No-Mask, No-Glue Plenum

[joelschuman]

Finally found a week to make a new plenum.

Added 3/4" BahamaPly to original baseboard by rolling out a gallon of white glue and weighting,
Added 1" MDF same way.
Cut 4 zones by overlaying 5' x 5' and 4' x 8'.
Set threaded inserts in plenum. Screwed spoilboard to plenum with fiberglass screws.
Now can cut 5'x5' or 4'x8' without masking panels.
Now spoilboard goes on and off quickly without mess or dry time and no glue failure to cause leaky edges.


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[paco]

Clever, nicely done and clean. Good work Joel!

[Brady Watson]

Looks great, Joel! It's a shame you have to cover it up!


-B

[kodiak]

What did you use to seal the plenum/spoil board? Nice clean job with that... I think my new set up will be very similar, thanks for posting that.

[joelschuman]

Thanks, Paco. Brady, it is a shame! There's something very pleasing about it, and I'm thinking of doing some cabinet doors with a smaller version...
Big J, For the plenum, I sprayed 4 heavy coats of Target's Oxford HybriVar Alkyd Varnish (water based), DA-sanding 220 after 3rd coat. I used a HVLP cup gun, so there was almost no overspray - didn't even mask the cross members - just moved the x-car back and forth. After drying, I waxed with paste wax - the WB varnish stays tacky for a long time, and I didn't want any surprised when it's time to change spoilboard. The MDF spoilboard is unfinished but I removed the "skin" on the bottom. I don't resurface the top until it's chewed - it draws just fine.
BTW, I considered the clever ways of indexing posted here, but I stuck with my simple way of rabetting the spoilboard along the X and Y axis. Nothing to lose, no problem with crud collecting in the corner of an alignment strip, no moving parts. If I need it exact, I use the base block of my 4" engineer square against the workpiece and the rabett.