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Nice! thank you @professorbromide. If it seals everything up it should be gtg.

I'm geeking out on the chemistry of cement, mortar, grout, and concrete over lunch today. Check this page out: https://www.concreteconstruction.net/how-to/grout-or-mortar_o

I found at least two references that claim mortar has little or no lime in it.

This stuff looks like the perfect solution for you. It is $125 for a 50 lb bag. Kind of expensive, but it comes in a lot of pretty colors!

Or this stuff on Ebay. 3 lbs for $30

Nice research! I might grab that stuff from ebay. I would like to use this vortex filter in some application I may be able to seal the entire vortex section with this stuff. Thank you brother!