BlueComet24 Posted June 8, 2016 Posted June 8, 2016 I've been looking for red star comps using strontium nitrate that don't use chemicals I don't have, such as KClO3, shellac, Mg/Al, Mg, or strontium carbonate. So far, I haven't found one that calls for only chemicals I have. Here is a list of my chems: BP chems, KClO4, strontium nitrate, dextrin, gum arabic, red gum, parlon, Al (Eckart 5413 and Alcoa 120), boric acid, Fe2O3, CuO, and a few others that shouldn't be relevant here. If anyone could share a good composition for red (or purple) stars using these chems, I would appreciate it.One of the closest I've found so far is this comp:Potassium perchlorate.............................44Strontium nitrate.................................31Red gum...........................................15Shellac (binder)..................................5PVC or saran .....................................8 or 7I was thinking that I could replace the shellac with either dextrin or gum arabic and the PVC/saran with parlon. I'm not sure how well it would work, though, as it might not be very vibrant, so I'm thinking I could add a couple percents of Eckart 5413 if needed.
lloyd Posted June 8, 2016 Posted June 8, 2016 Generally, shellac may be replaced "almost" 1:1 with red gum. There are a few rare blues that won't tolerate it, but nearly any other formula will. LLoyd
BlueComet24 Posted June 8, 2016 Author Posted June 8, 2016 Thanks. I take it that a PVC or saran to parlon substitution would also work?
lloyd Posted June 8, 2016 Posted June 8, 2016 Parlon can be a bit "ashy", and might need to be increased (some) to be equal, but I'd try it first at the same percentage. It's a RED, for heaven's sake. Even highway fusees (which have NO chlorine donor) burn "red enough"! <G> Lloyd
MadMat Posted June 8, 2016 Posted June 8, 2016 (edited) Here is another red comp that I use:50 Strontium nitrate18 Mg/Al17 parlon10 red gum5 dextrinThis is a nice red and the metal fuel gives it a "sparkly" effect.I have used straight Magnesium and bright flake and a combination of the two; all with success (more or less).I like it best with Mg only, but it might work with dark aluminum. Keep in mind that the oxides of these metals are different; Al = Al2O3, Mg= MgO, so a slight tweek is necessary to keep the fuel/oxidizer ratio the same. Edited June 8, 2016 by MadMat
OldMarine Posted June 8, 2016 Posted June 8, 2016 Here is another red comp that I use:50 Strontium nitrate18 Mg/Al17 parlon10 red gum5 dextrinThis is a nice red and the metal fuel gives it a "sparkly" effect.I have used straight Magnesium and bright flake and a combination of the two; all with success (more or less).I like it best with Mg only, but it might work with dark aluminum. Keep in mind that the oxides of these metals are different; Al = Al2O3, Mg= MgO, so a slight tweek is necessary to keep the fuel/oxidizer ratio the same. He doesn't have MgAl.
lloyd Posted June 8, 2016 Posted June 8, 2016 Thank you, Patrick. I was afraid - after some exchanges today in other threads - that I'd be taken as "too critical", even though the original post SAID "no magnalium". But you know... folks don't take kindly to being reminded of reality, sometimes! <G> LLoyd
MadMat Posted June 8, 2016 Posted June 8, 2016 I have used straight Magnesium and bright flake and a combination of the two; all with success (more or less).I like it best with Mg only, but it might work with dark aluminum. Keep in mind that the oxides of these metals are different; Al = Al2O3, Mg= MgO, so a slight tweek is necessary to keep the fuel/oxidizer ratio the same.He did say that he had aluminum.
OldMarine Posted June 8, 2016 Posted June 8, 2016 (edited) I'm learning pretty quick to read twice, comment once. Oh yeah, go back and edit when I see my glaring booboo! Thank you, Patrick. I was afraid - after some exchanges today in other threads - that I'd be taken as "too critical", even though the original post SAID "no magnalium". But you know... folks don't take kindly to being reminded of reality, sometimes! <G> LLoyd He did say that he had aluminum. ...and you've all seen those! Edited June 8, 2016 by OldMarine
Aspirina Posted June 9, 2016 Posted June 9, 2016 (edited) Here is another red comp that I use:50 Strontium nitrate18 Mg/Al17 parlon10 red gum5 dextrinThis is a nice red and the metal fuel gives it a "sparkly" effect.I have used straight Magnesium and bright flake and a combination of the two; all with success (more or less).I like it best with Mg only, but it might work with dark aluminum. Keep in mind that the oxides of these metals are different; Al = Al2O3, Mg= MgO, so a slight tweek is necessary to keep the fuel/oxidizer ratio the same.So, if I change the Mg/Al for only dark Al? as would be the formula? changes the ratio ? Edited June 9, 2016 by Aspirina
lloyd Posted June 9, 2016 Posted June 9, 2016 You CAN make the substitution and make it work. It will NOT be the same proportions. I'd suggest around HALF as much straight Al as MgAl, and of a MUCH finer grade, so that it won't make so much sparks. MgAl tends to 'brighten without much sparks'. Aluminum tends to "make sparks", unless quite fine -- then it doesn't so much 'brighten' as dramatically speed up the burn rate. And it heats things up to a degree that can denature colors (which is why I'd suggest 1/2 for substitution in an MgAl formula). LLoyd
BlueComet24 Posted June 9, 2016 Author Posted June 9, 2016 I just did some stoichiometry calculations and if you don't care about the changes that Lloyd mentioned, then you should use 87.67g of aluminum to replace 100g of 50/50 MgAl. I'm pretty sure that's right, but I had my chem final today, so I'm a bit chem'd out.
MadMat Posted June 9, 2016 Posted June 9, 2016 (edited) On a molar basis, it would be 1/6 less aluminum than magnalium. Edited June 9, 2016 by MadMat
BlueComet24 Posted June 9, 2016 Author Posted June 9, 2016 (edited) You seem to be forgetting to convert from moles to grams. By moles it would take one third less aluminum (or 1/6 less for substituting 50/50 MgAl), but by grams it would take 87.67% Al to replace 50/50 MgAl.Edit: I posted this right after you edited your comment. Now we seem to be in agreement. Edited June 9, 2016 by BlueComet24
MadMat Posted June 9, 2016 Posted June 9, 2016 (edited) I was about to calculate the adjust ment for the difference in molecular weight, but my keyboard freaked out and, of course you already did it BTW I rounded up to 90% Molecular weight of Al=26.98/Mg=24.31= .901 or 90% Edited June 9, 2016 by MadMat
AzoMittle Posted June 9, 2016 Posted June 9, 2016 (edited) Hey Blue, Here is what I have in my database. If you are willing to work with carbonates I can double this list, and if you are willing to work with magnesium/magnalium ( or substitutions of aluminum for it) I can give you 60+. I make no promises as to how these perform but they do meet your exact request: BigG's Red #1Red Gum, 5Parlon, 18Aluminum (Dark), 12Strontium Nitrate, 65 BigG's Red #2Red Gum, 3Parlon, 20Aluminum (Dark), 12Sulfur, 5Strontium Nitrate, 60 BigG's Red #3Red Gum, 8Parlon, 18Aluminum (Dark), 12Strontium Nitrate, 62 DeadFX Red Star #1Hexamine, 1.5PVC, 1Aluminum , 1.5Strontium Nitrate, 5.5Potassium Perchlorate, 1.5 DeadFX Red Star #3Hexamine, 1.5PVC, 1.5Aluminum , 1.5Potassium Perchlorate, 7 Edited June 9, 2016 by AzoMittle
BlueComet24 Posted June 9, 2016 Author Posted June 9, 2016 Thanks, Azo. BigG's comps seem a bit heavy on the parlon for a strontium nitrate comp, but I might try something based off of them.
AzoMittle Posted June 9, 2016 Posted June 9, 2016 (edited) edit: No problem Blue, I'm glad to help! If dumping a bunch of formulas like this is against forum policy for any reason please let me know! Here are the purples/pinks/violets I was able to find that matched your bill (same disclaimer applies, and again I have plenty more if you're willing to work other chems, the mgal is in easily half to three quarters of them): Non-metallic Go-GettersDextrin, 5Copper (II) Chloride, 7 (II)Charcoal, 15Sulfur, 8Ammonium Perchlorate, 70 Davis' Violet Star Pg.85Copper Oxalate, 5Shellac, 3Potassium Perchlorate, 12 Joel Baechle's Lavendar Star PCH #1Potassium Benzoate, 4Red Gum, 2Hexamine, 6Parlon, 20Copper Oxide, 3Aluminum , 7Strontium Nitrate, 8Potassium Perchlorate, 50 Joel Baechle's Mauve Star PCH #1Red Gum, 16Hexamine, 4Copper Oxychloride, 5Strontium Nitrate, 37Potassium Perchlorate, 38 Joel Baechle's Violet Star PCH #1Stearin, 2Potassium Benzoate, 5Red Gum, 8Dextrin, 2Lactose, 5Parlon, 5Copper Oxychloride, 15Ammonium Perchlorate, 40Potassium Perchlorate, 20 Joel Baechle's Violet Star PCH #2Potassium Benzoate, 5Strontium Oxalate, 5Vinsol resin, 1Dextrin, 4Chlorowax, 9Copper Oxychloride, 15Potassium Perchlorate, 59 Joel Baechle's Violet Star PCH #3Potassium Benzoate, 4Red Gum, 2Hexamine, 7Parlon, 20Copper Oxide, 10Aluminum , 7Strontium Nitrate, 15Potassium Perchlorate, 25 Chempac Pink #1Charcoal, 3Sulfur, 4Strontium Nitrate, 40Potassium Nitrate, 10 Chempac Pink #2Red Gum, 2Dextrin, 1Charcoal, 2Sulfur, 4Strontium Nitrate, 30Potassium Nitrate, 10 Chempac Pink #3Red Gum, 2Charcoal, 2Sulfur, 4Strontium Nitrate, 30Potassium Nitrate, 6 Davis' Rose Star pg.85Strontium Oxalate, 1Lampblack, 1Dextrin, 1Potassium Nitrate, 6Potassium Perchlorate, 12 Joel Baechle's Magenta StarRed Gum, 2Hexamine, 8Parlon, 20Copper Oxide, 10Aluminum , 10Strontium Nitrate, 30Potassium Perchlorate, 20 Joel Baechle's Maroon StarLampblack, 2Red Gum, 14Vinsol resin, 12Dextrin, 4Charcoal, 3Potassium Perchlorate, 55 Joel Baechle's Salmon Star #2 PCHLampblack, 4Red Gum, 4Parlon, 18Copper Oxide, 1Aluminum , 15Barium Nitrate, 5Strontium Nitrate, 45Potassium Perchlorate, 5 Weingart's Pink Star Tableau Pg.61Charcoal, 4Sulfur, 5Strontium Nitrate, 48Potassium Nitrate, 12 Weingart's Pink Star Tableau Pg.61Red Gum, 3Charcoal, 1Sulfur, 2Strontium Nitrate, 16Potassium Nitrate, 4 Weingart's Pink Star Tableau Pg.61Red Gum, 4Dextrin, 1Charcoal, 2Sulfur, 4Strontium Nitrate, 36Potassium Nitrate, 14 Weingart's Pink Star Tableau Pg.61&134Shellac, 3Calcium Sulphate, 4Potassium Perchlorate, 16 Edited June 9, 2016 by AzoMittle
BlueComet24 Posted June 9, 2016 Author Posted June 9, 2016 If dumping a bunch of formulas like this is against forum policy for any reason please let me know!It's fine by me, and part of what I wanted. I find it odd that very few purple/violet comps use strontium nitrate AND copper oxide (and not anything I don't have or can't substitute). It seems that they're either CuO and SrCO3 or Sr(NO3)2 and any copper salt except CuO.
AzoMittle Posted June 9, 2016 Posted June 9, 2016 Well, I have plenty of formulas that DO use SrN and CuO together, but they pretty much all contain magnalium. Magnalium can be expensive and it is a PITA to coat but it opens up a whole lot of options. Let me know if you want me to send you the ones that contain MgAl.
BlueComet24 Posted June 9, 2016 Author Posted June 9, 2016 For some of them I might be able the substitute the MgAl with Eckart 5413 Al, but if it's more than about 5%, I don't know that it'd work too well. I don't want to work with MgAl yet because it's a PITA and more hazardous than Al, but I'm sure I will eventually. I really want to make dragon eggs one of these days, plus the many other things MgAl is useful for. I wonder if coating the MgAl could be made easier. I've read that camphor will sublime and coat metal (steel, but it may work with MgAl) in a protective coating. It may work to put some camphor granules in with some MgAl and leave it in a sealed container for a while.
AzoMittle Posted June 9, 2016 Posted June 9, 2016 It's not terrible, but it is annoying imo. Weight out your metal and 5% of that in potassium dichromate, heat up a little water and add the dichromate, slowly add water until it is all dissolved, mix in your metal, dry the mixture; dichromate is toxic so gloves, respirator, etc are necessary. From Shimizu's FAST, boiled linseed oil works great except for ammonium perchlorate and sodium carbonate: http://i.imgur.com/REtO107.pngmirror: http://imgur.com/REtO107
MadMat Posted June 9, 2016 Posted June 9, 2016 (edited) I don't find coating my metals with dichromate that much of a PITA. Adding 5% dichromate to the dry metal and then adding a small amount of boiling water is pretty easy and it dries fairly rapid (if placed in a sunny spot and stirred regularly).As far as straight Aluminum "washing out" the color as Lloyd stated, I have noticed, in my experiments with substituting metals in this formula, that I have gotten "orangy-reds" with straight aluminum. It is a somewhat pretty color in it's own right, but definitely not a true ruby red. Like I previously stated, I prefer using straight magnesium, and I feel it is worth the extra effort making it safe. Sorry about the confusion in my posts about the substituting numbers last night. while writing my post, my cat decided he wanted some attention and jumped up right on my keyboard. That particular keyboard has some problems right now. Edited June 9, 2016 by MadMat
Davidg1 Posted June 9, 2016 Posted June 9, 2016 Why coat magnalium? Surely it is much less reactive than pure magbesium and aluminium.
BlueComet24 Posted June 9, 2016 Author Posted June 9, 2016 Magnalium is less reactive than magnesium, but more reactive than aluminum. Aluminum forms a protective oxide layer (called a "passivation layer"), while magnesium does not. I believe that magnalium partially forms one, but it's not enough. Looking at Shimizu's tests, we can see that uncoated magnalium will be attacked dangerously by hydrochloric acid, ammonium perchlorate, potassium chlorate and perchlorate, and nitrates. Thus it must be coated to ensure safety while handling and storing compositions.
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