dagabu Posted July 1, 2016 Share Posted July 1, 2016 No, vacuum is expensive an ineffective due to the cooling of the material. Heating it is also very ineffective in a vakuum, since it insulates very well. Bp will be dry after two days open drying, thats fast enought. All these drying technics, won't help at all, if you don't have a good mill. You don't need a drying box unless you can only produce at festivals like the pgi and need to stop and burn everything after a week. Hmmm, have you ever tried vacuum drying? I have a $40.00 vacuum pump and a pressure cooker that will dry dry out silica in an hour on a hot plate set to low. Heating is no problem at all. 1 Link to comment Share on other sites More sharing options...
Rushfire Posted July 2, 2016 Author Share Posted July 2, 2016 (edited) The vacuum drying went well and was to a nice damp consistency in about an hour. After granulating through an 8 mesh screen and placing in the drying box, I got granulated BP in 2 hrs! Loaded up 8 grams lift charge and a smaller 1 -3/4" dummy shell tonight and it fired about 200ft. Good enough I think, but could be better. I tried 10 grams with my larger 2-1/8" shells and fired only about 100ft. I am convinced it is because the rolled mortar tube dried unevenly, since the smaller tube is pvc, so I am rolling another one tonight, this time leaving it on the pvc pipe mold until it has dried to prevent warping. SO it looks like my problem was a combination of both warped mortar tube and not milling my BP long enough. I appreciate all the advice. There is another batch in the works milling from some fresh made pine charcoal I made last night which I hope will turn out even better. This time going to be more careful with the water lol. Edited July 2, 2016 by Rushfire 1 Link to comment Share on other sites More sharing options...
dagabu Posted July 2, 2016 Share Posted July 2, 2016 (edited) Bravo! Good for you, I hope you got something from this, along with a lifted shell! Edited July 2, 2016 by dagabu Link to comment Share on other sites More sharing options...
Zingy Posted July 2, 2016 Share Posted July 2, 2016 (edited) Hmmm, have you ever tried vacuum drying? I have a $40.00 vacuum pump and a pressure cooker that will dry dry out silica in an hour on a hot plate set to low. Heating is no problem at all. That is a really great idea, instead of heating the house, with the oven, on a hot summer day. Edited July 2, 2016 by Zingy Link to comment Share on other sites More sharing options...
MadMat Posted July 2, 2016 Share Posted July 2, 2016 (edited) I have posted this before, but since it came up.... You can get a makeshift vacuum pump from an old refrigerator or air conditioner compressor. I made my set up from an old window air conditioner that cost me... nothing! (neighbor was going to throw it away) Just a few notes on using one of these; there is, and needs to be oil in the compressor, and if you use it on things that can produce corrosive vapors, this oil needs to be changed regularly. Because of this oil, you need to release the vacuum from your chamber before turning off the pump. If you don't do this, your chamber (and anything in it) may get an oil shower. Lastly, I use regular mineral oil (available at the pharmacy). Measure how much oil you can drain out of the compressor, and replace with the same amount. Of course, you can buy compressor oil from an appliance parts store that carries refrigeration equipment/supplies, but this can be a bit costly. I have used this compressor for a number of years now and it still works just fine. Edited July 2, 2016 by MadMat Link to comment Share on other sites More sharing options...
dagabu Posted July 2, 2016 Share Posted July 2, 2016 Good point and add to that that compressor oil will gobble up water, miner oil takes up much less moisture. Link to comment Share on other sites More sharing options...
Rushfire Posted July 2, 2016 Author Share Posted July 2, 2016 (edited) True you can make a vacuum pump from those items, but vacuum pumps are actually pretty cheap now days. Just did a search on ebay and you can get a small 1/4 HP pump that reduces pressure to near 0 inHG for only 50$. A worth while investment I think. You would probably spend more on a vacuum chamber. By the way, I just tested the new gran BP I made last night and it works perfect. Makes a nice crisp boom and send shells soaring! Now I just need to get fuse timing right for the shell burst.. I have some "slow" fuse bought from cannonfuse, but it is still a bit too quick. Is there any way to slow down fuse without having to make some new slow fuse from scratch? Maybe coat it in something? And thanks dagabu, I have certainly learned a lot the past week. Edited July 2, 2016 by Rushfire Link to comment Share on other sites More sharing options...
Rushfire Posted July 3, 2016 Author Share Posted July 3, 2016 Success, figured out the problem with the shells going off in the air early. It seems the BP was lighting the fuse too close to the shell instead of the end of it. Fixed it by coating the length of slow fuse in hot glue to act as a protectant, leaving just the tip exposed. Link to comment Share on other sites More sharing options...
MadMat Posted July 3, 2016 Share Posted July 3, 2016 (edited) Using simple fuse for timing your shells isn't the greatest idea. You can buy time fuse which is specifically made for that purpose, but I personally don't care for it. You should look into making spolettes, instead of using fuse. They aren't hard to make and that's one less thing you will need to order from a supplier. Additionally, you add can aluminum or better yet, titanium to the powder in them to leave a spark trail. Though it's not as dramatic as a true rising effect, you can easily track your shell as it ascends. Edited July 3, 2016 by MadMat Link to comment Share on other sites More sharing options...
dagabu Posted July 3, 2016 Share Posted July 3, 2016 I limit my spolette use to canister shells myself, don't know if yours are balls or canisters but time fuse is exceptional in ball shells. Link to comment Share on other sites More sharing options...
MadMat Posted July 3, 2016 Share Posted July 3, 2016 Um yeah... I'm a can guy Link to comment Share on other sites More sharing options...
dagabu Posted July 3, 2016 Share Posted July 3, 2016 Link to comment Share on other sites More sharing options...
Rushfire Posted July 4, 2016 Author Share Posted July 4, 2016 Using simple fuse for timing your shells isn't the greatest idea. You can buy time fuse which is specifically made for that purpose, but I personally don't care for it. You should look into making spolettes, instead of using fuse. They aren't hard to make and that's one less thing you will need to order from a supplier. Additionally, you add can aluminum or better yet, titanium to the powder in them to leave a spark trail. Though it's not as dramatic as a true rising effect, you can easily track your shell as it ascends.Well it's not exactly standard visco fuse. It is timed to burn 40-45 seconds per foot, but the lift charge was igniting the fuse too close up to the shell I speculate since the problem was resolved with covering the fuse with glue except for the tip. Unless there is different fuse than this you were talking about? I'll definitely be looking into other methods as it would be very cool to have a spark trail, but it's good enough for now heh. Link to comment Share on other sites More sharing options...
dagabu Posted July 4, 2016 Share Posted July 4, 2016 Time fuse on the left, black match in the center and visco on the right: http://www.pyrobin.com/files/three%20fuses.jpg Link to comment Share on other sites More sharing options...
Rushfire Posted July 5, 2016 Author Share Posted July 5, 2016 Ah I see. I will have to look into getting me some of that time fuse! I have some blackmatch that I made last month but didnt find any use for it. It wasn't necessary to crossmatch these small size shells apparently, as they seemed to break the same with or without it. I ended up having time for making 21 1-3/4" shells and 15 2-1/8" shells for the 4th as well as 10 ball shell rockets. Everything worked perfectly, no bad eggs. The rockets I made were easily the best ones in our neighborhood gathering, blasting off and quickly cruising on up to about 300ft. The shells were all great too thanks to the new and much improved BP lift, breaking around 200ft. It was a great night indeed. It's pretty amazing how much prep time is required for making good fireworks hah. Even 2 weeks time of moderate-paced and 2 weeks of tireless prep everything was barely completed on time. Didn't have time to make any dragon eggs, firecrackers, or fountains. It was a lot of work but also a lot of fun and I have learned a lot. I think the way to go for the future is for fireworks to be a full-time, more leisurely paced hobby and to prep well in advance of holidays, having all materials already prepared in stock. Cheers Link to comment Share on other sites More sharing options...
pyronoob Posted July 6, 2016 Share Posted July 6, 2016 (edited) i use a HF ball mill and can mill 200g batches at 2 hrs. i alcohol granulate and get a regulation baseball from a 3"gun 300' on 1 oz of powder 4FA approx. 75/15/10 without binder.. Edited July 6, 2016 by pyronoob Link to comment Share on other sites More sharing options...
dagabu Posted July 7, 2016 Share Posted July 7, 2016 i use a HF ball mill and can mill 200g batches at 2 hrs. i alcohol granulate and get a regulation baseball from a 3"gun 300' on 1 oz of powder 4FA approx. 75/15/10 without binder.. PN, you can save a lot of money by doing away with the alcohol. You are in the middle of paulownia growing country, a simple TLUD and you should be able to fly that baseball for 9 seconds in .34 oz! Link to comment Share on other sites More sharing options...
pyronoob Posted July 7, 2016 Share Posted July 7, 2016 dagi haven't tried the paulownia charcoal yet...but you can bet im going to now. thanksPS how much binder should i use 3%? Link to comment Share on other sites More sharing options...
dagabu Posted July 7, 2016 Share Posted July 7, 2016 1-3% is the norm, depends on how durable you want the grains. Link to comment Share on other sites More sharing options...
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