If you try to light TT composition that hasn't been wetted, it will hardly burn. I don't see what's so controversial with this, I think even Shimizu himself mentions it.

[chemtech89]

Thanks for the replays guys! Youve made some good points.

 

I used the Eckart 41813G labeled +20mesh but did not screen out the fines so im suspecting those were the few silver sparks i saw and the larger peices werent getting hot enoguh to ignite. I mentioned the alcohal because most say it should not be used with SGRS however i was under the impression it would degrade the binding qualities, which i did not have an issue with. Also, it was not a high percent but just engough to brake surface tension. Next, i will deffenetly try using the wheat paste. In that respect should water not be used? I assume the water in the wheat paste will activate the binder, correct? Algenco you mention "FF bound with wheat paste" makes me think you did not use any binder like dextrin, just the paste. Is that right? I used the FF formula found on skylighter:

Chemical Parts % Factor 16 Oz 450 Grams Potassium nitrate 55 48% 0.48 7.7 oz 216 g Charcoal, airfloat 29 25% 0.25 4 oz 112.5 g Charcoal, 80-mesh 11 10% 0.10 1.6 oz 45 g Sulfur 9 8% 0.08 1.3 oz 36 g Firefly aluminum 5 4% 0.04 0.6 oz 18 g Dextrin 5 5% 0.05 0.8 oz 22.5 g Water +41 +36% +0.36 +5.75 oz +162 g

 

and of course used SGRS and less water as mentioned in table.

 

In the past with once again during another experiment, i used 10% red gum as the binder in D1. It still had the glitter effect but was nowhere near as bright or dence as the normal formula.

 

Hoping someone could very breifly share how they make their wheat paste assuming it not the powdered form. Ive heard of some people not boiling it and that doesnt seem right to me. I know this has been covered many time but each mixture and making procedure ive read varies. I just want somthing solid to start from and from someone that actually used it in the aplicate im going to use it for. Also, what your shelf life like?

[chemtech89]

The table did not come through, sorry about the mess. I tried to edit but the computer im using wont let me at this time.

[psyco_1322]

 

I have made several attempts to make good TT stars, but they wouldn't adhere properly. I added +10-12% of water - didn't work.

 

If you try to light TT composition that hasn't been wetted, it will hardly burn. I don't see what's so controversial with this, I think even Shimizu himself mentions it.

 

Sounds like you had some binder issues, that much water should have worked fine. Maybe you forgot the binder.

 

 

 

 

For wheat paste, this method is what I use and makes a decent amount of paste, just scale to your needs.

 

1) Boil 3 cups of water in a soup pot.

2) In a blender, mix 3 cups of cold water with one cup of flour.

3) Pour the flour/water mixture from the blender into the boiling water, stirring as they mix.

4) Keep stirring the mixture, making sure the paste does not burn and clump up on the bottom of the pot. At a certain point the paste will begin to get noticeably thicker. The longer you cook it, the thicker it will get.

5) Once the paste has reached the desired viscosity, let it cool and use it right away.

Edited January 16, 2013 by psyco_1322

[dan999ification]

interesting how d1 works with red gum who'd a thunk it.

 

Psyco: while i was offended at first i see your point and never gave my writing much thought......ever, theres a reason i work with my hands.

I'll make no excuses, but please if you must judge me use my work as a reference not my english skills.

You should see me with a pen

 

Dan.

[Col]

 

For wheat paste, this method is what I use and makes a decent amount of paste, just scale to your needs.

 

1) Boil 3 cups of water in a soup pot.

2) In a blender, mix 3 cups of cold water with one cup of flour.

3) Pour the flour/water mixture from the blender into the boiling water, stirring as they mix.

4) Keep stirring the mixture, making sure the paste does not burn and clump up on the bottom of the pot. At a certain point the paste will begin to get noticeably thicker. The longer you cook it, the thicker it will get.

5) Once the paste has reached the desired viscosity, let it cool and use it right away.

 

I do mine in the microwave, saves on the washing up It comes out super smooth so you dont need to sieve it

[psyco_1322]

I do mine in the microwave, saves on the washing up It comes out super smooth so you dont need to sieve it

 

Interesting, can you give us a run down on how you make it?

[Mumbles]

Psyco, I find that ratio of flour to water gives paste that is good for pasting paper. However for making comets and wetting stars, a thinner variety is desired. I usually cook it as you describe, and water it down later if I am going that route. I do typically use the powdered stuff that one just mixes with water. 6 or 7:1 water to powdered paste is just about right for breaking in paper. About 10:1 is good for wetting composition.

 

When wetting a composition Chemtech, you do use both the wheat paste wetting agent and dry dextrin in the composition. The comets come out really hard. Wetting with wheat paste is also very helpful when dealing with compositions containing high amount of flake aluminum.

 

Dan, I really do have to agree with Psyco here. If you actually want to be taken seriously, you have to step it up. Running things through a spell checker to start with would be an enormous improvement. I have actually found myself simply ignoring anything you've been writing recently just because everything is so egregiously poorly written and riddled with horrid spelling and terrible grammar and sentence structure. If I have to actively work at trying to decipher what you're trying to say, I can only assume that it's probably of the same quality of how it was written. Using your work to judge could be an issue as I don't recall ever really seeing anything you've built.

[marks265]

Adding a percent of sodium or potassium benzoate will help to keep the paste. I've kept paste in a fridge while I was pasting each day without any benzoate. When completely done with all layers I would then toss the left over paste.

 

Commercial paste with benzoate I have had on a shelf at room temperature for a few months and it is still good.

 

Mark

[chemtech89]

I just finished the next batch of FF but this time I screened the flake and used 6:1 wheat paste. I didn't see the new posts until now. The ratio of paste wasn't a problem but I will go a little thinner next time like you suggest mumbles. Also, thanks for the clarification with just adding the paste into the composition, which is what I figured but wanted to make sure. In a few days when they dry I will take a video of a star gun test with the old and the new stars so you all can see the difference. Hopefully it will be significantly different which I think it will be.

[Col]

Interesting, can you give us a run down on how you make it?

I start with 30g wheat starch and 300ml water in a large 2L microwave proof jug, Mix the starch with 50ml of the water first then add it back to the 250ml.

Cook for a minute at a time on full power (800w microwave) stirring in between. Reduce the cooking sessions to 30 seconds towards the end as it can boil over. Mine takes 6 minutes 30 seconds from cold.

[Potassiumchlorate]

I made some simple and unscientific tests. I mixed SGRS with the water/alcohol solution (75/25), that I use for my dextrin. When it dried it got pretty brittle. Then I tried with pure water. It took considerably longer time to dry, but it became rock hard.

 

This is where it becomes a problem with handrolling with SGRS: you get "raspberries" due to the slow activation of SGRS. If you try to speed it up with alcohol, you will lose the superior adhesion capacity.

Edited January 25, 2013 by Potassiumchlorate

[a_bab]

There's something I didn't see mentioned here: SRGS is best for charcoal stars, as it will allow the particles to split properly on burning, creating a thicker firedust. All the stories concerning TT stars coming back on earth as glowing embers are related to dextrin unually.

 

A special charcoal star, with black locust charcoal for instance, that creates sparks which would just seem to hang in air forever can't be made with dextrin - in that case SRGS is the only option.