Lapping plate CD

Tom Curran

Elite Cafe Member
Joined
Feb 18, 2007
Messages
451
Location
upstate New York
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
 

Takoyaki

Member
Joined
Dec 29, 2015
Messages
75
Location
Japan
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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