stckmndn Posted June 20, 2011 Posted June 20, 2011 For making 3" rocket headers and 3" canister / cylinder shells... Is virgin kraft worth it? I've only ever used recycled 60 lb kraft and that heavy duty painters paper from Home Depot which I would estimate to be 70-75 lbs. Thanks.
Mumbles Posted June 20, 2011 Posted June 20, 2011 As with all things there is a gradient of quality. For instance, I'd not consider 60lb grocery bags a worth source of paper, but that which comes on rolls from Uline or hardware stores seems to be alright. I did notice some better breaks when I started using virgin kraft, but there was a big jump in quality of manufacturing and several other factors around the same time too. It's hard to tell really. When buying full rolls, the price difference on virgin vs recycled doesn't seem that great. For me it's worth it, but if I were to do things over again, I'd probably try to make recycled kraft work if only for ease of acquirement. I've actually been told that 50lb paper works very well on 3" shells, but it doesn't seem worth it to have all of that around. There are a few other applications for it, but not as many as for 30 or 70lb.
dagabu Posted June 21, 2011 Posted June 21, 2011 70#- 24" virgin kraft is $26.00 a roll at my source and Uline has the recycled for $25.00 a roll, both are in the Twin Cities where I live. 30# is where the big price difference is, $35.00 for virgin and still $25.00 for the recycled. Unlike Mumbles, I have found grocery bags to take paste well without failure so the kraft supplier may be different where he lives compared to here. -dag
stckmndn Posted June 21, 2011 Author Posted June 21, 2011 Thanks guys. I haven't been able to find 70 lb virgin kraft in a 24" roll. Only the big rolls. Must not have looked hard enough. Could you post a link, Dag?
dagabu Posted June 21, 2011 Posted June 21, 2011 (edited) 70#- 24" virgin kraft is $26.00 a roll at my source and Uline has the recycled for $25.00 a roll, both are in the Twin Cities where I live. 30# is where the big price difference is, $35.00 for virgin and still $25.00 for the recycled. Unlike Mumbles, I have found grocery bags to take paste well without failure so the kraft supplier may be different where he lives compared to here. -dag Sorry, I only resell kraft and I make $20.00 a roll in the process. A man has to make money for pyro somehow -dag Edited June 21, 2011 by dagabu
WonderBoy Posted June 21, 2011 Posted June 21, 2011 Berlau in the KC area has it, but 70# is about $10 more expensive than others. When I asked about it they claimed that this was because they had to get the 70# from a different source than the rest of their stuff. Kraft paper link
stckmndn Posted June 21, 2011 Author Posted June 21, 2011 (edited) Thanks Wonderboy. Shipping to me would be $25.26 for a grand total of $59.54. Considering how long it would last me for rocket headers... Maybe a friend will go in on it with me. BTW, which way does the grain run on a roll like that? Edited June 21, 2011 by stckmndn
stckmndn Posted June 21, 2011 Author Posted June 21, 2011 OK here's an unrelated topic though also related to excess. Who here happens to have a conical burr coffee grinder they use for pyro. I bet somebody does. I'd love to find one at a garage sale for grinding KNO3 just to say I did.
Mumbles Posted June 21, 2011 Posted June 21, 2011 I have 24" rolls, and while they're fine, I find I'd prefer 36" roll more and more. 24" doesn't make full turns on some sizes of shells. It's not the end of the world though, just personal preference. Any off cuts you need to make come in handy for rolling insert shell casings, nosings, lift cups, etc. If you look at the end cost of the paper, the extra $10 per roll for is really nothing. For 3" shells it's literally 1 cent per shell for recycled, and 1.5 cents for virgin. It really isn't anything. 1 roll lasts a very long time. I've had my rolls for over 5 years and have barely made a dent in them making a fairly sizable number of shells. I would say that virgin 70# will be of more use than virgin 30#. I use the 30# mostly for applications where strength is not an issue. I only really paste insert shells with 30#, and that does more fireproofing than anything. [edit] - the rolls are grain long IIRC.
dagabu Posted June 21, 2011 Posted June 21, 2011 I have three rolls of kraft, 50# recycled for packing, table covering, etc. 30# virgin for paste wraps on small canister shells, nosings, leave in cannula and fuse tubes. 70# virgin for shell casings, couplers, spolettes and rocket tubes. I like the 24" rolls for 2.5" canisters and if I had room, I would get a 36" and 48" roll of each the 30 &70 pound virgin kraft too. -dag
stckmndn Posted June 22, 2011 Author Posted June 22, 2011 I'll get the virgin kraft. Random question: Is there any practical use for corned BP in making rocket headers?
stckmndn Posted June 22, 2011 Author Posted June 22, 2011 Interesting. Could you point me to any reading material?
Mumbles Posted June 22, 2011 Posted June 22, 2011 Pyrotechnica IX and XI are pretty much the bible when it comes to canister shells. Passfire, and Hardt are also good resources. The following from Danny Creagan isn't bad either. http://www.wichitabuggywhip.com/fireworks/2inchsalami.html
dagabu Posted June 22, 2011 Posted June 22, 2011 Pyrotechnica IX and XI are pretty much the bible when it comes to canister shells. Passfire, and Hardt are also good resources. The following from Danny Creagan isn't bad either. http://www.wichitabu...inchsalami.html Thanks Mum! I have not read Danny's Page for some time now, what an easy method to make canisters. -dag
stckmndn Posted June 22, 2011 Author Posted June 22, 2011 (edited) Thanks Mumbles. I actually have scanned (read quickly) the Fulcanelli articles and the buggy whip tutorial. Time to go back and read them word for word. Don't remember reading about corned BP though I suppose it would make for a very solidly packed shell. Edited June 22, 2011 by stckmndn
dagabu Posted June 22, 2011 Posted June 22, 2011 Thanks Mumbles. I actually have scanned (read quickly) the Fulcanelli articles and the buggy whip tutorial. Time to go back and read them word for word. Don't remember reading about corned BP though I suppose it would make for a very solidly packed shell. It's referred to as pulverone in most places. Usually the word "corned" is referring to the breaking of pressed BP pucks to corn sized pieces. -dag
stckmndn Posted June 22, 2011 Author Posted June 22, 2011 Hi Dag: Yeah we were discussing corned and broken pucks. Have you ever used corned bp in headers?
r1dermon Posted June 22, 2011 Posted June 22, 2011 corning BP is just a method of achieving a particular grain size...since i dont have precise equipment, i crush large grains of BP into smaller pieces, and then sift them through screens of varying sizes. eventually i end up with 3-4 different grades of BP, and the flour is then wetted, pressed, and corned again once dry. you could use corned BP in headers. i generally prefer it for lifting shells, and meal coated rice hulls for break charges. using corned BP for "headers" as some sort of break charge would work (probably need to be well pasted/spiked) but would use substantially more BP than rice hull coated break.
dagabu Posted June 22, 2011 Posted June 22, 2011 Hi Dag: Yeah we were discussing corned and broken pucks. Have you ever used corned bp in headers? Mum can chime in here as well and explain with more detail the reasons why pulverone is used instead of corned BP but from my standpoint, corned BP is just to expensive and to powerful for use as a filler in shells ($1.00 a poind for pulverone v.s. $7.00 a pound for cheap commercial BP). I also find it to weight a lot more (25%?) then the same measurement of pulverone so that means that you have to use more lift (in bigger shells). The biggest reason that I have heard from others as to the "why" of using pulverone over corned BP is that is it "toilet flush" (thanks OG ) simple to make as all you do is mix the three chems, add 2-4% dextrine, add water and press it through a 1/4" screen and let dry. I personally let the whetted mix dwell for an hour and kneed it a second time before screening it so that the dextrine is fully activated before screening it. -dag
dagabu Posted June 22, 2011 Posted June 22, 2011 corning BP is just a method of achieving a particular grain size...since i dont have precise equipment, i crush large grains of BP into smaller pieces, and then sift them through screens of varying sizes. eventually i end up with 3-4 different grades of BP, and the flour is then wetted, pressed, and corned again once dry. you could use corned BP in headers. i generally prefer it for lifting shells, and meal coated rice hulls for break charges. using corned BP for "headers" as some sort of break charge would work (probably need to be well pasted/spiked) but would use substantially more BP than rice hull coated break. Corning Corning is a process in which black powder is compressed into cakes, crushed, and then screened into different size categories.[11] This process improves gunpowder's reliability by making its burn rate more consistent and inhibiting the separation of its constitutive components. Corning first compresses the fine black powder meal into blocks with a fixed density (1.7 g/cm³). The blocks are then broken up into granules. These granules are then sorted by size to give the various grades of black powder. In the United States, standard grades of black powder run from the coarse Fg grade used in large bore rifles and small cannon, through FFg (medium and smallbore arms such as muskets and fusils), FFFg (smallbore rifles and pistols), and FFFFg (extreme small bore, short pistols and most commonly for priming flintlocks). In the United Kingdom, the gunpowder grains are categorised by mesh size: the BSS sieve mesh size, being the smallest mesh size on which no grains were retained. Recognised grain sizes are Gunpowder G 7, G 20, G 40, and G 90. -WP-
stckmndn Posted June 22, 2011 Author Posted June 22, 2011 Hi guys, it was an odd question, I know. But let me explain why I asked it. In the Hummer thread the Tom R formula stated he used 7FA in his hummers. That suggested he may be using fine remnants of corned BP in his mix. I wondered why a rocket maker (who presumably may not even make lift for shells) would even have 7FA laying around. It seemed odd to me that someone would use corned BP over polverone as it would seem to be wasteful. Hope that clears things up. I do understand the difference as I use both.
dagabu Posted June 22, 2011 Posted June 22, 2011 (edited) Hi guys, it was an odd question, I know. But let me explain why I asked it. In the Hummer thread the Tom R formula stated he used 7FA in his hummers. That suggested he may be using fine remnants of corned BP in his mix. I wondered why a rocket maker (who presumably may not even make lift for shells) would even have 7FA laying around. It seemed odd to me that someone would use corned BP over polverone as it would seem to be wasteful. Hope that clears things up. I do understand the difference as I use both. LOL! I can answer that one for TR. TR buys 7FA (which is almost the same grain size as Meal-D and in some cases is sold as the other, see Crater Fireworks) for his time fuse to prime the fire end in the cap plugs as well as other things. In the below reply I made to Pyrochirs last year... "Chris, "FFFFg is about like 7FA. 7FA passes 40-mesh and is retained on 100 mesh. Meal D passes the same mesh 7FA does, but there is no smaller sieve on which it is retained - it includes all the dust. Fine meal passes 100 mesh, and extra-fine passes 140 mesh; both, like Meal D, include everything smaller." IMHO- -dag" This means that Meal-D, 7FA, meal dust will all work to make the same effect. BTW- TR indeed knows how to lift shells and has done so many times Pulverone also has dextrine in it, the dex will slow the burn. -dag Edited June 22, 2011 by dagabu
stckmndn Posted June 22, 2011 Author Posted June 22, 2011 Now that's a great answer. And Shirley you don't think I meant to imply TR does not know how to do anything he puts his mind to? LOL! For all I know there could have been some mad genius reasoning behind his methods. Thanks Dag.
dagabu Posted June 22, 2011 Posted June 22, 2011 Now that's a great answer. And Shirley you don't think I meant to imply TR does not know how to do anything he puts his mind to? LOL! For all I know there could have been some mad genius reasoning behind his methods. Thanks Dag. Roger, Roger, and stop calling me Shirley! -dag
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