The Dad_Ohs
fully equipped rock polisher
Take me to your Labradorite!!
Member since September 2012
Posts: 1,860
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Post by The Dad_Ohs on Sept 28, 2012 22:55:34 GMT -5
in among everything else I got was a box of grits .... they are size specific and I was wondering if it was better to use them than the mixes I have now....
they are: 60, 80, 120, 600, cerium polish
I am using; 45/70 (wanted to try a stiffer grind on agates and other harder stones when I ran out of 60/90, 120/220 500 AO 1000AO for softer stones AO polish
I plan on buying more 60/90 and keeping the 45/70 for really hard stuff like agates or rocks that I want to strip the outer, trash layer, off of.
Thanx in advance ... not just for here, but for everything... you people have been most excellent to me with your help & info... I want all to know I really do appreciate it!!!!
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Post by Toad on Sept 28, 2012 23:04:09 GMT -5
Generally, the mixes are cheaper alternatives for tumbling. But as I move rocks from one stage to the next I generally go to the straight grade grits. No problem with using mixed grades for the initial grinds. Saves you money for the other stuff.
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Post by catmandewe on Sept 29, 2012 0:32:15 GMT -5
The graded grits are generally used for flat lapping, the mixed grits work great for tumbling but can add scratches to items on the flat laps.
Tony
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Post by johnjsgems on Sept 29, 2012 7:33:29 GMT -5
Straight grades will break down same as mixed grades so no real performance difference in tumblers. If it is old stock and not well labeled it could also be mixed grades. Back in the dark ages mixed grades were called for instance "600 ungraded" and now 5F or 500F (500 and finer) etc. Some of my dad's cans of grit said "400" in large type and below 3F for instance. Many people back then didn't bother to differentiate especially if they were only tumbling. It is pretty common for people who flat lap to ask specifically for graded grit.
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The Dad_Ohs
fully equipped rock polisher
Take me to your Labradorite!!
Member since September 2012
Posts: 1,860
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Post by The Dad_Ohs on Sept 29, 2012 13:36:04 GMT -5
thanks all for the info.... It was probably what he was using on his slabs to polish them after sanding on the Richardson machine I got. (it has a nice selection of diff grit papers for it. Could they be used on a bull wheel?? I have one of those too and no idea what he used on it. Also anyone use this>>>>>> Diamond Spray - is a sensible alternative to aerosol types. The spray is available in a 2 Oz. Pumpbottles. The vehicle is designed to dissipate quickly leaving auniform concentration ofexposed diamond particles onthe work material. Simply applythe spray where the polish is required. It sounds like the Diamond Dust is mixed in with the spray and you spray the pad and as it evaporates, it leaves behind the diamond residue for lapping. does that sound right?? It is, i think, an alternative to using a Diamond paste for lapping cabs. Maybe? ... anyone???
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Post by johnjsgems on Oct 1, 2012 7:48:30 GMT -5
Many facetors like the diamond spray. It seems a little more expensive for lapidary to me. If by Bull Wheel you mean a large polish disc save it for polishing. Either an oxide polish or the diamond. If it is used what color is the residue? If kind of a peach color it likely is cerium. If white it could be tin oxide or aluminum.
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jimrocksg
off to a rocking start
Member since October 2012
Posts: 1
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Post by jimrocksg on Oct 1, 2012 11:53:47 GMT -5
Roughing agates,jaspers,pet wood and coral takes so long.For coarse grit i use 16 and 36 and 100 mixed in 6 inch dia. rotary at about 80 RPM.Barrell of 6 inch sch 40 pvc is 20 inches long holding 12-15 pounds of stone.After 3 days the grit is reduced 100% to mud and i recharge after washing mud away. The sales rep for Washington Mills works w/me on saving money.The 36 and larger grits are used in the sand blasting bussiness and are cheap.He also said to keep the temperature down to increase life of the S Carbide. Just a side note-80 RPM for coarse and 220 grit.25 RPM for 500 grit and polish for these home made sch 40 PVC barrells. 8 grit is on the way for experimentation.
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Post by johnjsgems on Oct 1, 2012 14:14:07 GMT -5
8 grit must look like ball bearings or double ought buck shot.
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quartz
Cave Dweller
breakin' rocks in the hot sun
Member since February 2010
Posts: 3,341
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Post by quartz on Oct 1, 2012 21:59:46 GMT -5
We have used 16 grit for several years, like it. Please do give us a rundown on the 8.
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The Dad_Ohs
fully equipped rock polisher
Take me to your Labradorite!!
Member since September 2012
Posts: 1,860
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Post by The Dad_Ohs on Oct 1, 2012 22:14:19 GMT -5
Many facetors like the diamond spray. It seems a little more expensive for lapidary to me. If by Bull Wheel you mean a large polish disc save it for polishing. Either an oxide polish or the diamond. If it is used what color is the residue? If kind of a peach color it likely is cerium. If white it could be tin oxide or aluminum. I found a package of cerium in among the grits so i would guess that's what he was using.
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The Dad_Ohs
fully equipped rock polisher
Take me to your Labradorite!!
Member since September 2012
Posts: 1,860
|
Post by The Dad_Ohs on Oct 1, 2012 22:20:50 GMT -5
Just a side note-80 RPM for coarse and 220 grit.25 RPM for 500 grit and polish for these home made sch 40 PVC barrells. 8 grit is on the way for experimentation. Do you use a stepped pulley to change the RPM's on the tumbler?? or do you have a rheostat (dimmer switch/dial speed adjustment) on the motor?? the sandblasting media you use, is there anything special about it or is it just plain sand blasting media?? Where does one find 16 & 36 grit?? is it ground down SC wheels? I have a large quantity of agates and it might come in handy for the initial grind!! 8 grit sounds like a beast... please do keep us up to date on how it goes.
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Post by johnjsgems on Oct 2, 2012 10:19:31 GMT -5
Look for "abrasives" on a Google search. You should find industrial abrasives sources. Lapidary dealers will generally carry the more standard grit choices. I think Kingsley North carries some of the coarser grits. The place I buy silicon carbide has good prices but no clue on lapidary uses. I have to converse with a nice lady in their Phoenix branch for lapidary related questions. Silicon carbide is a man made product and ground to any grit as required. Wheels are made from the grit not the other way around.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,155
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Post by jamesp on Oct 12, 2012 7:45:52 GMT -5
I have 2 tumblers.They each turn 2 barrels.One runs at 80RPM and the finisher at 25RM.Please think about sch 40 PVC pipe barrels.They are the toughest and easiest to open and close of any system i have ever used.6 inch pipe about 18 inches long w/end cap one side and 6-4 inch bell reducer on the other side with a Fernco 4 inch rubber cap.Access is 1(one) band clamp.Holds 15 pounds. The PVC pipe runs fine on solid steel shaft w/no rubber coating to wear out.So PVC to steel directly.These have run full time for 1.5 years,all 4 of them. The 8 grit and 16 grit are running as we speak(48 hours).I got free 5 pound samples of each from Washington Mills.The 36 grit is great.It is sand blast grit and cheap,comes in 50 pound bags at a sandblast supply.Larger grit reguires less water as it washes to the bottom due to it's weight(these rotary tumblers are slightly inclined so that they rest against the one side wheel on the east side of the machine and the coarse grit was accumulating on the low side of the barrel).Once the grit starts to breakdown and create the stickier 'mud' coating the rest of the grit will get picked up and spread in the rocks. Interesting that Washington Mills uses cheap electricty from Niagra Falls;it takes a lot of electricity to make silicon carbide.Washington Mills sells in 50 pound lots.Maybe 5 and 10,i am not sure.But i recharge the 80RPM coarse grit tumbler every 3 days.I only do agates and a little rose quartz.A 6 inch barrel with 15 pounds of rock turning 80RPM completly turns 36 grit into a fine mud-no grit particles whatsoever-that is the most aggressive speed i could use before i started to get surface chips on rose quartz(a sensitve rock).The PVC barrel is very loud.This speed is violent and fast acting.But still requires 4-8 charges of coarse grit and 12-20 days on coarse grit.80RPM for coarse and 220 grit.25RPM for 4-600 grit prepolish and polish cycles in the 6 inch PVC barrels.And the pre polish is 4-5 days and polish is 2-3 days,using 3 : 1 : 1 ratio of sugar-grit-plastic beads.3 cups : 1 cup : 1 cup for 15 pounds rock.Will figure out how to post and post photos on this site one day.(newbie).
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