David's
Compact Computer Desk

In this step we will mount the drop front door.  As you may recall, we had some trouble with the hinge/supports that I ordered -- they would not let the door lay flat as it should.  I checked with my vendor and was told that all such hinges they had in stock were made the same way, and they had no other brand or version.

So I sent those back and ordered a pair made by another manufacturer from another vendor.  These lay just as flat as you please, but there are some differences.

The first pair were antique brass finished steel, they had the knuckle of the hinge made in line with the hinge straps, and they cost about $15.00 per pair.  Because the knuckle protruded below the strap of the hinge, I needed to cut small mortises in the edge of the cabinet bottom and the door that the knuckle could fit into so the straps would lay flat on the wood.  The straps were thin enough that I didn't really HAVE to mortise them into the wood to get them to look right.

The new ones are solid cast brass, with a polished finish and cost about $40.00 a pair.  They do lay nice and flat and would not require the knuckle mortises (that I've already cut) but they are thick enough that I will need to mortise them into the cabinet floor and the door to keep them from looking "clunky".  Doing this will also eliminate most of the knuckle mortises I cut.  But there is one other thing...

Because of the top mounted knuckle, when the door is closed, the hinge LIFTS the door rather than simply pivoting it through the center of the hinge.  This leaves an obvious gap at the bottom of the door.  Mortising the straps into the wood will reduce this gap by 1/8", or about 1/3 of what you see here.  Something more will need to be done.

After a great deal of thought and hair pulling the only thing I could come up with was to cut a bevel on the lower edge of the door and a mating bevel on the front of the floor.  These will allow the two parts to snuggle up together nicely, but when the door is closed the "lip" will stick down and hide the gap.  David's nephews will not be able to keep their pet crickets in this desk because the gap will let them get out, but at least it won't be so obviously visible.  This desk was designed to use a pair of flat butt hinges, backed up by support chains to hold the door level when open.  By eliminating the chains and going with the support/hinge combo we opened an unexpected can or worms.

Hmmm... crickets, worms, seems to be a theme working itself up here.

OK, so the first thing to do is to chuck a 3/4" wide straight cutting bit in the router.  This will cut the mortise for the hinges in one pass and leave a round-end mortise that will fit the round ends of the hinges.  But, I dare not just plunk the router down and try to guide it by hand or I'd have a terrible mess as a result.  I could use an edge guide to keep the router going in a straight line, but the length of the cut will be critical if we are to achieve a nice snug fit with the hinges.

So we need to build a routing jig to help us do a good job of this.  The jig consists of a pair of L shaped rails, the router base plate rides on the lower part and the lips are just barely wide enough to allow the base plate to slip through.  This needs to be snug enough that there is no slop, side-to-side slop will mean a mortise that is lumpy or crooked, but too tight and it will require excessive force to get the router to move along the jig, and that could shift the jig's position and ruin everything.  A nice, snug fit is what we want.  A tail block serves a a "hook" that will fit against the edge of the piece being routed to hold it from sliding and the head block is fitted with a screw to provide a micro-adjustable stop so I can achieve the perfect length in the cut.

Once the jig is built, I test it on a piece of scrap plywood.  I test and adjust the stop screw to get the right length and the depth of cut using a hinge fitted into the scrap piece.

When it's right, I take a deep breath, say a little prayer and cut the the first mortise in the desk floor.

I use the test scrap and a hinge to check to be sure everything lines up properly, then cut the second mortise in the floor.  Then I lay the door in place, flush it up at the sides and mark the location of the hinge mortises on the door using the mortises in the floor.

Before I can cut those mortises though, I need to bevel the edge of the door, then I can measure the proper length for the mortise and set-up the jig to cut it.

Cutting the mating bevel on the case requires that I first attach the sides to the floor and cut them as a unit.  Cutting an assembled case is uncomfortably ungainly.  Another little prayer is said, "Lord, please don't let me mess this up!" I'd hate to have to start all over.

They say the proof is in the pudding, so let's taste the pudding.  Will you have worm or cricket flavor? The door fits nicely against the floor, the hinge mortises are perfectly aligned and fit like gloves.  It could not have come out any better!  (Thank you!)

Next we need to install some magnetic catches that will hold the door closed.  these are little button magnets in a ridged plastic sleeve and the fit into a stepped hole, 5/16" for the barrel, 3/8" for the rim.  They probably intended that the rim would sit on the surface, but that would leave too much of a gap.  Small steel disks are recesses into the inner face of the door to complete the set-up.  I installed one pair and tested them, but didn't feel they had quite enough "stick" so I repeated the process and installed another pair as reinforcement.

The final obstacle to overcome is the fact that I supposed to be using antique brass hardware and the hinges are polished brass.  I'll remedy this with two vats, a piece of soft cloth, a pair of rubber gloves and a bottle of selenious acid solution, and a couple pieces of antique brass hardware to use as a color comparison.  The hinges go into the first vat, fresh clean water go into the other.  I pour in enough of the acid solution to cover the hinges.  It doesn't take long, and once they start to darken, they get dark fast.  When the proper color is achieved, take the hinges out of the acid and drop them in the water, swish them around a little.  A little baking soda in the water helps to neutralize the acid.  Then take the hinges out of the water, let them drip a moment then dry them with a soft cloth.  Some oxidation will rub off, if you got them a little too dark, rub harder and rub more oxidation off.

From bright brass to antique brass in just minutes with the proper application of chemistry.

Before I can mount the door for good, I need to attach the top struts to the case work, these will have a good deal to do with holding the case in shape.  So I glue them up and clamp them in, then measure across the diagonals of the front and moosh one in a bit (1/16") to square up the front face of the case so the door, which is already square, will fit to it nicely once we're all done.

I'll let this assembly set up overnight to be sure the glue hardens before I remove the clamps.

In the morning I remove the clamps, attach the door and test the movement, closing position and the magnetic catches.  In case you're wondering; no, the cubby assembly is not in it's final position.  It is just sitting in there to be sure I didn't "tweak" the case during clamping to where the cubby assembly wouldn't slide into position.

And that does it for the door.

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