You know John I now recall that the pins which Hermann Strecker used in his collection were mostly brass.
I remember well seeing many of them with these little "curly-q" green filaments shearing off of the pins.
I'm certain that may have been in part to the humidity present in the rooms of his Reading Pennsylvania home.
He passed away in 1901 at the age of 65 so his accumulated collection was largely ammassed between the 1850s and 1900.
To be sure, the heat and humidity of summertime must have been awful during those times as there was no such thing as air conditioning.
To be fair, many of the entomologists probably used the best pins available to them. But by our standards, they were not that great. I too have seen brass pins - and they bent really easily when pined into cork. Most of the old pins I've seen look like unpainted steel, but the wire is likewise very flimsy and bends. And then, there are the pinned collections that are still in cork. Some of the pins are rusted at the tip inside the cork, and so you have to use pinning forceps to pry them out.
But once you move the bugs to foam pinning substrates - all is well with the world!
Post by thepinmaker on May 24, 2021 7:28:06 GMT -8
About brass pins,
Is impossible to get the strenght that you need with thin diameters on brass wire, with stainless steel or high carbon steel, wire you can get from 1300 N / mm2 to 2000 N /mm2, and in brass only you can get 1100 N /mm2, .is a big difference.
The brass pins without any plating coating, they don't have corrosion resistance, and with a nickel plated coating they have higher corrosion resistance than the black although far away from stainless steel 304 or 316, is totally normal that the brass pins inside the cork are totally affected by the corrosion, another parameters, that affect the corrosion, is the humidity, the temperature and the sweat fingers of the user, that some people in specific places close to the ocean and in summer time are wetty, i don't know if everybody works in gloves for your applications, , this is what is happening when they use pins in another applications.
About producing brass pins
The pin machines are happier to work with wires softs than hards, the tooling last longer and the machines don't need too many maintenance jobs,,producing brass pins is easier than working stainless steel or stailess steel spring wire
Post by thepinmaker on May 27, 2021 1:48:29 GMT -8
My son nows lives in Belgium, and last week end visited the city of Leuven, that has maybe the biggest sculpture about specimen pinning, maybe everybody knows this sculpture, i wanted to share with you
NOTHING IN A QUAINT OLD town of Leuven really prepares you for a sight of a giant shiny green beetle impaled on a 75-feet high needle. ( 23 meters) The name of the sculpture is ‘totem’ and is a work by Belgian artist Jan Fabre, who also covered a ceiling of the Belgian Royal Palace in bugs. This very unusual sculpture decorates the square in front of the historic KU Leuven University Libraries. Its appearance becomes much less bizarre if you know the artist’s intention. The sculpture was erected in 2004 to commemorate the 575 years of the university KU Leuven. A library is a collection of knowledge, carefully handpicked, cataloged, and put away for safekeeping, somewhat like a bug in an insect collection. Furthermore, the anatomy of an insect is reminiscent of a clockwork, a tiny precise mechanism, a product of science and technology. Some say the totem represents the fragility and ephemeral nature of life.
Very cool sculpture, and I had never seen this before either. I made a comment in another thread about how easy buprestids are to pin - just "grab and stab" them. Had no idea one could go this big using that method!
Here in Pittsburgh, there is a similar sculpture on the campus of Carnegie Mellon University. However, it is a long silver pole mounted on an angle, with several people walking up it. At the base are several sculpture people watching. Every time I drive by that, my eye is tricked into seeing the sculpture "observers" as real.