NDK
Cave Dweller 
Member since January 2009
Posts: 9,440
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Post by NDK on Apr 15, 2009 21:17:05 GMT -5
Chuck, I looked on mcmaster-carr, and you can get a 12" square piece of 3/8" thick PVC for $15.06 each. These could be cut to a disc, and cemented in the ends of your tube. This is called solvent welding, and it actually melts the ends together, basically the same principal as welding metal. I bet this would hold just fine to the pressure. I'd be willing to bet there's a plastic supplier local to you that may be a lower price too. Heck, I'd ask if they have damaged pieces for sale. If the corner's broke off, who cares, you'd be cutting it off anyway. lol Anyway, it's just a thought...  Nate Update : I just googled "minneapolis plastic supplier" and found a place in Eden Prairie called Plastics International. They sell the 3/8" 12x12 for $7.51 each. Here's the link - www.plasticsintl.com/index_other.php?cPath=37_38 |
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Post by Hard Rock Cafe on Apr 19, 2009 16:39:15 GMT -5
Thanks, Nate. If I end up rebuilding it again, I'll give them a shout.
I did as planned and used threaded rod through the lifters to pull the ends together, along with an extra piece of plywood on the bad end. It turns out that the bad end wasn't breaking due to pressure inside the barrel (either rock or gas): the leak had caused the plywood to start to delaminate.
I used extra waterproofing this time and caulked the ends. When I tightened up the threaded rod, caulk squeezed out of the sides. I'll let it cure a week before I fire it up again.
Chuck
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Post by Hard Rock Cafe on May 15, 2009 20:43:33 GMT -5
I think that the 50+ lb. load causes flexing of the pipe, so that the caulk did not maintain its seal. I was getting a leak between the end cap and the pipe. I have a 1/16" gap between the OD of the plug and the ID of the pipe in one area and that's where it leaked. If I had managed to cut the plug with a snug fit all the way around, I might not have gotten the leak.
So, today I cut a rubber gasket from an inner tube that I found in the woods while hounding. I put the gasket between the interior plug and the end cap. I had to torque the heck out of the nuts to get a decent seal without water seeping out. If I had more than 4 rods then it would have been easier.
It is loud and it's probably too dirty now to coat it with bed liner or tool dip. The good news is that it seems to grind a lot faster than my 15 lb. tumbler.
I'll let everyone know how it works out.
Chuck
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carloscinco
fully equipped rock polisher
Member since July 2008
Posts: 1,639
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Post by carloscinco on May 15, 2009 21:36:52 GMT -5
It only takes a little pressure against a disc as large as the ends of this barrel to exert a lot of force. If you can afford to keep the level below the centerline or be able to tilt this set up you can add a small vent in the center of one of the ends.
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Post by mohs on May 17, 2009 13:11:38 GMT -5
wow Chuck that's great ingenuity !
sorry for the problem
always the little tweaks !
good luck !!
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artofbali
off to a rocking start
Member since August 2009
Posts: 2
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Post by artofbali on Aug 2, 2009 23:20:00 GMT -5
Did you get this to work?
You could use a pvc cap for the no opening end, glue it on with pvc cement. On the other side create a lip on the inside of the pvc tube using cut-off pvc cemented into the ID of the tube, seal it well. Cut the cap to fit inside the tube Run the all thread thu the center of the tube with holes drlled in the center to run the all thread through. Tighten the cap using the all thread (add gaskets and a piece cemented on the outer wall of the tube to level the tube in the roller.
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flatlander
starting to shine!
Member since May 2007
Posts: 27
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Post by flatlander on Aug 3, 2009 11:47:02 GMT -5
The end caps are more expensive than the pipe, I paid $35.00 each for a couple of 12", but they fit inside, and leave the outside the same diameter. They do slide in about 6" and the pvc cement sort of melts the two pieces together, so nothing short of an explosion should loosen them up.
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Post by Hard Rock Cafe on Aug 3, 2009 12:47:58 GMT -5
So far, so good. I doubled up on the number of thread rods, so that I now have 8. That solved all leaking problems because the plywood caps can't flex now. I'm still using a 4" test plug in one end. The interior plastic is getting worn away, but it still works. I may end up switching to a metal one.
So, the ends look like plywood sandwich cookies with one side smaller in diameter than the other. The smaller diameter fits inside the pipe, then there's rubber gasket the same diameter as the pipe, and then the outer piece of wood that is also the same diameter as the pipe.
The inner piece of wood is getting worn away by the rock, so that will probably have to be replaced at some point. I may put a layer of sheet metal on it when I replace it.
Chuck
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lparker
fully equipped rock polisher
Still doing too much for being retired!
Member since March 2008
Posts: 1,202
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Post by lparker on Aug 6, 2009 19:06:40 GMT -5
You could try a two part epoxy coating on the ends, but would probably cost more than replacing the ends
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