Deleted
Deleted Member
Member since January 1970
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Post by Deleted on May 8, 2013 15:20:46 GMT -5
I am working on this little project. I am building a sphere from sheets of stained glass. I glued little squares of glass into lessor cubes. I am now at the stage where I must even out the edges of the lessor cubes so I can glue them together to make the two halves of the greater cube. I don't have a flat lapp and don't want to waste precious class time using their machine, so I made the poor man's flat lap. PARTS LIST: Plastic tub - new cost - $5 small granite slab - my cost FREE, call it $15 to you from a local granite ship like ours. Wet Dry Sandpaper 100-220-400 - $1 a sheet - $3 add $3 for 800-1500-3000 Water - cost? lol FREE! METHOD: Put tub on table Put granite slab in tub shiny side up Add water until it covers the slab slightly Put wet/dry sandpaper on slab - it will stick thru suction once saturated Sand away Total Cost - $8-$26 No the granite slab is not PERFECTLY flat. If one were to measure I will bet it is flat within 0.01" or better. I saw various tests done my machinists and they found 0.002" variance over one foot. Is that not good enough for slabs and the back of cabs?
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robsrockshop
has rocks in the head
Member since August 2012
Posts: 715
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Post by robsrockshop on May 8, 2013 20:36:04 GMT -5
Holy cow........got some extra time on your hands? LOL. Considering I have built simple machine parts using a piece of granite as a surface plate I think it's safe to say it's flat enough for a rock lol. Of course I was using it in a different way with die and scrappers to mark low and high spots. My biggest concern wouldn't be that the granite isn't flat enough but your ability to apply even pressure and avoid rounded edges etc or lopsides. Honestly I don't think id worry too much, test fit if it fits ok then glue them together and go with it your too far along to turn back now. I like the colors if you get the sphere cut without it flying apart post pics.
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Deleted
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Member since January 1970
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Post by Deleted on May 8, 2013 21:13:50 GMT -5
Thanks Rob. I used a water white epoxy meant for a spray coat. I wanted the thinnest possible epoxy section between the glass layers. I dropped one on concrete, luckily it landed on some epoxy that had oozed out. No wear, no breakage, no worries!
It looks like I can get a side done in 30 minutes. 16 sides 8 hours. I'll do a couple a day while I wait for the phone to ring at work. I am going to stop at 400 grit so the frosted area will grip better.
If I ever did this again, I'd go with bigger lessor cubes and trib them on the saw before gluing.
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Post by Pat on May 9, 2013 9:10:45 GMT -5
Hope you show the finished product! Reminds me of fordite.
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Deleted
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Member since January 1970
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Post by Deleted on May 9, 2013 13:15:31 GMT -5
Pat, I'd love to see a 4" sphere of fordite!
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Post by paulshiroma on May 9, 2013 21:30:02 GMT -5
Scott, love the ingenuity. Thanks for sharing the info and setup! I'll have to give this a try.
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Deleted
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Member since January 1970
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Post by Deleted on Jun 19, 2013 6:32:37 GMT -5
A friend in China taught me to grip the piece as close to the sand paper as possible and work in tiny circles. It really worked for me on softer stone like alabaster and Chinese soapstone (a little harder than our alabaster). Seems like it would work on anything harder too. I really had a problem with the piece rounding like the face of a cab until I tried his method. Jim
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billg22
spending too much on rocks
Member since November 2011
Posts: 451
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Post by billg22 on Jun 19, 2013 11:16:41 GMT -5
Scott, thanks for reposting this. I was thinking about trying to window some rock and this gives me a few ideas. OK, say that I've just cut a small rock on a tile saw. How long would a one inch by two inch stone window take to polish? I think I have most of the "parts". I guess a floor tile from Home Depot would work.
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Deleted
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Post by Deleted on Jun 19, 2013 11:50:50 GMT -5
a small window by hand? maybe half an hour. The longest, of course, is to rough the window. Then juts go thru the steps until shiny!
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Deleted
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Member since January 1970
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Post by Deleted on Jun 19, 2013 11:52:24 GMT -5
Hope you show the finished product! Reminds me of fordite. I will, but I have decided this method is too slow for this project. I plan to saw cut the edges clean, then re-glue... I promise Pat.
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