How to Install Butt Hinges
Installing Butt Hinges
Learn Fine Woodworking contributing editor Garrett Hack’s time-tested technique for installing what is perhaps the most popular hinge style.
When it comes to searching out a hinge that offers durability, clean looks, and straightforward installation, Garrett Hack feels that “you can’t beat butt hinges.” While woodworking catalogs offer a wide variety of styles, finishes and sizes, when it comes to fine furniture, Hack opts for high-end brass hinges. Low-cost hinges are made by pressing thin sheet metal around the pin to form the knuckle, which results in a sloppy hinge action. The higher-end extruded hinges are much tighter since the knuckle is fitted together and then drilled in one shot for a more precisely fit hinge. And while steel is certainly stronger, brass hardware generally looks better on fine furniture, developing a pleasing patina over time.
Laying Out the Hinge Mortise
Use marking gauges and a marking knife to make precise layout lines. Take all of your settings directly from the hinge for accuracy.
1.) LAY OUT THE WIDTH
When laying out marks, set the mortise width slightly less than the width of the leaf to the center of the hinge pin, to make the pin and knuckle protrude just a bit.
At times, I mortise the case or the frame first, before they are glued, and then transfer them to the door later. It’s easier to work with case pieces loose on the bench than it is to wrestle with a large cabinet. The cabinet picured here, however, is small, so I mortised the door first.
Set the first marking gauge for the width of the hinge. Set it about 1/32-in. short of the center-line of the hinge knuckle. The light pencil lines at the end of the mortise indicate where to stop the marking gauge cut.
2.) LAY OUT THE DEPTH
When making your marks, keep in mind that the goal is to produce very fine lines; heavy cuts will leave a less precise mortise.To see the knife marks more clearly, sharpen a pencil to a very fine point and drag it along your scribed lines.
For situations like the one seen here, where you’re marking so close to the edge of the stock, it’s much easier to use a smaller, specialty marking gauge made for finer work.
Set a second gauge for the depth of the mortise. If the hinge leaves are tapered, be sure to set the gauge at their thickest point.
3.) LAY OUT THE LENGTH
After scribing the width and depth with marking gauges, lay the hinge in position and cut a precise tick mark at both ends. For small cabinet hinges like these, the safest way to lay out the ends of the mortise is to extend these tick marks with a square.
For larger hinges, like those used in passage doors, it’s better to use the hinge itself to lay out the ends of the mortise. Just be careful the hinge doesn’t slip while you are marking.
Again, use the hinge itself to set the length of the mortise. Holding the hinge in place, cut tick marks into the corner of the door stile. Then carry those lines across the mortise with a square.
Cutting the Hinge Mortise
Whether by hand or by machine, the idea here is to clear out the bulk of the mortise while staying clear of your layout lines.
1.) HOG OUT THE WASTE
Chop it out with a chisel. Using a chisel, make a series of chopping cuts in one direction, then remove small chunks of wood by chopping in the other direction.
Or rout it out. Set the bit depth to the thinnest part of the hinge and stay clear of layout lines. For thin doors, you can clamp on an extra board to help support the router base.
2.) FINE-TUNE THE MORTISE
Finish off the mortise with a sharp chisel. Chop and pare gradually until you reach your layout lines and get a good fit. Save your widest chisels for the final cuts.
To protect your fingers and prevent blowout on the opposite side of the door, notice how Hack uses a small piece of scrap to back up the stock.
Mark Hinge Location on the Carcase
Cutting the mortises in the carcase is exactly the same as in the door stiles. The key to this step lay in properly transferring the door hinge locations.
1.) ATTACH THE HINGES TO THE DOOR
Mark for the center screw. Offset this location slightly toward the back of the mortise. This causes the hinge leaf to be drawn tightly into place, against the rear mortise wall.
Drive in one steel screw. This leaves two hole locations unused to allow the hinge to be adjusted in or out later. Use a steel screw to avoid damaging your softer brass ones.
2.) MARK THE CASE
Transfer the hinge locations to the case. Cutting the mortises in the carcase is exactly the same as in the door stiles. To transfer the hinge locations from the door, slip or wedge the door into position with the hinge fully open and make fine knife lines along the top and bottom of the knuckle.
Quick Tip: A spare hinge of the same size makes it easy to test-fit the mortise and to mark the screw locations. Otherwise, you have to remove a hinge from the door.
Installing the Door and Checking the Fit
A typical problem is that the gap along the hinge line is too large or uneven. The solution is to mortise in one or both leaves of each hinge slightly deeper. Of course, the opposite can happen as well. At times, you’ll need to shim a hinge either up or out.
Cut the mating mortises and attach the door. Use the same techniques you employed for the the door mortises and continue to use only one steel screw at this point. Check the fit of the door. If necessary, remove the door and plane it to fit.
For more tips on building solid doors for your furniture, be sure to have a look at Andy Rae’s free download on Building Doors and Drawers.
Quick Tips on Final Adjustments
Adjust the countersinks. One of the final steps to fitting the hinges is setting the screws. Each hinge is drilled and countersunk for a specific size screw, which is often noted in the catalog description.
If the countersinks are not deep enough, the heads of the screws will stop slightly proud of the hinge leaf. This can cause a hinge to bind and exert leverage on the screws. If necessary, deepen the countersinks so that the heads end up just below the surface of the leaf.
|Make fine adjustments – shimming up. If you’ve cut too deep, you’ll want to shim a hinge outward by trimming a card to fit into the bottom of the mortise.|
|Make fine adjustments – shimming out. If you’ve cut too wide a mortise, you’ll need to move a hinge out toward the front of the case. Plane a sliver of long-grain wood to fill the gap at the back of the mortise. Glue it in and plane it flush for an invisible repair.|
If your hinges are installed correctly, your doors and lids should swing sweetly for many decades to come.
More to Come
Be sure to check back in the coming weeks for the second installment of our hinge guide. Next up: knife hinges. And for more information on Garrett Hack’s method for installing butt hinges, be sure to consult his article from FWW issue 159.