M1l2n Posted January 5, 2012 Posted January 5, 2012 I have a bunch of 3” I.D. x 3 1/2” O.D. shipping tubes, spiral wound. I was thinking of coating them in wood hardener, installing a plug in them and use them for mines. I have made my own HDPE mortar tubes but never a paper one this size. Will these work? I know that the length of the tube will make a difference on it not blowing up because of the pressures and of course the lift as well. Any ideas? What would be a good length? Maybe a good starting lift formula, “1oz per pound”
dan999ification Posted January 5, 2012 Posted January 5, 2012 if it only has quarter inch walls i would not use it, it probably wont hold a plug well,and the walls may give, it depends how the hardener works out, for mines ten percent the content weight is a heavy lift and i use that for inserts, one ounce per pound is probably a better figure for mines with just stars, my card mortar is on nearly twenty heavy lifts and shows no signs of wear only minor singe's, but it does have 20mm walls and 5 inches of plugs 18 inches from the top to the plug is what i have, length does matter i find a tube this long to have some power but it depends what you want either straight up or spread low. dan.
M1l2n Posted January 5, 2012 Author Posted January 5, 2012 (edited) What if I rapped it with several turns of 90# Kraft paper? I know that is still a lot of work, I just hate to through out these nice looking tubes. Thanks for your help. I have a lot of space here so I can safely try it several times and see what or how they do. Oh and thanks for your tip on a starting lift load. Monty Edited January 5, 2012 by M1l2n
Mumbles Posted January 6, 2012 Posted January 6, 2012 You'll probably be fine with the walls. I've shot out of much less actually. I typically use 1/10th the weight of 4FA in 3" mines with a lift sabot. Then again, I like a good hard mine shot. I just don't find it particularly attractive to have stars or inserts drooping much.
M1l2n Posted January 6, 2012 Author Posted January 6, 2012 Thanks Mumbles, I read somewhere but I can’t remember where, of a guy that used pieces of broken Plexiglas melted in Lacquer thinner or acetone to seal and strengthen tubes. Has anyone tried it? If so, did it work well? Thanks Monty
Zingy Posted January 6, 2012 Posted January 6, 2012 Thanks Mumbles, I read somewhere but I can't remember where, of a guy that used pieces of broken Plexiglas melted in Lacquer thinner or acetone to seal and strengthen tubes. Has anyone tried it? If so, did it work well? Thanks Monty If you are worried about the tubes bursting, from a heavy lift charge, put a few layers of 2 inch wide filament strapping tape around the tubes, to about 6 inches above the wood end plug. The spiral wound tubes are much more likely to tear from the inside, after discharging a mine or shell. I have not tried plexiglass dissolved in lacquer thinner or acetone, but it sounds more like Skylighter's recommendation, on coating the inside of the paper mortar tubes, from tearing, by coating the interior with polyurethane, which works to a limited extent, and relative to the number of coatings.
Arthur Posted January 7, 2012 Posted January 7, 2012 My 3" mortars have walls about half an inch thick, the plug is polyester resin with sand filler, cast in situ and about an inch thick. The tubes were free from an industrial user of clingfilm.
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