First off, you can make yours as basic or deluxe as you want. I went with deluxe.

Materials:

150qt Marine type cooler with 1-piece lid


Brick of floral foam (or beads but I've never used them)


Tupperware container with lid



Distilled Water & PG



Hygrometer


Spanish cedar inserts from cigar boxes
(like the one on the right)



plastic or Spanish cedar to make shelves


2 Stainless steel screws

drill




Bread Knife


Saw


hot glue gun and glue (make sure the glue has no odor)


Exacto or Sheetrock knife


Instructions:

-Rinse out the cooler with water and dry
-Wipe down inside with alcohol to remove anything left on the plastic
-Leave cooler open for 3-4 days so that the plastic can 'gas out' any vapors left from the factory. These 3 or 4 days will be a good time to source the Spanish cedar, as this can take a while.
-If you've got a friend at a local cigar shop get them to save up the Spanish cedar inserts to line the walls
-Remove the handle opposite the end of the drain so that it can stand on end with the drain facing skyward
-remove lid retention strap if present
-Line up the inserts how you want them in the cooler as some will need to be trimmed to fit.
-Use the hot glue gun to glue the inserts to the walls and lid of the cooler. This takes time and lots of inserts! You can get some Spanish cedar planking but he inserts work great on the uneven and curved surfaces because of their flexibility.
-Cut shelves to fit in the divider slots that most coolers this size have
-Drill a lot of holes in the Tupperware lid
-Drill 2 keyholes in the bottom of the Tupperware container for the size of the screws you'll be using
-Cut the floral foam to the Tupperware container
-Screw in the two SS screws where you want the humidification unit to be (I like the lid) and attach the Tupperware using the keyholes
-Calibrate and attach the hygrometer
-Let the glue cure over night
-Soak the foam in 50/50 solution of distilled and PG
-Put foam in Tupperware and put on lid with holes
-Let cooler sit for a few days to season the wood, once this is done, you're ready to go!

Enjoy your hard earned work!