Vacuum “Catastrophe” Averted

by Tig Tillinghast

We turned on the vacuum over at the re-done bush in Strafford yesterday evening. It involved a lot of last-minute plumbing into the evening. When it went on: only about 8 or 9 bars of mercury. That’s a little less than half of the desired level of vacuum.

[Installing a saddle (interface between lateral line and main line). Hopefully not creating a vacuum leak.]

Robert concluded that it was the saddles we’d put up throughout the bush, as the couple he checked down by the shack seemed to be leaking. He was despondent. I was despondent. Two months of work to fix the old leaky system, and we had a new leaky system. It was dark, and we didn’t have time to investigate or even start to fix.

I didn’t sleep well. Woke up around dawn and went up there to check it out for myself. Found that the saddles were holding pretty well. Found 5 major leaks – mostly your typical sorts of things, such as end caps that were never put in place, or a saddle that wasn’t hooked into its hole.

Came back down after a couple hours of work, and the vacuum was up to 16 bars of mercury when all five mainlines were open to the vacuum. When I shut off one in particular, the others went up over 18 bars, so I know I have some work to do on that one line. Must be a leak or two I missed. We’re going to have good vacuum this year, and that’ll bring in another 50-80 percent of the sap we’d get with just gravity. I am very, very relieved to know that all that work and expense will actually pay off.

In an hour or two, I’ll turn on the smaller vacuum at our smaller bush here in Thetford Center. Will likely see the same thing: terrible vacuum, until we go up into the woods and find what sort of crazy thing has happened to the line over the last ten months. Will actually be fun. I’ll bring the dogs and make a nice walk of it. This afternoon we should see our first sap flow, although I doubt we’ll get to boil today. Gives us an extra evening to prepare and clean the sugarhouse.