totally depends on the gap between the top and bottom form,can be between 55- 75lbs... too much, starvation of glue, too little,,devoids between the wood layers,=no outgassing of air bubbles== lamination failure,,5 to 10 lb air increments every 2-5minutes assures proper outgassing and better bond,, plus dont stand in front of either end of hose while inflating, too much air or loose hose fitting could and would mean personal injury,, ask me how I know ,,,good luck..( p.s.) its much easier to use the rope and wedge technique, plus your not limited to only one degree of reflex or deflex in your designs....j.p.
