Lapping plate CD

Tom Curran

Elite Cafe Member
Joined
Feb 18, 2007
Messages
451
Location
upstate New York
Thread starter #1
I don't know where this idea came from, but here goes:

I was wishing to hone my gravers, cutting silver, and a polished heel and face make such a difference.

However, I don't have a ceramic lapping plate. Have been reading about folks using acrylic plates, masonite plates,etc. I haven't gotten around to making one yet.

Today I am sitting at my computer toying with an old CD. A certain 'dawning' effect was slowly taking place.....suppose I put the CD on my GRS platter....right on top of the 1200 grit wheel. It fit, and runs pretty true.

So I fogged the surface with some 1000 grit paper, making the scratches go from center to edge. Then I spread some 1800 grit diamond lapping paste on there, and HOKEY SMOKES! I can lap the face and heel to a mirror shine, using my double angle fixture! No more rounding the edges over, stropping by hand!

Tom
 
Joined
Dec 29, 2015
Messages
69
Location
Japan
#3
Hi,

don't use sandpaper for matting the disc, as particles of the coarser grit will stay on it!
Gemstone cutters use a clean scribe or an old clean kitchen knife to scratch radial lines (groves) into the polishing disc. Mix the polishing powder with oil will keep it longer on the disc. I use oil, thinner or thicker ones. Works well!
The polish gets even better if You use a copper or brass plate/sheet instead of the acrylic !
In gem polishing, acrylic Disk are used to polish softer stones, lead/tin wheels for Quarz, garnets, beryl, (mohs hardness 6-7)
Copper/brass is polishing harder stones well, like corundum, spinel, chrysoberyl (mohs hardness 8-9)
Cast iron laps are used for diamond cutting/polishing. (Hardness 10)
 

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