gt3073b
off to a rocking start
Member since September 2020
Posts: 11
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Post by gt3073b on Sept 10, 2020 16:50:18 GMT -5
My daughter LOVES rocks, and I'm building a tumbler for her birthday. I've been scouring the forum trying to understand why most of the 6" PVC barrels use a reducer to a 4" Fernco cap rather than just using a 6" Fernco cap on the end. Is it because the center of the cap wears out?
If so, does it wear faster than the solvent weld end cap on the other end or the shoulder of the reducer? I would think the flexible material would resist wear by reducing the pressure at the wear point.
Could I use some HDPE (maybe from a cheap cutting board) inside the Fernco to prevent the wear?
Thanks for the help, Bryan.
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jamesp
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Post by jamesp on Sept 10, 2020 20:40:24 GMT -5
The highest point of wear is at the center of the closed end. You can add a plug or circle of say HDPE before assembly to protect the center point but it may capture coarse grit particles behind it that may let go during the 220-500-1000 or polish steps. the shoulders of the 4 to 6 reducer wear quick too.
A Fernco requires a band clamp. So the reducer is used to clear the Fernco's band clamp.
I build my barrels out of an HDPE reducer(4 to 6 and 6 to 8) butt welded to an HDPE end cap. Fernco. This is bulletproof. HPDE welds are top notch connection.
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gt3073b
off to a rocking start
Member since September 2020
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Post by gt3073b on Sept 13, 2020 17:09:35 GMT -5
Thank you! HDPE is out of my price range, but I will go the traditional route of using the reducer to keep the wear off the Fernco.
Bryan.
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Post by manofglass on Sept 13, 2020 17:31:30 GMT -5
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jamesp
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Post by jamesp on Sept 14, 2020 6:59:07 GMT -5
A compression plug is a great idea manofglass. Blocks wear right wear it happens, center of domed cap.
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Post by manofglass on Sept 14, 2020 9:03:10 GMT -5
Test plugs wear it takes a long time before they wear out And test plugs are cheap I have never had a end cap wear out yet
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gt3073b
off to a rocking start
Member since September 2020
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Post by gt3073b on Sept 14, 2020 12:25:15 GMT -5
What fitting is the test plug in? I don't see the neck of a reducer. Will the test plug expand all the way up to the coupling ID or only the pipe ID?
Thank you all for the great ideas!
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gt3073b
off to a rocking start
Member since September 2020
Posts: 11
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Post by gt3073b on Sept 14, 2020 12:34:21 GMT -5
Looking at it again, did you just drill a 4" hole with a hole saw in a regular end cap?
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Post by manofglass on Sept 14, 2020 13:06:24 GMT -5
Looking at it again, did you just drill a 4" hole with a hole saw in a regular end cap? Just drill a 4” hole in the cap with a 4” hole saw The test plug expands and plugs the hole I use channel lock pliers to tighten the nut down To stop leaks
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Enigman
starting to spend too much on rocks
Member since December 2013
Posts: 163
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Post by Enigman on Sept 16, 2020 19:47:32 GMT -5
Just out of curiosity, how long could a PVC barrel POSSIBLY last for tumbling? I would think that the first run of rocks with 60/90 grit would chew a hole in the barrel.
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Post by manofglass on Sept 16, 2020 21:48:29 GMT -5
Just out of curiosity, how long could a PVC barrel POSSIBLY last for tumbling? I would think that the first run of rocks with 60/90 grit would chew a hole in the barrel. Abrasive ceramic will wear the can thin in a week But grit doesn’t hurt it I run 46/70 grit And pea gravel
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gt3073b
off to a rocking start
Member since September 2020
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Post by gt3073b on Sept 20, 2020 22:49:35 GMT -5
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Post by manofglass on Sept 21, 2020 8:28:59 GMT -5
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gt3073b
off to a rocking start
Member since September 2020
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Post by gt3073b on Sept 21, 2020 16:22:02 GMT -5
I wish those came in 6", especially at that price! I guess I'll be the guinea pig.
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gt3073b
off to a rocking start
Member since September 2020
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Post by gt3073b on Sept 23, 2020 21:11:25 GMT -5
I just received 2 pieces of the Sioux Chief T-Cone fittings from www.supplyhouse.com/Sioux-Chief-882-ST602-6-Flush-Head-T-Cone-SCH-40-Pipe-Barrel-Plug?gclid=EAIaIQobChMI5LzQgar56wIVQdbACh0NVwHAEAQYASABEgK4VvD_BwE (from my post above) and some 6" schedule 40 solid core pipe. I'm still acquiring parts for the rest of the tumbler, but these fittings look good. The rubber is about 11/16" thick and has a coarse tapered thread cut on the inside diameter. The red plastic (ABS I think) has a matching tapered thread on the outside and is dished (nearly hemispherical) inside, which should keep it from wearing too quickly. Even at just hand tight, it seems to lock up nicely on the pipe ID, so no other fittings are necessary, and nothing extends radially beyond the pipe OD. If this works, the cost of the caps is quite a bit less than 2 solvent weld PVC caps and a 4" test plug or a cap, bushing, and a test plug. I'll be sure to update the thread once the machine is up and running. Thanks for all the help!
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jamesp
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Post by jamesp on Sept 25, 2020 3:28:18 GMT -5
This is a 6 inch sch 40 PVC barrel after about a year running at higher rpm's and very coarse SiC in step 1 only. The equation is simple, faster speeds and coarser silicon carbide = fast barrel wear and faster rock shaping. I now use more wear resistant HDPE barrels for aggressive tumble shaping. Anyway the faster wearing zones in a tumbling barrel are clearly apparent. Sch 40 PVC pipe can be split like piston rings and slid into the inside of the barrel to increase thickness. The 4 inch pipe section can be removed and replaced with effort. The end cap can be made thicker by inserting a circle cut from a HDPE butcher block in before glueing the end cap on. All this is labor intensive. I found life easier just making an HDPE barrel because of their durability when running fast with aggressive abrasives. Simply weld a reducer to an end cap, cut 4 inch snout down to 2 inches long. 30 minute build... And bit the bullet and bought a lifetime supply of 1000 pounds of coarse SiC(Carbolon SC) for $450 instead of 20 x 50 pounds at $90/50 pounds = $1800 or more. Power bill much cheaper running at higher speeds too due to fast tumble shaping times. Increasing a rotary tumbler's speed does not increase the power usage much. It is the 2 month shaping runs that uses lots of power. 6 inch sch 40
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jamesp
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Member since October 2012
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Post by jamesp on Sept 25, 2020 3:43:23 GMT -5
I just received 2 pieces of the Sioux Chief T-Cone fittings from www.supplyhouse.com/Sioux-Chief-882-ST602-6-Flush-Head-T-Cone-SCH-40-Pipe-Barrel-Plug?gclid=EAIaIQobChMI5LzQgar56wIVQdbACh0NVwHAEAQYASABEgK4VvD_BwE (from my post above) and some 6" schedule 40 solid core pipe. I'm still acquiring parts for the rest of the tumbler, but these fittings look good. The rubber is about 11/16" thick and has a coarse tapered thread cut on the inside diameter. The red plastic (ABS I think) has a matching tapered thread on the outside and is dished (nearly hemispherical) inside, which should keep it from wearing too quickly. Even at just hand tight, it seems to lock up nicely on the pipe ID, so no other fittings are necessary, and nothing extends radially beyond the pipe OD. If this works, the cost of the caps is quite a bit less than 2 solvent weld PVC caps and a 4" test plug or a cap, bushing, and a test plug. I'll be sure to update the thread once the machine is up and running. Thanks for all the help! This might be the best idea for an easy-to-build inexpensive 6 inch pipe barrel ever gt3073b. Brilliant idea. The 8 inch plug is $22 and 8 inch sch PVC pipe is quite a bit thicker than 6". 8 inch pipe holds a bunch of rocks. 26 inches long would be 5 gallons inside the plugs... I have found large threaded fittings to get really tight when used on a tumbler barrel. Not sure why. For sure if grit gets rammed in the threads but the threads are not exposed to the slurry in this case. This may be an issue. manofglass's compression type design might be a better choice to avoid the monster threads. 8 and 10 inch sch 40 PVC may have to be rotated a bit fast to avoid slippage(not climbing the pipe). 6 inch can have the same problem depending on abrasive. More slippage likely with finer abrasives. Which can force spinning the barrel a bit fast during polish operations when it is best to have slower rotation speeds. life is never simple.
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gt3073b
off to a rocking start
Member since September 2020
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Post by gt3073b on Oct 3, 2020 17:11:41 GMT -5
Link to my google photos albumIt's alive! I've temporarily loaded (possibly overloaded) the drum with some stuff I started on a an old (now dead) vibratory tumbler for metal parts along with some stuff we collected at Lake Michigan yesterday. I'm still waiting on grit and ceramic media from therockshed, so I used the dried rock slurry (no metal) from the old machine that still had a fair bit of coarse SiC in it. This is more of a leak test, so I'm not too worried about either not making progress on the rocks or damaging them. If they improve, that is a bonus. I'll run it as is until the grit arrives.
The drum is a 12" piece of 6" schedule 40 with the T-Cone plugs mentioned above, so the internal volume is at least 255 cubic inches. How much grit should I use for this volume? The drum runs at 53 RPMs. I think that is about right, but I have smaller drive pulleys if I need to slow it down. I'm open to suggestions. Thank you all for the help both here and in private messages. I really appreciate it!
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panamark
fully equipped rock polisher
Member since September 2012
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Post by panamark on Oct 4, 2020 12:41:02 GMT -5
8 and 10 inch sch 40 PVC may have to be rotated a bit fast to avoid slippage(not climbing the pipe). 6 inch can have the same problem depending on abrasive. More slippage likely with finer abrasives. Which can force spinning the barrel a bit fast during polish operations when it is best to have slower rotation speeds. life is never simple. [/quote] I have pondered this slippage problem quite a bit . Caulking/Gluing some kind of ridges inside seems problematical in terms of them wearing out quickly. I was wondering if the Piston sleeve idea would work here. Cut large windows out of the sleeve before gluing it in and it would interrupt the sliding. ? ? ?
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jamesp
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Post by jamesp on Oct 5, 2020 7:20:42 GMT -5
8 and 10 inch sch 40 PVC may have to be rotated a bit fast to avoid slippage(not climbing the pipe). 6 inch can have the same problem depending on abrasive. More slippage likely with finer abrasives. Which can force spinning the barrel a bit fast during polish operations when it is best to have slower rotation speeds. life is never simple. I have pondered this slippage problem quite a bit . Caulking/Gluing some kind of ridges inside seems problematical in terms of them wearing out quickly. I was wondering if the Piston sleeve idea would work here. Cut large windows out of the sleeve before gluing it in and it would interrupt the sliding. ? ? ?[/quote] Yes Mark, been there and and the sleeves can be modified as kickers. alternate: 8 inch is big enough in diameter to stick an 4.5" angle grinder in and grind ~1/8 inch grooves in it. And 8 inch sch 40/10 inch sch 40 pipe is quite a bit thicker than 6 inch sch 40 PVC pipe so wear is less a problem. Rarer for slippage to happen with step 1 grit due to friction, 500-1000-polish becomes a real problem because these are well done slower in speed. I found a stick of blue 8 inch PVC in a trash pile. It must be used for municipal water supplies. It is twice as thick as sch 40, about 8 feet long and was real heavy. I will try to find the schedule designation.
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