superspike23 Posted July 29, 2012 Posted July 29, 2012 hi,I found the cardboard tubes in my work. they seem very solid. here is a picture with the dimensions. http://img11.hostingpics.net/pics/831382001.jpg What type of shell should I build to make it work with the tube? what dimention and what weight?
taiwanluthiers Posted July 30, 2012 Posted July 30, 2012 Maybe you can reinforce the tube with more layers of paper if you're unsure... as for shells whatever that will fit with a small gap when finished.
FlaMtnBkr Posted July 30, 2012 Posted July 30, 2012 That looks about right for festival ball shells which are usually called 1.75". Mortar tubes are usually 1.91" ID if I remember correctly. A 2" shell is a hair over 5 cm so wouldn't work. For a small festival shell the wall thickness should be plenty. Just need to put a plug in and you're ready. You can also treat them a couple different ways to make them last longer. I have instructions for a method which the guy claims to have tubes 25 years old that are still going. It used waterglass and another chemical. Let me know if interested or just put something that is waterproof and will absorb into the paper.
superspike23 Posted July 31, 2012 Author Posted July 31, 2012 That looks about right for festival ball shells which are usually called 1.75". Mortar tubes are usually 1.91" ID if I remember correctly. A 2" shell is a hair over 5 cm so wouldn't work. For a small festival shell the wall thickness should be plenty. Just need to put a plug in and you're ready. You can also treat them a couple different ways to make them last longer. I have instructions for a method which the guy claims to have tubes 25 years old that are still going. It used waterglass and another chemical. Let me know if interested or just put something that is waterproof and will absorb into the paper.yes I am interested in the method Can you give me information? I will plug the hole with quick-setting plaster.
FlaMtnBkr Posted July 31, 2012 Posted July 31, 2012 I'm not sure how well plaster will hold up. I think you would at least need to drill some holes and insert a dowel or two for the plaster to hold on to. Can you get a 5 cm hole saw that you attach to a drill? A wood plug glued and screwed in place is best. Can you get calcium chloride and waterglass (sodium silicate)? Those are the 2 chemicals needed but I will have to look up the process. I bet PVA glue (Elmers or wood glue) mixed with a little water to thin it out and painted on the tube would work almost as good. Once you get a plug in you can pour the mix in and turn the tube to coat it, and then turn upside down to catch the excess to use in the next tube. Then turn it right side up to dry so any excess will pool on the plug and fill in any cracks. I used wood glue to seal all the layers together at the end of a tube and it is holding up great.
ryanlg95 Posted August 1, 2012 Posted August 1, 2012 I have several cardboard tubes 2" in inner diameter and about 1/4" thick and they work perfectly for 2" ball shells. For an end plug I just got a hole saw and drilled through a 3/4" piece of MDF and removed the circle piece of wood from the hole saw and hammered it into the end of the tube and secured it with 4 nails/tacks. I've launched probably 15 shells from one of them and the only sign of wear is the inside of the tube is slightly burnt/singed. No banana peels or bulges in it.
manmfireworks Posted February 1, 2013 Posted February 1, 2013 I would make sure the plug is at least 1 1/2 inch thick. I try not to use cardboard tubes. I only use HDPE tubes. I know of a really good place to buy HDPE tubes from. www.manmfireworks.com Happy ShootingBe Safe
nater Posted February 1, 2013 Posted February 1, 2013 There is absolutely nothing wrong with cardboard mortars, except the poster above vends HDPE, and has posted nothing except for links to his website. I agree with FlaMntBkr that plaster would not be the best material to make a plug. For a 2" mortar, I would use a 2" wood plug screwed or nailed into the mortar. Plaster or clay is often used to plug cakes, but those aren't meant for more than one shot. I've also seen plaster plugged mortars in consumer shell kits, but again those are only meant for a few shots.
mikeee Posted February 2, 2013 Posted February 2, 2013 If you need to plug the tube you should use a wooden plug inserted in the tube and secured with screws and adhesive.Another option would be use a thick square block of wood and use the correct size hole saw to cut 1/2" deep circular slotinto the block and use an adhesive to glue the tube into the slot. I have also use fiberglass resin left over from projects I wasworking on and poored it in the bottom of the tubes with screws already screwed into the tubes.
Niladmirari Posted December 7, 2013 Posted December 7, 2013 Not to produce threads write here.Mortar digged in the earth. Only for sustainability? Or else to mortar is not cracked?I never digged. But now preparing 12-inch bowl. And I'm afraid that the pipe from the shot can crack. Is this true?
Mumbles Posted December 7, 2013 Posted December 7, 2013 I'm not only partly sure what you're asking. Burying mortars provides some additional strength to the walls. More importantly it helps to contain any pieces if the mortar should fail.
Niladmirari Posted December 7, 2013 Posted December 7, 2013 Thank you!How deep dig in? 1/3 or 2/3 of the height?
Mumbles Posted December 7, 2013 Posted December 7, 2013 The regulations and guidelines I'm familiar with from different countries and different organizations tend to say minimally somewhere between 2/3 and 3/4 buried. Having seen a variety of mortars fail, there is definitely a benefit to having more than half buried. 1
Niladmirari Posted December 11, 2013 Posted December 11, 2013 It's me again. What should be a gap (interval mm) between the ball and the 12-inch mortar?
FlaMtnBkr Posted December 11, 2013 Posted December 11, 2013 You can probably have a quarter inch (6 or 7 mm) gap on a large shell like a 12" and be ok. Probably wouldn't go much more than that. Are you using a commercial ball shell casing?
Niladmirari Posted December 11, 2013 Posted December 11, 2013 You can probably have a quarter inch (6 or 7 mm) gap on a large shell like a 12" and be ok. Probably wouldn't go much more than that. Are you using a commercial ball shell casing?Тhanks for the answer. I use: http://savepic.su/3988768m.jpg
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