memo Posted July 6, 2016 Posted July 6, 2016 built a 3 inch 4 break with bottom shot it failed. a chain of events started when the tube blew the first 2 break lite and opened low . then the shell went into the ocean right at the surf line. found the shell and tore it apartthe spolette still had rammed powder in it. the water must had entered and put the fire out. only had 2 second delay. just bought the tube and had extra plug put in. it was buried in damp sand that was packed on the bottom and sides. the shell weighed 1130 grams and was lifted with my 2fa 70 grams . the only tube I am having trouble are the 3inch. how can I stop the tubes from blowing up. do I need to wrap the hdpe tubes in fiber glass ?. kinda at a loss. I really don't want to use steel pipe.memo
PhoenixRising Posted July 7, 2016 Posted July 7, 2016 Thanks you for sharing this. I am also interested in the limits of HDPE tubes as I had a little trouble with overheating them this 4th. Shot mostly comets this year and used only 2 tubes, just alternating tubes when one got too hot. But, I was curious as to what other options are out there for higher-pressure shots. I assume fiberglass would be the best option economically. Although, the thought of a flowerpot in fiberglass scares me, I assume the safe distance of 70 feet per inch of mortar should be a good start. Interested to see what others have to say here.
memo Posted July 7, 2016 Author Posted July 7, 2016 i really have no interest in the chiness cheapo tubes that are fiber glass. i think i am just pushing the limits a bit with my lift. memo
dagabu Posted July 7, 2016 Posted July 7, 2016 Both the clubs and PGI demand the use of steel for *multibreaks. DOM pipe isn't all that expensive and all you have to do is bury it to achieve some sort of safety from a gun blowing out.
memo Posted July 7, 2016 Author Posted July 7, 2016 dag I thought pgi was getting away from any steel tubes. all hdpe or fiber glass. can you wrap a hdpe tube in fiberglass. I think I read some where that it was tried. I wonder if it was a success memo
OldMarine Posted July 7, 2016 Posted July 7, 2016 (edited) How was the big gun Caleb made for someone on FW constructed? I think it may have been fiberglass over hdpe. I'm wondering if wrapping the guns in an aramid fiber would work better than glass.http://www.acpsales.com/OnlineStore.php?cat=4851 Edited July 7, 2016 by OldMarine 2
Mumbles Posted July 7, 2016 Posted July 7, 2016 Fiberglass is stronger than HDPE actually. At least the ones with the integrated plugs. I know one guy who swears by them for anything under 10lbs. I've never seen HDPE fail like that actually. Usually the plug is the weakest point and it cracks or blows out. I've honestly never seen an HDPE shell split like that without a flowerpot or salute go off in the mortar. I've shot 3" shells of that size without an issue from both fiberglass and HDPE without a problem.
dagabu Posted July 7, 2016 Posted July 7, 2016 (edited) dag I thought pgi was getting away from any steel tubes. all hdpe or fiber glass. can you wrap a hdpe tube in fiberglass. I think I read some where that it was tried. I wonder if it was a success memo Not that I know of, maybe they found a source for a thicker pipe? As far as I know, DR 7 (*333 psi) is the thickest and as you can see, the psi rating is pretty low. Where ASTM A-106 Grade B pipe is rated for *60,000 psi. Yes, the shrapnel is horrific but the strength for getting salamis out of the gun is something to consider. *Not an apples to apples measurement, the instant shock to the interior makes the two much closer to each other. Edited July 7, 2016 by dagabu
ExplosiveCoek Posted July 7, 2016 Posted July 7, 2016 You sure there was no weak point in the shell that allowed for a flowerpot? A shell break is a lot harsher on a tube than lift, normally.
memo Posted July 7, 2016 Author Posted July 7, 2016 the part of the shell in the picture is the bottom shot and the 4th break, the shell i tore apart was the third break break 1 and 2 went off in the air. so no flower pot or break going off in the tube. memo
memo Posted July 7, 2016 Author Posted July 7, 2016 How was the big gun Caleb made for someone on FW constructed? I think it may have been fiberglass over hdpe. I'm wondering if wrapping the guns in an aramid fiber would work better than glass.http://www.acpsales.com/OnlineStore.php?cat=4851oldmarinejust read up on this, sounds great to add to existing fiberglass tubes, it should hold up to multi breaks, cost isn't bad price. memo
jakespeed Posted July 7, 2016 Posted July 7, 2016 was there perhaps inadequate space between the shell & mortar? was the shell bent at all ?
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