Reply by Vrtigo1

I used some of the plastic blast gates that came with my HF DC and I can tell you that they’re junk. After a while they get sawdust built up in them so they don’t close all the way, and even before that they leak. I just recently made a few homemade blast gates out of 1/2” plywood with a 1/4” plywood insert that opens or closes the gate. They work really well and they’re dirt cheap.

Also, your comment about ducting on the three walls that don’t have doors…in my garage I chose to go across the front of the garage (where the door is). I just went right over the top of the garage door with 4” PVC, no problems at all. Just wanted to throw that out there in case you were thinking the door would interfere somehow.