db wrote on Apr 2^nd, 2011 at 6:00am:

I wonder how changes in humidity would affect the wooden ones.

My guess is that the all wood model would suffer a bit from humidity, especially since the 1" dowel I used is pine (which is relatively porous).  I bought a 1" dowel in oak that I'll use for a "re-make" of an all wood unit.  Since it is more dense, I'm hoping that it would be a better combo for purposes of compression.  

In any event, if I take one of these to the field, it would most likely be the 6:00 unit.  It is a fraction shorter than the all wood (8:00) unit and only weighs 1.75 oz.  One thing that cannot be seen on the metal units is that the compression is so good that a string has been added around the base of the handle so that it can reach the top of the piston.  The string creates a slight air gap in the O-ring allowing you to fully compress the unit for travel.  Otherwise, it is a real battle to get the piston all the way to the bottom and have it stay there.  There was enough natural "air bleed" in the all wood units that the string was unnecessary.

(Note:  All of the commercial wood units I've seen have a metal sleeve insert to avoid the "air bleed" issue in the cylinder walls.)

dd