Finally got my version of thien separator working after several rounds of trial and error. Thought I could share my findings. It’s made of a 5 gal big-box bucket, plywood, and plastic plumbing fittings. A 32 gal plastic trash can was used for collecting dust. Silicone adhesive and insulating self-adhesive tape were used to make the separator and dust bin combo as air-leak-free as possible.
This is inside the separator looking at the intake pipe (black) and the pipe (white) connected to the shop vac.
What I found:
1. The separator and the bin should not leak much vacuum, otherwise the separator doesn’t do its job. Without tight seal, a lot of chips and dust accumulates inside the separator (blue) and whatever doesn’t goes to the shop vac. The self-adhesive insulating tape is a great help here.
2. I’ve initially made a mistake collecting dust with a 1-1/2” hose attached to the separator intake, while connecting the separator to the shop vac with a 2-1/2” hose. Because of this I ended up with collapsed Brute can, multiple air leaks, and almost all the dust going directly to the vac.
A new plywood ring, seen on the first photo, installed inside the can helped to keep the system leak free, but the 32 gal can still collapsed to the size of a 5 gal bucket…
When I replaced the 1-1/2” intake hose with a 2-1/2” hose, things started working properly. The plastic trash can no longer collapses, just warps a bit; a harder plastic barrel would work better. The shop vac is clean:
My build, the plastic bin, the insulation turned out to be fine. After cleaning up the garage, I will start removing the old blown-in insulation from the attic area—this is when the 32 gal bin will come handy. All the info on how to build the separator can be found here:
-- "If you're not counting the ripples when throwing pebbles in the water, you're wasting your time."