Overview: In the last blog I detailed how to separate the top from the box and how to start with a long piano hinge then size, cut, polish, round, crimp, smooth, and paint the hinge so it will fit any size of box.
In this chapter I will explain how to install a piano hinge in a box. We will go through how to mortise, fit and fasten the hinge. The essential tools are: router table, small try square, vix bit, drill and impact driver. If all goes well, it should look like this when you are done.
Centering: Exactly center the hinge on the back of the box using a try square. Move a small try square from left side to right side. Adjust the blade of the try square in and out until the end blade of the try square just kisses the hinge on both sides. No real measuring is needed.
It may take a few tries making fine adjustments and going back an forth, but when you are finished you will have your hinge in the exact center. Now lock down the stock of your try square to preserve that measurement. We are going to use this measurement to set up the router fence.
Fence Location: As you can see I use a simple clamping straight edge as a fence for this. It is light, easy to move and change, and stays in place. (Remember, when you are setting a router fence like this, all that matters is the distance between the fence and the cutter. If it isn’t straight so what? The bit is round so straight isn’t important, distance is.) With the head of the straight edged cutter bit turned so the longest point is closest to the fence, align the cutter with the stock and transfer the measurement you took when centering your hinge to be the distance between the fence and the point of the cutter. This needs to be an exact match and you should sight down the head to get the exact point of the cutter at the edge of your try square head. Bring your fence over until it touches the blade of your try square and lock the fence in place. With good light and some care this can be a very exact measurement…and it needs to be.
Cutting the Mortise: What I didn’t think to picture was setting the bit height. Put your hinge on the table and raise the bit until the top of the bit is at the exact center of the pin of your hinge. Since this mortising is all I do on this table, I leave it set for the hinges I buy.
Now bring your box down the fence to cut a mortise. Notice two things: One, I marked the back side with chalk so I don’t screw up and cut the mortise on the front side. Two, be sure your table and fence are free of sawdust. Any dust between the box and the fence will throw off your measurements. Now reverse the box and cut the other end of your mortise going along the fence from the opposite side of the bit. Thus, you have cut both ends of your mortise and now all you do is freehand cut the waste wood between the two exact ends.
This shows cutting between the end cuts. Be careful not to cut too far. Listening for the end of the cut helps. (Of course if you were using 3/4 hinges and a 3/4 inch bit, you would be done and not need to cut out the waste.)
Repeat the same process for cutting the top. First cut the ends…
Then cut the waste between the two end cuts.
The Completed Mortise: This shot shows the top and the bottom of the box held together so you can see the completed mortise. The ends match nicely, the mortise is evenly cut, and now you are ready to insert the hinge.
Install The Hinge: Here you see the hinge set in the mortise. If you have worked carefully (and are a little lucky) the hinge will be a nice snug fit. Install the hinge starting on the bottom of the box. This shows the reason. You can reach across the box and use your wrists and palms to hold the box down while you work. This is a good time to sand the inside and outside edges of your mortise to be sure there are no splinters to catch unwary fingers (like yours)...before you start putting the hinge in place.
Use a Vix Bit: A Vix bit is a must. This bit centers the screw-hole you are drilling in the center of the hole in the hinge. Don’t just set the Vix bit in the hole and jam the bit into the wood. Let the bit spin in the screw hole then while it is spinning lower your bit into the wood. Spinning the bit first lets it get better seated and you will have better results.
Drill One Or Two Holes In the Bottom: First put just one or two screws and screw holes in the top. Don’t drill all the holes yet. If you missed the mark you can still make adjustments using the other holes to straighten it up.
Put One or Two Holes in the Top: Check your fit. If it is just very slightly off you can sand the outside of the box so they match exactly. But if the sides and front don’t match well, remove one or two screws and get the fit right. Here again it is a help if you have a back-rest to lean the bottom against so you can hold it in place and it gives you two free hands to work with.
Check the Fit: See if the sides and front match. If they do match, carefully open the box and install a few more screws and then check the fit again when you work on the bottom. It helps if your work station has some kind of rest to let the open box lean against so you have two free hands to work with.
Now drill and install all your remaining screws. I like to use an impact driver. It takes a bit to get the right touch with this tool, but it is far less likely to strip out the screw heads and brings the screws down snuggly.
Hinge Completed: If all has gone well, your finished hinge will look like this on the outside of your box. As you can see here, I sand the back edges at the back corner to be sure the box will swing to 90 degrees
The next time I am daft enough to take on a pictured blog like this I will be writing about this sanding station. Who knew it would take 6 sanders to make a box? But it is much quicker than changing Velcro paper.
-- Big Al in IN