From WoodworkersZone WoodWiki
First of all there are many ways to make these and there is no right way, just whatever works for you and the equipment you have. They are not terribly difficult but can be a pain. First of all, here are the dimensions, however they like many other things are just approx measurements. These are interior measurements, because the outer measurements can vary due to the thickness of the lumber.
First step is to dimension your lumber, the width of the sides are 2 5/8", I believe that is a astehically pleasing width and allows enough room for the flag once inside. Once the lumber is dimensioned to 2 5/8" and approx 3/4" thick you are ready to go. For large flag cases I rough cut the length of approx 20" for the sides and 28" inches for the base, and for the smaller cases it is 13" for the sides and 18" for the base. Once the lumber is milled up, I make the dado for the glass by raising my tablesaw blade(full kerf, not thin kerf) to 1/4" and set the fence to 1/2" then run all the interior pieces through. Next is the rebate(rabbit) for the 1/4" ply that will eventually be the backer. I usually do this on the router making mulitple passes till i get the 1/4" x 1/4" rebate. Once that is done, I usually go ahead and rout the profile on the front of the case while the pieces are still seperate. You can do whatever profile you like but I do a roundover most of the time. Now it becomes time for you to cut to final dimensions. I start by cutting the 45 degree angles on both of the side pieces. Make sure that they line up, remember they are opposing sides so when the two 45's line up, they make a 90 with the rebates and dados lining up. Once the 45's are cut, you have to make the 67 1/2 degree cuts on the ends. Now, I don't know about you, but my tablesaw doesn't go to 67 1/2 degrees. So what you have to do is pull out the tenoning jig and turn the pieces on their ends. In order to get to 67 1/2 degrees you have to set the saw to 22 1/2 degrees.
Here is a better look at my jig with all the markings indicating the cuts for the various pieces. I highly recommend making something along these lines if you plan on making more than 1 flag case. It really simplifys things and helps with the production schedule.
The rough dimensions I gave you earlier were just that, rough. What you need to do to insure a proper fit, is cut both side pieces first, then cut the bottom piece. Cut the bottom piece for a close fit at first, then as needed take off small amounts till you get that perfect fit. You will know what a perfect fit looks like when all you corners line up like this.
Once you found the perfect fit, mark your jig so you may have a reference point for the next time. Before you glue up, sand the insides first, and apply tape to help remove old glue.(Caution, after the glue has become gummy, while still in the clamps, go ahead and remove the tape. If the glue has dried, you will find yourself having a terrible time trying to remove it.
In order to ensure your dado's stay in alignment during glue-up, you need to make some inserts made out of 1/8" ply or other suitable material to help ensure your alignment. Make sure you wax them before you use them, or they will become a permenant fixture to the case.
You are now ready for glue up. I prefer the use of strap clamps(some refer to them as web clamps) because they seem to work the best at pulling the corners together.
Drying time varies across the country but it usually takes 2-3hrs before the glue is dry enough to remove the clamps. After 1hr of drying, remove the inserts, the piece at this point has dried to where you shouldn't have any problems with alignment, and the inserts are still easy to remove at this time.
Next step is to cut the splines for the corners. There are several ways to do this, one being on the table saw and using a jig to cut the splines, the other is a way that I came up with that is quick and simple. In order to do the method that I choose, you will need to have a router table and a slot cutting bit. Any size slot cutting bit will work but I think the 3/16 bit is a pleasing size for flag cases. You will need two sleds for my process, one to cut the 90 degree angle and the other to cut the 135 degree angle.
Once all the slots are cut into the case, you need to make some splines/keys for the voids. When making the splines try to make sure that they are snug, but not too tight. If they are too tight, you might have to force them when glueing them up. The splines can be any wood, I sometimes use contrasting wood to mix things up a bit. When making splines, make extras of varying materials and test to see which ones look the best.
Insert splines into the slots using plenty of glue. Use either clamps or tape to make sure splines stay in place till the glue dries.
Once the glue has dried on the splines, it is time to clean them up with the bandsaw and remove the majority of the material. With the bandsaw, try only to leave about 1/8" of excess material. Once all the splines/keys have been trimmed, move the case over to the router table. With a pattern bit in the router table, rout the splines/keys flush with the case. At this point, you should have all the splines perfectly trimmed and now it is time to move to making a slot to insert the glass.
To insert the glass into case we are going to need to cut a slot on the bottom of the case. Cutting the slot is an easy operation with the proper tools. In order to accomplish this task we are going to need a 1/4" spiral bit set about 1/8" above the table. Set the fence so that when the 1/4" slot is cut through the bottom, 1/16" material is going to be to either side of the glass slot. Start by removing 1/8" inch of material, and then slowly raise the bit with each pass till you pop through to where the glass slot is. Depending on how thick your material is, this may be up to 1/2" deep slot.
The next step involves cutting a filler strip to fill the slot you just cut to allow access to the glass. You can do this many ways but I found an easy way to do it. First you need some filler strips. The need to be long enough to fill the slot you just cut on the bottom of the case, 1/4" thick and about 5/8" inch in depth. Once you have milled up your strips, you need to rout one end to make a round corner. I use a 1/4" beading bit in the router table. Be sure to use a feather board to keep your material down flat.
Once you trimmed one end with the beading bit, you will now need to do the other end. I usually insert the end I just routed on the table into the slot and mark where the other end runs long. I remove the majority of the material with the band saw, then go back to the table and rout the other end. Once both ends are perfectly routed, the strip should fit snug with no gaps. Your strip will probably be about 1/8" proud of the surface at this time. At this time, sand the plug flush. Once plug is flush, the only way to remove the plug is from the inside of the case. I use a either a small scerwdriver or the wrench that comes with my web clamps. The plug should come out with moderate pressure. If you have done the operation right, your filler plug should look like this.
Next you need to make a backer piece for the case. I use 1/4" baltic birch ply for this. Simply place the case on the ply and trace the outline of the filler piece. Cut the piece to fit.
Now it is time to finish your flag case. You can use any finish you like, I use a simple Danish Oil finish for ease of application. Once your finish is dry, it is time to complete your case.
You can either cut your own glass or pay someone to do it. I cut my own glass because I find it more convienent then having to wait for someone else to do it. (*** Cutting glass that fits right can be tricky. Not that the process is hard, but the glass has to be exactly the right size. In order to do this correctly, here is the process I recommend.***) The glass I usually buy comes in varying sizes but is always rectangular in shape. I insert one corner of the glass all the way in to the flag case. Once glass is inserted, I mark the inside bottom of the case. Remove glass, and add about an 1/8" to that bottom mark. Cut glass and insert it into case. Take a look at the bottom where you inserted the glass, the glass should not be protruding and your plug should be able to be inserted all the way without it sticking out. If this is the case, then you are ready for a few dabs of hot glue and insertion of the plug. The plug all alone should be able to hold the glass without a problem, but i find the hot glue helps the glass from rattling, and the extra strength of the glue doesn't hurt.
Use 6 brass screws to attach the back 1/4" ply to the case.
The process is complete! Enjoy!
Special thanks to Timbeck2 and MStens for their help in the design of this project. Without their help many beers would have been left full, unfulling their lifes ambition.