1986 Tournament 27 projects

[FLexpat]

Originally Posted by Ed

Thanks, Martin. I knew something was off.

When the valve is mostly closed and the bag is not tight, I was showing 20 inches of mercury. (See attached pic).

When the valve is mostly open, and the pump sucks the bag tight, I was showing 8 inches of mercury (the original picture).

None of this makes sense to me. The more I open the valve and the tighter the bag is sucked tight, the mercury should go up, not vise-versa correct? It seems to be doing the exact opposite for me...

That would make sense if the gauge is between the valve and the vac pump. Sounds like the valve is set up inline as a flow control rather than in a tee as a vac control (as a bleed valve to atmosphere). You want a cheap vac gauge on or near the bag. I have a bleed valve (called a vacuum control valve) in a tee that allows me to set the vac to the bag and the pump; closed I get 20" and open I get 3-5".