fosldog
off to a rocking start
Member since November 2008
Posts: 13
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Post by fosldog on Mar 23, 2009 22:48:14 GMT -5
Ive started to use a raytec vibratory lap to polish up a few of the larger slabs ive cut and have a problem with the grit loading up and drying on top of the slabs after a few hours.
Ive tried wetter and drier grit slurries with the same results. Ive taken to using a putty knife to put the grit back in the pan where it belongs but this is a hassle and doesnt seem to be right.
The unit is level but does seem to run a bit rough so perhaps this is part of the problem. Any help and suggestions greatly appreciated.
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mossyrockhound
fully equipped rock polisher
Member since January 2011
Posts: 1,278
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Post by mossyrockhound on Mar 23, 2009 23:58:37 GMT -5
Well, at first I thought you were talking about keeping the grit in the lap, but I see you are getting the slurry on top of the slabs. I don't think you can prevent this from happening, but maybe one of the experts out there can help you out. Other than keeping things plenty wet so the slurry will flow with the water off the top of the slabs, there may not be a good solution. I've had the polishing compound splash all over the place but I haven't had a similar grit problem. You said you were scraping the grit off the slabs with a putty knife, indicating the grit is drying out. If you are losing your slurry/water, put a shower cap (or similar) over the unit to keep the water in where it's supposed to be.
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Post by Jack, lapidaryrough on Mar 24, 2009 12:23:52 GMT -5
Too much water and the grit won`t cut.
I run two 27" Vibe Laps, and the courses grit i use is 220 grit for the 1st and final lapping!,
And a IV - Drip over the center of the lap plate. Face sand all material the plates well last for ton`s of lapping.
And the slurry should be a light mud to move with the slab. To thick and dry the stone well dance over each other and the chips well run between the lap and the stone leaving cork screw Pig tail`s across the surface of the material.
Oh the dry cement from a thick slurry on the stone `s, well Acid well clean it off.( Don`t let the stones dry out )
I found this out the hard way, I put Coconuts in a acid bath cold. and the next day i seen a few were calcite`s center, melted away.
Though it did clean the dry grit off the surface of the geodes. "And finish the with glued grit pads. or belts.
Loose grit finish well look frosted, if you go through the final polish.
always finish sand with 600 grit glued sand pads, After running the 220 grit on the laps it break`s down to 400 fine real fast. Always run a recharge for at least 8 hours to go the drum sand or disk. ( Bull Wheel )
pencil Mark the material to see how flat your material is doing on the lap, and as always`s best to fill a lap full and remove a stone tell they all move slowly in a circle.
Jack
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Mudshark
fully equipped rock polisher
Diplomacy is the art of saying 'Nice doggie' until you can find a rock. Will Rogers
Member since December 2008
Posts: 1,083
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Post by Mudshark on Mar 24, 2009 16:14:58 GMT -5
The same thing happens when I use my 12 inch Covington.And I do the same thing you do with the putty knife.I always thought it was normal.It doesn't happen as much in next stages but I still get a little on the slabs.I just make sure I clean the slabs really well between stages and they usually come out nice and shiny at end.I've seen a few pics of other peoples vibe laps and all the slabs were covered with grit so that's where I got the idea that this was just part of the process. Mike
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