Making Glass Topped Buttons

[alex_holden]

59 minutes ago, SteveS said:

Wow, Alex, those buttons are beautiful.

 

How did you cut the glass rod?

How did you polish the ends of the buttons?

 

Thanks Steve. Cutting the glass rod without chipping it was the trickiest part; I experimented with lots of methods. The final method involves turning it in the lathe and using a knife-shaped carbide tool to score all the way around, then taking it out, wetting the scratch, and snapping it in two with both hands. There is a particular knack to the way you snap it, it takes quite a bit of force and the fact that the piece you're breaking off is very short makes it more difficult (any attempt to hold the short end in pliers, vice, etc. resulted in large chips).

 

Grinding and polishing is fairly easy but time-consuming. I clamped the piece in a block of wood that held it perpendicular, then lapped it on a 400 grit diamond plate in a tray of water. I had to take off maybe 1mm from each end to eliminate any small chips, repeatedly checking it with callipers to ensure I stop at the correct length. Next I gripped it in a drill chuck attached to a motor and used a wet 400 grit diamond paddle to round over the top end. The bottom end I left at 400 grit but I used 2500 grit wet and dry paper to polish the scratches off the top end (surprisingly it worked fine to skip over all the intermediate grits). Finally I buffed it using a hard felt mop charged with cerium oxide paste.

[Isel]

On 4/4/2020 at 3:22 PM, Don Taylor said:

Hmmm.  Trying to work out what the hole configuration means, especially the large egg-shaped hole.

 

Slanted rest with a thumb strap and a ?

Don, if you had some interest about the tale involved, please send me a PM?