Potassiumchlorate Posted June 16, 2012 Posted June 16, 2012 Except KeteN. Also, I know that I can synthezise it myself, but I prefer buying it, if possible.
Dean411 Posted June 17, 2012 Posted June 17, 2012 Except KeteN. Also, I know that I can synthezise it myself, but I prefer buying it, if possible. Looks to be just as difficult there as here in the U.S.A. It is actually quite easy to make just a pain waiting for it to dry out.I have made it 3 times now and its color quality is very goodI to would prefer to buy as opposed to making but using a old T-shirt to filter it saved a lot of time.
Bcorso85 Posted June 18, 2012 Posted June 18, 2012 There is a great article in one of the afn books on the process. I was going to start a topic about this. Dean, can you clarify the method and show us any problems, or possible dangers the article may have left out?
Potassiumchlorate Posted June 18, 2012 Author Posted June 18, 2012 There is an article in Pyroguide too. I have that issue of AFN too, by the way, but I don't have benzoic acid. The simplest way I could make it myself would be the "Pyroguide" method, i.e. by reacting copper sulfate with potassium benzoate.
FlaMtnBkr Posted June 18, 2012 Posted June 18, 2012 There is an article in Pyroguide too. I have that issue of AFN too, by the way, but I don't have benzoic acid. The simplest way I could make it myself would be the "Pyroguide" method, i.e. by reacting copper sulfate with potassium benzoate. Could someone tell me which AFN? Or detail the process? I have a bunch of benzoic acid just for this purpose but was later told it is the more difficult route. The copper sulfate and potassium benzoate is supposed to be pretty easy. My only problem is that every synthesis I have read seems to use different ratios of reactant chems.
Potassiumchlorate Posted June 18, 2012 Author Posted June 18, 2012 (edited) Best of AFN III. Page 98. The reaction is: 2H7H5O2(aq) + CuCO3(s) ---> Cu(C7H5O2)2(s) + H2O(l) + CO2(g). Twice as much benzoic acid as copper carbonate is used. 50 parts of water (at most), 12 parts of benzoic acid and 6 parts of copper carbonate. All of the benzoic acid and 1/4 of the copper carbonate should be added to the water in a glass jar. Stir. A thick slurry should form. The water is then warmed until bubbles of carbon dioxide appear. Stir until most bubbles are gone, i.e. the reaction is in principle over. Than add another 1/4 of the copper carbonate and repeat. When all copper carbonate is added and all bubbles seem to have disappeared, heat a little more to ensure complete reaction. Most of the water could be boiled off to speed up the drying time and make sure that the reaction is as complete as possible. Then dump the copper benzoate onto a mat of paper towels to absorb most of the remaining water. Air dry for several days or dry in an oven with good air cirkulation at 225oF. Pass the dry benzoate through a screen to break up all lumps. That's not literally what it says, but it's the essence of it. Edited June 18, 2012 by Potassiumchlorate
Mumbles Posted June 19, 2012 Posted June 19, 2012 I don't know if the copper carbonate and benzoic acid route is really any more difficult, but it is more time consuming and more messy IMO. When I followed the rough method in AFN, the product just didn't look as clean. This was probably just because I used slightly dirtier ceramic grade copper carbonate as a starting material. I use roughly the method outlined on pyroguide, though due us an excess of water. If you don't have fancy things like a stir plate, getting concentrated solutions isn't as easy. I also like using some extra water in order to make sure there is enough to dissolve the potassium sulfate. If you use saturated solutions, you'll have potassium sulfate precipitating. I've found alkali metal sulfates to be rather resilient and difficult to fully remove if they come out of solution first. 750I posted my method on passfire a few weeks ago, and can repost it here if anyone is interested. I use 750mL water per 320g K Benzoate, and 1000mL water per 250g copper sulfate pentahydrate. To keep all the potassium sulfate dissolved you need at least 1570mL, so I feel pretty safe at 1750mL.
Potassiumchlorate Posted June 19, 2012 Author Posted June 19, 2012 For my part it would be the copper sulfate-potassium benzoate route, though I'm pretty discouraged after trying to make strontium chlorate and strontium perchlorate with no success. In the first case I was working with a person considerably more skilled in chemistry, and in the second it should just have been a matter of reacting strontium carbonate with ammonium perchlorate. Both attempts failed.
Bcorso85 Posted June 20, 2012 Posted June 20, 2012 mumbles...... i have lost my passfire password Can you repost here? The AFN article suggested excellent blue using Copper Benzoate. If this is a simple process, thats not dangerous i would be happy to try it after the 4th.
Mumbles Posted June 20, 2012 Posted June 20, 2012 The most dangerous part about the procedure is the possibility to potentially ruin a significant other's metal kitchenware. Dissolved copper will attack aluminum and iron. I suggest plastic as much as possible. I always use distilled water. If you have clean water at home, you're welcome to try it, but I'd at least do the final rinsing with distilled. I've found triple scale or a kilo scale (based on anhydrous) is really convenient. It almost perfectly uses 2 full gallon jugs of distilled water, and fits nicely into a 5 gallon bucket. For a kilo pour out about 2 cups from one jug for the copper, and about one third for the potassium benzoate. It should leave you about a third of a gallon for rinsing. It's a little less than I recommend below for mixing, but it seems to do just fine. This assumes you start from the blue hydrated copper sulfate sold as an algicide, root killer, etc. I used normal potassium benzoate. Sodium would be a bad idea, as it will be difficult to wash out. I wouldn't waste good airmilled stuff on this procedure, as it all gets dissolved anyway. I picked up some cheap clumpy food grade potassium benzoate a few years ago that I use. You can find it in bulk to semi-bulk for a few bucks a pound. The copper is about $5-6/lb in 2lb containers, and gets down to $3/lb in 15lb pails the last time I saw it. If you can get stuff in reasonable quantities, you can make your own for about $6-8/lb approximately. Dissolve 320g of potassium benzoate in 750mL of water. Dissolve 250g hydrate copper sulfate in 1000mL of water. The amounts of water are not too critical and are overkill to dissolve the chemicals anyway. They are where they are to prevent potassium sulfate from precipitating later. Heating will help them to dissolve. If you don't mind waiting longer, you can mix the dry chemicals together and add the water, and stir/shake every so often. Make sure not to use metal containers or stirring utensils for the copper solution, or to stir the next step as they will be corroded. I generally used glass or plastic jars and/or plastic buckets depending on scale. After they're both fully dissolved mix them together and watch the pretty precipitate, let it sit for maybe an hour, stirring occasionally. The water should be nearly clear and colorless. I hear it sometimes changes colors some(probably hydration). Get a funnel, and filter your product through a cheese cloth or old t-shirt or something like that. If there is some getting through, allow the filtered liquid to settle, decant off most of it, and use a coffee filter to get what didn't get caught the first time. Rinse out your container with water to get everything out. Wash the solid with 2-3 portions of 300mL of water one at a time and let drain to help wash out residual potassium sulfate, should yield about 300g anhydrous or 360g of the hydrate. If you're doing larger quantities, a home-rigged vacuum filtration apparatus makes things go much faster. I can detail that if you're interested. It's pretty simple if you already have a shop-vac or something.
Bcorso85 Posted June 20, 2012 Posted June 20, 2012 Seems pretty easy. In a nut shell you are taking the chemicals, dissolving them, mixing them and straining off the crystals that have formed? Then washing/ drying the crystals. As far as heat goes. Should the liquid with the disolved chemical(s) ever reach a boil. or is that too hot? More like a simmer?
Mumbles Posted June 20, 2012 Posted June 20, 2012 It's pretty much as you describe. You don't actually need to heat anything. It will just accelerate the solvation of the two starting materials. The copper sulfate, especially if present as large crystals, can be kind of stubborn to dissolve. This is actually another reason the triple scale is nice. You can just add it to the jug and shake it every so often to speed things along. Heating to a boil will not hurt anything as long as you don't lose too much liquid.
Bcorso85 Posted June 21, 2012 Posted June 21, 2012 Thanks. Ill give it a try after the holiday. Have you ever made any blue formulas with copper benzoate?
AdmiralDonSnider Posted June 21, 2012 Posted June 21, 2012 (edited) I have once made the benzoate using copper sulphate and potassium benzoate. Although the starting quantities were small, it made a big jogurt-like baby blue mess, that had to be transferred into a huge bucket and washed several times, with consequent loss in yield. The final product was much less than it was expected to be and I have not yet cared to go through the process of dehydration. Given these obstacles and given the color quality is NOT said to be that good at all even with AP (see rec. pyro), I find it is not worth the hazzle. My 2 cents only... Edited June 21, 2012 by AdmiralDonSnider
Potassiumchlorate Posted June 21, 2012 Author Posted June 21, 2012 Hm, maybe I should follow the Admiral's advice. Chlorates are cheap and give good colours too. Bleser Aqua is a really good one, although it is based on barium chlorate=expensive.
Dean411 Posted June 21, 2012 Posted June 21, 2012 If you mill both chemicals you don't need to heat anything the potassium dissolves easily its the copper sulfate that's a PITA . As Mumbles said use plastic. The yeild might not be the greatest making copper benzoate but in reality for every 18 grams of benzoate you make you have a 100 gram final product. Since only 18% of new blue is copper benzoate.
Bcorso85 Posted June 21, 2012 Posted June 21, 2012 Thanks. Admiral---Would a high percentage chlorine donor like saran help the color? Chlorates im not sure about..yet. I have some potassium but I'm kinda "iffy" about using it.
AdmiralDonSnider Posted June 21, 2012 Posted June 21, 2012 (edited) Bcorso, I have not done a huge amount of testing with benzoates, so this would be speculation, but as far as I got things the experienced people on rec. pyro would much rather recommend using AP with ordinary chlorine donors, more common copper salts such as the oxide or carbonate as well as suitable fuels (hexamine for example) and would then tweak with the formula to optimize results, which are said to be as good as the older PG blues are said to be. In fact, copper benz seems to be one of the approaches to replace PG and one of many suboptimal as far as I´ve heard. But this is all irrelevant as I will be going to get my can of arsenic and make my own PG Edited June 21, 2012 by AdmiralDonSnider
Mumbles Posted June 21, 2012 Posted June 21, 2012 I've made some nice colors with it. I can't say that copper benzoate is superior to something like copper oxide or carbonate. The one advantage of it that I do sort of like is than I know that the material is pure. I'm a chemistry nerd, so if I can put those skills to use to make something, even if it will never pan out, I will. The AP and copper benzoate blue is not a typical dark cool blue. It's a brighter shade. I hear people call it "cop light blue" occasionally. Adding in a few parts saran as a chlorine donor does help it some. I originally made it to try to mess with blue whistle rockets, but it turns out that they don't actually whistle. It is nice for some things like fountains and the like where you can combine the colorant and a relatively energetic fuel.
Bcorso85 Posted June 24, 2012 Posted June 24, 2012 I've made some nice colors with it. I can't say that copper benzoate is superior to something like copper oxide or carbonate. The one advantage of it that I do sort of like is than I know that the material is pure. I'm a chemistry nerd, so if I can put those skills to use to make something, even if it will never pan out, I will. The AP and copper benzoate blue is not a typical dark cool blue. It's a brighter shade. I hear people call it "cop light blue" occasionally. Adding in a few parts saran as a chlorine donor does help it some. I originally made it to try to mess with blue whistle rockets, but it turns out that they don't actually whistle. It is nice for some things like fountains and the like where you can combine the colorant and a relatively energetic fuel. Thanks Chris,The whole reason I wanted to try Copper Benzoate is because I was under the impression it makes fantastic blues. As my favorite color i would like a non chlorate blue, also with out Paris Green. But who isn't I guess!
taiwanluthiers Posted June 25, 2012 Posted June 25, 2012 So whats so special about copper benzoate? Both copper sulfate and potassium benzoate are cheap, but the comp I saw with copper benzoate requires AP which I cannot get. Would good blue with copper benzoate and KP be acceptable?
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