Construction:
    
Cut the  pine boards to the lengths listed in the cutting list.
    
Next you will have to join the previously cut boards together so you have two side pieces, a top piece and a bottom piece. First drill a few 5/16"-3/4" deep holes in the edges of the two pieces to be joined.  Measure, mark, and drill these hole carefully so the boards and dowel pins will line up properly.  Once the holes are drilled, apply glue to the dowel pins and the edges of the boards to be joined, insert the dowel pins in the  holes, join the two boards together, and clamp together till the glue sets. I used two dowel pins in each of the side pieces and three in the top and back pieces. When you finish, you should have 2 side pieces approx. 18"x18 ½" (the two side pieces), one piece  approx. 18½"x24" (the top piece), and one piece approx. 18 ½"x 22 ½" (the back piece).
    
Next, align one side piece at a 90-deg. angle to the back piece and  drill two 5/16" holes all the way through the side of the side piece into the end of the back piece. Drill these holes approx. 1 ½" deep with one hole approx. 2" from the top and one hole  approx. 2" from the bottom. Repeat this on the other end of the back piece with the other side piece. Once the holes are drilled, glue dowels into the holes in the end of the back piece. DO NOT PUT ANY GLUE IN THE HOLES ON THE SIDEPIECES. Set this aside to dry for a few hours.
    

Next slide the holes for the two side pieces over the pins in the back piece. If the fit is too  snug, you can enlarge the hole slightly for a little better fit. Once the three sides are together, set the top piece on and align it with the side pieces. Next drill several  5/16"x 1 ½" deep holes trough the sides of the top into the edges of the three sides. I drilled two on each side and three in the back of  the top. Glue dowels into the holes on the top edges of the sides. DO NOT PUT  ANY GLUE IN THE HOLES DRILLED IN THE TOP. Set this aside to dry for a few hours. When finished, you will have four pieces that look like the ones shown to the left:

Here you can see the placement of  the holes and the dowel pins on the  various pieces.

Next mount the exhaust fan in one of the sides and attach the power cord as shown to the left:

The fan I bought had plenty of space behind the grill to put in a piece of electrostatic filter material. Attach the flex duct and run it out the window. If you prefer, you could get a combination light and exhaust fan and mount it in the top.

For lighting I simply cut a hole in the top of mine so I could shine my magnifying light down through the top.    





 

     
The pegs and holes allow you to quickly assemble it, or break the whole thing down and stack it for storage as shown left

     Have fun!
     Kirk Schermerhorn