JL96 Posted May 18, 2022 Share Posted May 18, 2022 (edited) Hi This composition is based of Pihkos KP Blue but with both the red gum and dextrin replaced with 5% PVB as a binder. The stars were rolled with pure alcohol and dried for a day. The silver glitter is winokur 9. https://youtube.com/shorts/dUu90vPxdxU?feature=share 66 Potassium Perchlorate15 Parlon14 Copper Oxide (Black)5 PVB Enjoy Edited May 18, 2022 by JL96 Link to comment Share on other sites More sharing options...
MadMat Posted May 20, 2022 Share Posted May 20, 2022 What is PVB? Link to comment Share on other sites More sharing options...
davidh Posted May 20, 2022 Share Posted May 20, 2022 https://ctpyro.com/content/polyvinyl-butyral-pvb-1lbs Link to comment Share on other sites More sharing options...
Carbon796 Posted May 21, 2022 Share Posted May 21, 2022 (edited) It can be used as a binder and fuel. Somewhat similar to Phenolic resin. It also has a similar slowing effect as PR. When used with BP type comps, iirc. When used in combination with PR and heat cured. It can add some toughness to the finished comet. So that it's less brittle than PR alone. Jim W (CTPyro) uses it as such, for his world record shells. It's been noted that it can have a whitening effect on blues. Specifically with blk copper oxide, as the color imparter. You'll often see it used in much lower percentages with blues, because of this. Edited May 21, 2022 by Carbon796 Link to comment Share on other sites More sharing options...
JL96 Posted May 21, 2022 Author Share Posted May 21, 2022 Yes I have tried a few blues with PVB but this is the deepest one so far, I prefer it as a binder as it is easy to work with especially when rolling stars, and dried fast and very solid stars. I'm 100% sure on this but it also makes stars more resistant to water? Link to comment Share on other sites More sharing options...
Carbon796 Posted May 21, 2022 Share Posted May 21, 2022 Doubtful, in theory it sounds plausible ( with various plastic/rubber type binders ). But the bound star matrix is usually still porous. I'm not sure about rolling, but with pressing you can probably get the pvb. Down to about 2%, make up the fuel value difference with sulfur. That would in theory, improve color depth. It looks like it's kinda fuel starved anyway. It is a good looking blue, better than I would have expected. Link to comment Share on other sites More sharing options...
JL96 Posted May 22, 2022 Author Share Posted May 22, 2022 Yeah I also had ideas about dropping the PVB down to 2% as it does burn very slow, but nit sure how much sulfur to substitute. I was also surprised with the colour considering the formula and other blues I have tried with perchlorate and PVB Link to comment Share on other sites More sharing options...
Carbon796 Posted May 22, 2022 Share Posted May 22, 2022 I'd just sub it 1:1 to start. To see if it's worth pursuing. I don't think I've seen an accurate representation. Of what pvb's fuel value might actually be. With parlon as the chlorine donor and primary fuel source. It's not surprising that you find it to be slow. Parlon is a sluggish "fuel" that works best in metallic fueled comps. Link to comment Share on other sites More sharing options...
Crazy Swede Posted May 22, 2022 Share Posted May 22, 2022 It can be used as a binder and fuel. Somewhat similar to Phenolic resin....I would say it is pretty far from being similar to phenolic resins! PVB is a lot less reactive when it comes to burning speed compared to phenolic resin (or red gum) but it is a much more effective binder and does not disturb the flame colour if used in small amounts. Using it as a primary fuel will probably seldom be effective but should instead be seen as a very good binder, especially if combined with NC lacquer! Link to comment Share on other sites More sharing options...
Carbon796 Posted May 22, 2022 Share Posted May 22, 2022 (edited) Swede, the only similarities I was implying. Was that they both can be used as binders and both have fuel value. If anyone has access to FW'ing. Swede ( if I'm remembering correctly, who you are, pretty sure I am ) has some of the best information/comparisons/test results of various additives in strobe star formulations. And highly complete, comparisons of chlorine donors in colored strobe, and colored star formulas, and others. Truly invaluable information, if your a builder. And primarily focus on colored effects, with an intent to tune/modify them.imho. Edited May 22, 2022 by Carbon796 Link to comment Share on other sites More sharing options...
Fliyud Posted May 25, 2022 Share Posted May 25, 2022 Hi This composition is based of Pihkos KP Blue but with both the red gum and dextrin replaced with 5% PVB as a binder. The stars were rolled with pure alcohol and dried for a day. The silver glitter is winokur 9. 66 Potassium Perchlorate15 Parlon14 Copper Oxide (Black)5 PVB Enjoy I am writing through an automatic translator. So he can distort the meaning of my question.Why is PVB needed in this composition if Parlon is an excellent binder. And then it includes 15%. Stars will be like a stone. Link to comment Share on other sites More sharing options...
Crazy Swede Posted May 25, 2022 Share Posted May 25, 2022 Hi This composition is based of Pihkos KP Blue but with both the red gum and dextrin replaced with 5% PVB as a binder. The stars were rolled with pure alcohol and dried for a day. The silver glitter is winokur 9. 66 Potassium Perchlorate15 Parlon14 Copper Oxide (Black)5 PVB Enjoy I am writing through an automatic translator. So he can distort the meaning of my question.Why is PVB needed in this composition if Parlon is an excellent binder. And then it includes 15%. Stars will be like a stone. With PVB you can use alcohol as a solvent, which often is preferred over acetone or MEK that you would need to dissolve Parlon. That helps a lot if you would want to roll stars and the moist composition will never be as tacky as when using Parlon as a binder. Link to comment Share on other sites More sharing options...
DecimusMaximus Posted April 2 Share Posted April 2 Anyone know a good cheap source for PVB? Ctpyro requires minimum 3lb order… Link to comment Share on other sites More sharing options...
Crazy Swede Posted April 2 Share Posted April 2 If you have a junkyard near by, you can always collect crushed windshields (not side or back windows) that you soak in ethanol or propanol. After decanting and filtering you have a solution of PVB. Link to comment Share on other sites More sharing options...
Arthur Posted April 2 Share Posted April 2 PVB is Poly Vinyl Butyral Among it's uses is the bonding layer in laminated glass (inc windscreens in cars). Google finds pictures of 12 kilo bags of powder but no seller. Link to comment Share on other sites More sharing options...
DecimusMaximus Posted April 4 Share Posted April 4 On 4/2/2024 at 12:55 PM, Crazy Swede said: If you have a junkyard near by, you can always collect crushed windshields (not side or back windows) that you soak in ethanol or propanol. After decanting and filtering you have a solution of PVB. Do I wait for the ethanol to evaporate or do I wait until the ethanol and PVB layer separate and suck it up with a syringe once it has separated from the settling? Link to comment Share on other sites More sharing options...
Crazy Swede Posted April 4 Share Posted April 4 I have not tried this myself but it might be possible to crash out the PVB from the alcohol solution by adding water. I see a big risk however of it forming a substance similar to sticky chewing gum. Turning it into a dry free-flowing powder might be hard for the amateur! Another option is using it as a solution. You must check its concentration though! Let it evaporate into a slightly viscous liquid that you test for dry weight, by letting a known weight of the solution completely dry out in a shallow and tared container that you weigh again afterwards. Then it is just simple math to calculate how much you need of your solution. This is probably only effective for cut and pumped stars since you want it in powder form for rolled stars. Link to comment Share on other sites More sharing options...
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