Dr_Zinj
Veteran Member
Wooden blocks are fine as jack stands. The Portsmouth "Kittery" Naval Shipyard uses wood block cribbing to hold their subs up in the drydock to work on, so wood IS reliable. However, they do need to be large enough, positioned properly (not so the weight is going down the grain like you were going to split it), and be the proper kind of wood. Small, soft, pine blocks don't cut it very well; whereas a heavy, dense elm is nearly indestructible.