Assembly should be carried out systematically using exactly the same method every time the bassoon is assembled or disassembled.
For Fox bassoons
Wing joint held in the right hand should be inserted into the small bore of the boot joint (held in the left hand). The engraved line at the bottom of the wing joint must be aligned exactly with the corresponding line on the boot joint to ensure perfect closure of the crook keypad by the low E key.
For all other brands (e.g. Schreiber)
The wing joint should be locked together with the long joint and both joints inserted simultaneously with the boot joint cup resting on the floor. When assembled the low E key should be depressed to check that the crook keypad is perfectly closed on the crook nipple as imperfect closure is the major cause of difficulty in obtaining the lowest notes easily.
When inserting the crook into the wing joint, downward pressure must not be applied to the tip end of the crook. The crook should be held in the right hand with the finger tips resting on the top of the crook, little finger approximately 3 cm above the crook nipple and the bottom of the crook supported on the hand between the thumb and first finger where upward pressure should be applied to counterbalance the downward pressure as the crook is inserted into the wing joint ferrule with a twisting motion.
A very small amount of cork grease should be used before insertion (especially if the crook is new) to make insertion easier. Bent or split crooks are very expensive to replace and difficult or impossible to repair effectively. The above method of insertion will prevent these problems occurring.