Limestone Seahorse

[Rcnewcomb]

although I am a bit hesitant to mess up my machine with the dust

Hold a shopvac nozzle near the bit while it is cutting.

[scottp55]

G.,
I cut a fair amount of stone/gem with sintered diamond bits on a Foredom, BUT ALWAYS wet!
NONE of my Diamond tools like dry!!! Fractures the diamond and rapidly deforms the matrix of the sintered shape.
On my Diamond Pacific "Pixie". NOTHING ruins a 4" wheel faster than not enough water!
Stay Carbide.
2 cents.
scott

[Tailmaker]

Thanks Scott, maybe I should not ruin the diamond bits with dry stone then....the stone experiment would anyway just be an escapist distraction from my official first priority to reorganize my shop.

[scottp55]

May have spoken too quickly Tailmaker
JUST masked/goggled up, and took my least used full sintered shape which was a solid sintered diamond truncated cone.
Grabbed a damaged selenite crystal specimen(Mohs 2), and a non-nacreous shard of oyster shell(approx. Mohs 3), and ran Foredom at max 18K and tried to approximate 1 IPM.
Spent about 5 minutes using just the shank side corner, and after rinsing with water, under my 10X loupe, I couldn't see deformation of the corner or break down of the diamond.
Sooo.....may be worth an experiment? (at YOUR cost:)

For me, I LIKE Randall's results with using old carbide bits

DO know that I drilled 200 holes in oyster shells for my Mom last Christmas for ornaments,and would up with Drillman1's .0625" downcut carbide in the Foredom at about 16K after trying several different bits, and drilled wet by method of putting a sponge in rubbermaid container and pressing shell down until barely covered to avoid dust.

Zip,Zero,Zed experience with new diamond coated router bits
Sorry for speaking so fast:(
(experimenting saved me from cleaning garage:)
scott