Sealing Spoil Board

[Ron Hampe]

LDF & MDF finally came in and I have a lot of Kilz paint which is an excellent sealer for odors. Will it work and if so will 2 coats of it be sufficient or should I using a different product?
Also have an exterior grade polyurethane. Thanks

[gtgmarine]

Are you talking about sealing the edge of the spoil board so you don't lose vacuum?
If so, I just roll on a nice thick coat of wood glue like Titebond II with a small 1" wide roller.
You could do the same thing with the polyurethane.

[Ron Hampe]

I need to seal the bottom of the grid board (119" x 49") as well as the edges. I've never worked with mdf before and from what I'm reading I need to spray 2 coats of primer then 2 coats of polyurethane to get the best seal. Is that true? I have a BlackBox Hurricane vacuum and assume I want the best seal possible for it to work well on this table.

[gtgmarine]

Nope. You don't want anything on the mdf surface - only on the edge.
You need to usually take off .01-.02" on each side to remove the surface sealer. You want maximum airflow through the mdf.
Some folks use silicone or a little double stick tape near the edges and a little in the center to keep the mdf in place when the vacuum is not running.

[Ron Hampe]

I was referring to the mdf with the grid cut into it. What is the point in sealing the edges if the bottom surface below the grid isn't sealed as well?

[gtgmarine]

Ok, so you are talking about the vacuum plenum. Mine is phenolic but sure, you should paint or seal the plenum after making it flat. Sorry for the misunderstanding.

[Ron Hampe]

Thanks. These are new boards. I bought my Stinger used and it came with t-tracks and was not setup for vacuum.