We now have our box assembled and glued up. Depending on the temperature, let it dry for a couple of hours, or overnight to be safe.
Take the tape off and clean up any dried glue.
This is a good time to smooth up the bottom to get rid of any rocking.
You can double stick sandpaper onto a very flat and firm surface and slide the bottom across that. The problem with this approach is that sheet sandpaper is way too small. You can stick down several sheets and if you go very slow, you may not tear the paper.You can also use a sanding block or a hand plane. I have a Jet 6×48 belt sander/disc combo, but is just not quite wide enough.
I decided there had to be a better way.
I work for a cabinet shop,( in the office only, where I design and blah,blah,blah) and we have a 36" wide Time Saver sander. We toss the belts after they are worn out but I knew they had a little life left so I snagged one to make a sanding platform. After a little trial and error it looked like this:
I use it for the bottom, top and for leveling out the sides after cutting off the splines.
The belts I get are 36'' wide and a 60'' loop. I split them in half lengthwise ( they rip very straight after you get it started with a cut from a razor knife.)
and that gives me a sanding surface of about 18×24.
Do not try ripping these on the table saw…kids!
The angle of the sanding bed gives a nice working position and the ell leg lets it hook onto the edge of a bench, keeping it in place. ( I am sorry but the ell leg I am refering to is not shown in this photo, its at the operators end, its not the one to the right in the picture.) The taper lets the rod progressively tighten the belt by wedging it in place. Simply pull the rod back and the belt slackens so you can rotate it to a new clean section.
There is still enough life in these belts for this purpose. Just check with a local cabinet shop and offer them a few bucks for discards. They will probably just give them to you, but you may get turned away if you go asking for a handout.
Or you could order a new one from Klingspore
They sell this same size but they also have a 17" x54" and they cost about $33 plus s&H
we are going to cut for the corner splines (aka slip feathers or corner keys ).
Layout, and how many you use is strictly up to you. You can just place them randomly if you wish making each corner unique.
If you are going to really do some wild shaping then placement isnt that critical, since your eye wont be able to align one side with the other anyway. Maybe after a few drinks you might be able to.
This is the layout we will use for this box. The reason the top spline is placed further from the top edge than the bottom one is from the bottom edge, is that this will allow for more aggressive shaping of the top without getting into the spline too much.
Another reason, is that if you are going to make a box that has a lip on only three sides of the lid to nestle into and you will be using butt style or barrel hinges, then this will ensure the cutout for the lid at the back doesnt cut
down into the splines.
This will become clear a little later on.
If I want the center one to be exactly centered between the top and bottom ones, I dont measure its location ne until I have cut the bottom and top kerfs. It easy to be off a little when allowing for blade thickness, etc…
Here is the layout I used, but yours can be whatever you want.
Here is my corner spline jig that rides overtop of my saw fence. It cant move to the side ensuring a straight cut.
I placed sticky back felt on the inside surfaces so it slides freely.
There are several other versions on LumberJocks to model yours after.
For clean flat bottom kerfs the correct saw blade is important. I bought a flat grind toothed blade by Forrest since all I had was a selection of ATB ones which leave a veed or angled bottom. I would carefully try and flatten the bottoms with a file, but it was very difficult not to mess up the sides. I understand why some still use an ATB blade, its a chunk of money for a blade that I only use for kerfs.
If you arent sure what type of blades you have, do a test by cutting shallow kerfs in a board with each one, you might just have a flat cutting blade on hand.
You will get better looking kerfs if you only push the box through the blade once, and do it like a machine.
Stop after you go over the blade and raise the box up to clear the blade before pulling it back through.
It doesnt take much…a little wiggle…a little sideways pressure…or even a blade with poor runout, and you will get a sloppy cut. Even a little slop is visible when you glue in a spline that contrasts with the box.
Thats the whole idea isnt it, to draw the eye to the splines?
So do your utmost to make them crisp.
Next we need to cut some splines and I have decided to use Maple for this Bubinga box.
There are several methods for doing this, including an adjustable stop that sets to the left of the blade. You can also rip them on the bandsaw and run them through a thickness sander, and you can even take your chances with a planer to size them if you wish but they usually just spit it out like scrabble pieces.
This is my approach and it works very well for me.
As you can see it is simply a push stick with a heel, a good handle, and a flat side that rides against the fence.
I set the blade to the approximate width of the spline and make a pass or two until I get it just right testing with some scrap wood. Yes, the thin strip is between the blade and the fence but is prevented from shooting out the back because of the matching heel on the push stick. Just be sure and use a good wood with an intertwined grain such as this White Oak one shown here so the heel doesnt break off too easily. Its a little scary at first, but its safe.
Test your splines!
Slide them in and out to be sure they are snug, but not so tight that you need to force them in while they are still dry. They will swell pretty quickly with glue on them and they may not even bottom out. Its a fine line between too tight and even a little too sloppy. A loose fit will mean that you will see the glue around the spline.
Cut the splines to about 1 1/2'' long using a handsaw or bandsaw. I always cut extra so I wont be tempted to use one thats too tight or too loose. Now you are ready to start glueing them in the slots.
It is very easy to mess this up!
Dont get in a hurry, and do one at a time. Quit texting your girlfriend and focus!
Use a small brush to apply the glue. ( I use acid brushes for soldering. They are natural animal hair and can be used over and over. They are cheap too. I cut the bristles shorter with a chisel and mallet.)
Have a wet rag at hand to wipe away excess glue and another acid brush to clean around the slots, just to be sure the splines are seated all the way to the bottom of the slots. You may need to coax it into place with a mallet.
Do this slowly and carefully on each one. And, be sure you dont bump the others out of position.
If there is any gap anywhere, it will show when you trim the splines flush. Not much you can do to fix it. So, be careful.
After you have them all done, give it an hour or so to dry and trim them flush. I have a 14" bandsaw, so I can just fit one of these boxes through to trim off the ends. A handsaw will work too. So will a trained beaver if happen to own one.
And then on to the sanding platform to flatten the sides. It doesnt really need to be pretty, just flat for referencing off of a fence or measuring for hinges, etc.. The sides of this box will be shaped anyway, so dont waste time on getting all the marks out…unless you want to….which I usually do