[PSUBS-MAILIST] Clearances

[Rick Patton via Personal_Submersibles]

Sent from my iPhone
I got a real surprise yesterday, I went to fit my large viewport in front on my K-350 and it wouldn’t slide inside the receiver that I had machined for it. They made it about 1/4” too small!
I should have double checked it before welding it into the front head but didn’t. 
I had the viewports cut in California and is to speck, 15”.  Kitteredge called out using gasket but a lot of you I believe used Silaflex that comes out of a tube.
I found someone who can chuck up something that is 16” in diameter so will have him turn it down 1/4” or so, so it will fit in the receptacle but I need enough of a gap on the edges for the Sikaflex to ooze out. 
Your thoughts? 
Rick