After securing plenum boards to the cross arms surface it flat and smooth. Cut the plenum channels and the vacuum holes. I leave a 1.25" ridge between zones.

Sand everything smooth. Important to get everything smooth to reduce/eliminate obstructions to air flow in the plenum.

Seal with 4 coats of shellac (spray can works great if you don't have a Cricket sprayer).

Attach your vacuum system. Test run to make sure it all works.

I cut my Trupan to be the same size as my zones and then edge band each piece with plastic laminate. Provides a good edge sealer.

Between plenum and spoil boards I use silicon chalk. A thin bead along the edges and a few in the middle to keep the spoil board flat. Engage the vacuum motors and let it sit for about an hour. Spoil board now securely held to the plenum.

Surface spoil board and your in business.

Start to finish about 1.5 days. Most is to let the shellac and chalk dry thoroughly.