I need to fasten the two halves of this vintage 1930s/1940s Detroit Products #123 signal arm together. They came to me separated, w/o the original fasteners, in a rusty condition. From an original photo, it appears that the fasteners used were a smooth, round head rivet on both sides (“double-cap” rivet)? The hole diameter is 3/16”. The thickness of the two halves together is approximately 3/16”.
In addition, the name badge appears to have been fastened with the same type of smooth, round head rivet. The hole diameter is also 3/16”. The thickness of those two halves together is approximately ½”.
I have been able to connect with the guy who broke down the main signal arm that I am now reconditioning. He did this about 10 years ago. He said if his memory is correct, he referred to the rivets as "blind rivets" with the nice side in the front. He does remember having to drill them out from the backside. The front head of the rivet was NOT painted. So if all this holds true for this signal arm I am reconditioning, can you set me straight on what rivets I should be using to replicate the look? It sounds to me like it was a standard pop rivet, placed with a common pop rivet gun.
Can someone help me identify what was used originally in this particular application, as well as source the replacement fasteners and the setting tools required?
The reconditioning phase of this project is now complete. This morning the local airport aviation mechanic used solid head aluminum alloy rivets on the arm. The name badge is fastened with aluminum binding posts. The entire assembly is all there, either original or new/improved. I will install this coming April/May and provide an update at that time. Thank you to all who provided guidance on this project--it is greatly appreciated!
This signal arm restoration project is now complete. It is time to get “my old buddy” back on the road to enjoy the pleasures of driving this 1948 time machine. Enjoy the new driving season everyone!
