A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Art Leung
Date: 2022 Jun 18, 11:20 -0700
Hi Eric - yes, it is curious why so many bubble fill ports were sealed with O-rings. On most of the Kollsman bubble chambers I have seen, there's not a lot of pressure on the sealing plate when the screws are snugged down. Some of them have a thicker sealing plate (and correspondingly longer screws) that seems to work better. I've attibuted this to either later manufacture (eg: with the electronic averager) or a depot level fix when the instruments came in for maintenance.
I'm surprised at the cost of the Viton. I found 6in x 6in sheets on Amazon (USA) for a modest cost: Amazon.com: VITON Rubber Sheet 1/8" Thick 6" X 6" : Industrial & Scientific