Editor's note: This is the second in a series on Hand Planes by contributor Ralph Bagnall. If you missed the first, on Block Planes, you can catch up here.
After the Block Plane, the Jack Plane should be your next pick. Hand planes are designated by number, the higher the number, the longer the sole of the plane. Jack planes are typically #4 or #5, and are excellent general use planes. The Jack plane can perform most planing chores. It is commonly used for shaving doors that stick, leveling high spots on glued-up panels and a host of other tasks.
One of the best uses for these mid-sized hand planes is jointing edges for gluing. Set a light cut, and let the long base of the plane ride over the edge, taking down the high spots. Now, the astute reader will wonder how to ensure that the edge being planed is perfectly square to the face. The answer is... you don't!
Since it is virtually impossible to ensure a dead-square edge with a hand plane, don't try. The secret to a good glue joint is to joint the mating edges at the same time. Lay out your boards, then "fold" them as if they are hinged with the glue edge up and clamp them together in your vice. Use the plane to pare down both edges until you get a full shaving all along both board edges. By doing both in this manner, any angle you happen to plane in will be matched by the second board, canceling any variation. To demonstrate, I purposefully planed these edges with a noticeable angle. As you can see, the angles cancel, resulting in a flat panel.
Rockler offers a variety of Jack Planes, including the affordable Groz (below left), the mid-range Stanley Bailey (below center), and the higher-end Stanley Sweetheart (below right). A good quality jack plane will be an invaluable addition to your tool kit, both around the shop and home. A few swipes across the top of that sticking door, and it will swing free again.