Hey friends, so our inner mad scientists got the better of us, and we decided to design our own vac pot and have it fabricated by a local lab glass shop.  The purpose for the redesign was to make something that could brew 2000 ml small batches of coffee. This way we could have reasonably priced siphon coffee, serve it quick style, and give our customers a bit of a show.  Because of its bigger size, we added a small spout at the hemisphere , and the 3 finger clamp that holds it can rotate forward, so the pot stays on its stand.  Here, check it out:

siphon test

For the test I just used a piece of rubber I found at a hardware store-as you can see it doesn't hold the gas pressure because it doesn't make a tight enough seal, so the water won't stay in the top chamber. Also it made a pretty bad burnt rubber smell and I doubt the rubber's food-safe.  SO it looks like I have to hope an existing siphon gasket will fit.  The people at sweet maria's let us look at their yama 8 cup gasket, and it looks like it should work-but they don't sell the piece by itself.

On to my question: does anyone know where to order rubber gaskets like this?  I thought Northwestern Glass would, but couldn't find them on the site.  I suppose we could just buy the top piece if we had to, but I'd also like to have a few gasket options.  The bottom opening seems to be slightly wider than the yama retail models, so the wider gasket the better.  The tube seems to be about the same as retail.

thanks!