viziers Posted August 6, 2012 Author Posted August 6, 2012 ok, so after very roughly (pieces were hard as a rock) rescreening the large batch of clumps with would'nt fit through a 4 mesh screen, I was able to get much more 4+fa and 5+fa I still have a bit of 3/4" worm pieces i'll prob crush up a bit later or use as is for filler. I did a little burn last night as well and I must say it burned unconfined with a bit of a snap type sound? Now as i'm new to building paper cans and cans in general, can I fill the remaining center (using the remining space after lining the can with 1/2" pumped stars) with my 4+fa.. I ask because after reading on the construction of a can they talk about using a canulle in the center up to 1.25" circular tube but with using the largest canulle for a 4" can there is still a bit of space between the canulle and the pumped stars hence why I want to make the complete center "the canulle".. Make sense? would I use a differentgrade of FA instead of the 4+FA? Thanks all,vizi
Potassiumchlorate Posted August 8, 2012 Posted August 8, 2012 Mumbles, what do you think of my grain size? Are they too small to lift a 5" or 6"? If I remember correctly, you said back on the UKPS board that you make your grains pretty small as well.
Mumbles Posted August 10, 2012 Posted August 10, 2012 I've been trying to find this post for a couple of days now to respond. PotassiumChlorate, I've used grains of approximately that size before, however normally use something in line with 2FA. Yours corresponds to about -16+50 mesh. I generally cut mine off coarser to -16+30 mesh or so. You can lift 5 and 6" shells with grains of this size. It however will be rather violent. I've done it and thought I've blown up mortars, and have seen others actually accomplish that feat. Given your affection for relatively sensitive chlorate and magnesium fueled mixtures, I probably wouldn't chance it personally and use something more in line with 2FA. If you're going to use that granulation, I'd cut back the amount. I used about 7.5% for a 6% shell, and this seemed way too violent IMO. Perhaps cut it back to 5-6% and see how that goes. It all depends on the quality of your black powder of course. I've been conversing with Vizi in private about this matter. Anyway to summarize if your comets don't fit snugly against the wall you can use chipboard shims to lock them in place. Alternatively you can back spin a few turns of paper or chipboard into the shell casing and effectively reduce the ID, making them fit snugly again. This second method is hard to get perfect, and may require some shimming anyway. The center if just using comets for the stars can be filled with a mixture of black powder and polverone to avoid using excessive amounts of expensive burst to totally fill the cavity. Some will fill the center cavity with BP on rice hulls or other sorts of media. I've done it and gotten away with, but it doesn't make me entirely comfortable. I prefer the shell to be totally solid and non-compressible.
Potassiumchlorate Posted August 10, 2012 Posted August 10, 2012 (edited) Well, my BP is pretty good but not top performance. I'll cut it down to 5% and try with dummies first. Btw, I don't mix chlorates with magnesium anymore. Edited August 10, 2012 by Potassiumchlorate
viziers Posted August 10, 2012 Author Posted August 10, 2012 So im making another batch of BP as I may need more to fill this 4" can that now weighs almost 1.25 lbs at the half full mark... vizi
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