May’s Program will be the “History of Electric Clocks” by Mike Demsey
Show and Tell: Bring your Favorite Electric Clock
The March meeting started out with a sad note of Jack Heisler passing away in February.
He will be greatly missed for all his shared knowledge and teaching. He also helped in many roles in our chapter. He will be greatly missed. Thanks also to a generous donation from the Don Brown family in remembrance of Jack.
I also would like to inform you that David Lee, a longtime member of our chapter was recently recognized as a fellow in the NAWCC for all the work he has done for our organization. David is currently serving in his 7th year as a national board member. David, thank you for all the work you do to help out chapter as well.
The March presentation was given by Craig White showing how lead weights are cast. It was discussed that a small addition of antimony (5%) to lead greatly improved the ability to make the casting without large shrinkage holes in the center. The alloy addition of antimony allows for approximately a 50°F window of solidification. Instead of solidifying at 621°F which pure lead does, a lead-antimony alloy starts to solidify at 552°F and does not completely go to the solid phase until 495°F. This approximately 50F° transition is often called the mushy phase. In the case of casting the lead weights this was the difference between a large center shrink hole or no shrink hole.
Next casting challenge for me is casting brass. I am sure there will be some more humorous lessons along the way in learning this process. Hopefully next year I will have a success story about casting brass. If so there will be a new PowerPoint presentation.
We had some great activity at the silent auction table where a number of items changed hands. Bring something to sell and/or be sure to check it out at next meeting.
Educational programs planned for 2018:
May: Mike Dempsey will give talk on the history of electric clocks
September: Mike Dempsey will give talk on electric clock repair
November: Craig White will discuss a James Ferguson inspired Astronomical Clock.
We will have a board meeting after the May general meeting, so I appreciate it if all
board members and officers would attend this meeting. .
Thank you,
Craig White
