If you’ve NEVER hung, or had to re-hang a door – especially one that sags and drags – the process, at first, might seem to be mystifying and a bit scary.  It’s not; and you can do a quite admirable job – using a continuous hinge and a few common tools you probably already have! 

As a matter of public record,  Austin Baer earned a patent for his design of hinge leaves with intermeshed gears in 1963 and formed the Roton Company to manufacture the product. He earned a second patent, in 1968, for adding thrust bearings to his original design. As the patent expired in 1985, Hager Companies purchased the company in 1989.  You can see the current offering by going to http://www.hagerhinge.com/ and scrolling ‘products’ for ‘Roton Continuous Geared Hinges.'

"The continuous hinge, with intermeshed gears and thrust bearings, allows the weight of the door to be distributed over the entire door length rather than concentrated on two or three spots as is the case with pivot or standard hinges. This provides an excellent solution to heavy traffic or abused door openings in new or existing construction," stated the original patent documentation.

Baer’s hinges were furnished with special screw fasteners that had an ‘undercut’ to the screw head, causing full contact between the screw and the hinge location and assuring a tight, reliable installation.

Today there are several manufacturers of continuous geared hinges, but not all manufacturing processes are the same – and the resulting products evidence this fact. 

Usually, a door will need to be re-hung, in the existing frame – steel, aluminum or wood – because a condition exists that causes the door to rub against the frame and/or drag at the bottom and can become hard to open and close. Such a condition could be caused by the presently installed butt hinges wearing out and ‘bending,’ screws pulling out of worn holes in the door or frame, the mounting plates in a steel door or frame fatiguing – or welds breaking, and other similar catastrophes.

Trying to fix the problem with the same materials that caused this headache in the first place is just absurd.  Instead, use a continuous geared hinge with a careful installation and solve the problem permanently.

If you look closely at the door in Photo 1, you’ll see that the door is leaning hard against the top, right side of the frame while also dragging on the threshold and floor.

This caused the folks trying to get in and out of this 3.5-foot- wide entry no end of problems, not to mention trying to close and lock it; the cover finally popped off of the door closer, too!  You can see the missing patch of tile caused by the bottom of the dragging door.

To solve the problem on this heavy door, a Select  (http://www.select-hinges.com/) SL57 heavy duty continuous geared hinge  was purchased from the local locksmith supplier and taken to the job site for installation. 

First, the area was assessed and examined for all existing problems affecting the door and frame in need of correction. The door closer was removed from the door and the door carefully taken from the frame by removal of the hinge screws from the frame. The existing hinges were then removed from the door and filler plates installed into all hinge cutouts.  

Note: removing screws from older steel doors and frames can prove to be a chore at times because of galvanic corrosion and other debris causing the screws to seize in place; proceed accordingly.  It’s necessary to check and assess door clearances in the frame so that the installation will correct the problems caused by the failure.  Also, upon initial installation, the manufacturer ( Select Hinge) cautions that the door will ‘drop’ about 1/8” as all tolerances come into play when the hinge is loaded with the full weight of the door; accordingly, it’s necessary, when shimming the door for installation to keep the top of the door no more than 1/16” from the frame header to allow for this drop. 

Next, the door was placed in the frame and, using shims and wedges, shimmed tight against the hinge side of the frame and 1/16” below the top of the frame. This allows for a clear 1/8”+ clearance at the lock side of the door and, after installation, acceptable clearance off of the threshold to allow the door to swing freely in the opening.  Your shimming may differ.

The Select SL57HD hinge requires a minimum 7/8” clear space on the frame for mounting and, in this installation, it’s a full frame face so there is at least double that. A normal installation can proceed with the center of the hinge located over the door/frame joint. If this were not the case, it’s allowable for the hinge to locate further over; it will still easily swing the door out of the frame opening, controlled by the continuous gearing. 

The top end of the hinge must be flush with the top end of the door.  All of these hinges are furnished 1” shorter than the opening – ie. 79” for an 80” opening, 83” for a 7’0” opening, etc.    

The Select Continuous Hinge is usually furnished with a screw pack that contains UNDERCUT flat head screws for both wood and metal installations. Depending upon where, and how you placed your order, you can receive 12-24 thread forming, or 12-24 self-drilling thread forming flat head  stainless steel screws for the installation along with wood screws. 

To attach the hinge to the frame, remove the leaf covers, shim the door in the frame as discussed, hold the hinge in the ‘door open’ position and align with the edge of the door frame.  Mark through (at least)  two of the holes at the top and bottom of the hinge on the frame side then drill the frame.  If working with a commercial steel frame at an entry, chances are that the frame will be ‘grouted’ and might even contain concrete as an attaching fill material.  Here’s where you want to have small (5/32”?) concrete bits available to remove this, to make a hole for the fasteners.  Fasten the frame leaf to the frame using the provided screws into the holes you’ve made. 

Next, verify alignment and repeat the marking and drilling process on the door with the provided punch. This time, however, you will be drilling completely through the door using a 3/8” bit, for insertion of the thru-bolt nuts and shouldered screws.  If access to the outside of the door is blocked, FIRST, temporarily attach the door to the door leaf, using the provided 7/32” center punch and four #3 Phillips screws.

Remove the shims and wedges and carefully open the door, checking all the time to ensure that the door is in good alignment and moving satisfactorily. Do not continue until this is the case.  When you are satisfied, install ALL of the thru-fasteners placing the screw head on the protected side of the door.  When completed, again verify alignment and swing.  Install the leaf covers on both leaves and secure in place using the provided set screws and 5/64” Allen wrench. 

Upon completion of this continuous hinge installation, that the door now has all of the available clearance needed at the top, bottom and both sides.  When installing further supporting hardware  such as a door closer, it may be necessary to trim/notch the back of the cover for clearance over the hinge leaf. 

A representative Select continuous hinge interior door installation can be viewed on youtube at:  https://www.youtube.com/watch?v=nlUu4OhS3Ww .   You can also see this and other installation and product materials by going to http://www.select-hinges.com/ .