glue between plenum and MDF spoil board

[JDGJr]

I need to completely remove the old spoil board, as assembled by the previous owner (so I don't know the details on how he did it). I have the MDF removed and the old glue removed from the plenum...

What glue is recommended for attaching an MDF spoil board to the sealed MDF plenum?

thanks!
John

[myxpykalix]

I used regular titebond II. When i did it i just used a roller and rolled it on using a short nap roller so you would only get glue on the "peaks" and not in the "valleys" so as not to clog up your plenum.

[dlcw]

I need to completely remove the old spoil board, as assembled by the previous owner (so I don't know the details on how he did it). I have the MDF removed and the old glue removed from the plenum...

What glue is recommended for attaching an MDF spoil board to the sealed MDF plenum?

thanks!
John

I use white caulk around the edges and at a few of the level spots in the field of the plenum. When I get down to about 1/8" I will add a new piece of 3/4" Trupan and caulk it in the same places as the original. I also band the edges of each zone with plastic heat activated adhesive edgebanding. My table (5x8) has 7 zones and each zone has its own Trupan spoil board attached to it. The edgebanding isolates all the zones from each other reducing vacuum leaks.

[JDGJr]

Thanks guys. I went with the caulk because it'll be easier if I ever have to get it all back off.

Don - do you seal the outer edges of the spoil board as well?

[dlcw]

Each one of my zones has a separate piece of Trupan. Each one has edge banding all the way around it. Then the Trupan is caulked into its spot on the plenum.

This virtually eliminates vacuum bleeding from one zone to another. Each of my zones and combinations of zones are specifically sized for certain material that I commonly use: 4x8, 5x5 and a 4x4 MDO board with t-slot tracks for holding down smaller work pieces like for signs and plaques.

I spent a while figuring out what zone sizes I need and then built the Gary Campbell vacuum box and plumbed my plenum so that each zone is controlled with a knife valve (like those used in RV dump systems).

Not often do I need to switch on all motors in my plenum. It operates about 95% on just 2 motors.

At an altitude of 2500' I pull about 7.5" of vacuum. Pretty good I think.