"Art Box" Tutorial #4: Splines

We now have our box body assembled and glued up.Take off the tape and clean off 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.

Tip:
I designed this sanding platform for leveling boxes and flushing out the corner splines.It uses discarded belts from a commercial thickness sander.

The ones I get are 36’’ wide and a 60’’ loop.I split them in half and that gives me a sandpaper surface about 18×24.The angle gives a nice working position and the ell leg lets it hook onto the edge of a bench,keeping it in place.The taper lets the rod progressively tighten the belt by wedging it in place.Simply pull the rod back and you can rotate the belt into a new clean section.
There is still enough use 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 here.

http://www.woodworkingshop.com/cgi-bin/944DB2F2/mac/additmdtl.mac/showItemDetail?item=WB64172&qtyA=0&phsO=N&desc=37%22X%2060%22%20ALUM%2E%20OXIDE%20180%20GRIT%20Y%20WEIGHT&drpshp=N&alOrd=Y&iQty=.000&oQty=.000&initQty=1&assortParent=N&itemForSale=Y&styleName=&fixD=&face=.00&gftc=&stck=Y&prefS=&calledFrom=DS&ordInfo1=&ordInfo2=&ordInfo3=&ordMan1=N&ordMan2=N&ordMan3=N&persCode=&persReqd=&persLink=%20&shipRemaining=0&daysBetween=0&daysBetweenFix=0&monthsBetween=0

The results in a few strokes.

Next we are going to cut for the corner splines (also called “Slip feathers”,corner keys ).
This is the layout we will use for this box.The reason the top spline is placed further from the edge than the bottom one, is two fold.
The first reason, is that this will allow for more aggressive shaping of the top without getting into the spline too much.
The second reason, is that if you are going to make a box that has a lip on only three sides and will use butt style hinges,then this will ensure the cutout for the back doesnt cut into the splines.
This will become clear a little later on.

Tip:Dont measure for the location of the center spline until you have cut the bottom and top kerfs.

There are several jigs posted right here on LJ that will work just as well as this one.

Tip:
You will get better looking kerfs if you only push the box through the blade once.Stop after you go over the blade and raise it up to clear before pulling it back.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.
Use a good sharp blade and preferably one with a flat grind like this one from Forrest. I finally got one of these and dont use it for anything else.It is sweet!! I use to cut them with ATB because thats what I had,and then I would carefully flatten the bottom of the kerfs with a file.A real pain and the results weren’t consistant.

Tip:
Here is an easy way to set the saw blade to the correct height.Take a piece of wood 3/4’’ thick and lay that in the V of the jig,positioning it like you would the corner of the box and run it through the saw.The resulting kerf will just pass through to the edge of the board when the height is correct.

You can make wider kerfs if you wish just by resetting the fence and making two passes.
Wrap tape around the box where the kerfs land,this will prevent tearout.I dont worry about that if I am going to do any shaping on the exterior.

Here is what your box should look like at this stage.I make these 3/4’’ wide.
(I dont mean total length of the kerf,but the actual width of each face.)
Take a look at the photo below and the width of the kerf in the tape is what I mean.
You will need to make test cuts to determine the correct height depending on your jig.

Next we need to cut some splines of a contrasting wood and I have decided to use Maple for this Bubinga box.
There are several good methods for doing this,including an adjustable stop that sets to the left of the blade,rip them on the bandsaw and run them through a thickness sander,and you can even take your chances with a planer.This is my approach and it works very well for me.
As you can see it is simply a wide shoe style push stick with 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.I do this on some scrap wood.The spline 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.

Next,lets cut the splines to about 1 1/2’’ long on the bandsaw(safer).Test fit each one,to each slot.They should just slip in all the way to the bottom without any slop ,nor should they require much more than a light tap.Brush glue on them, one at a time and tap them into place,making sure they seat all the way down tight to the bottom of the kerf.Move quickly,because as the glue soaks in, the splines start to swell up.

Tip.It is very easy to mess this up.Take another small acid brush and clean away the excess glue to be certain that the spline is in full contact against the box on each side.Do this slowly and carefully on each one.And,be sure you dont bump the others out of position.
If there is any gap it will show when you trim the splines flush.You can sometimes cut little pices of matching wood and tap them into place,but if there is dried glue in the pocket,then you are in a pickle.Not much you can do to fix it.So, be careful.

Next.After the glue dries for about an hour we can cut off the excess wood.I prefer to use the bandsaw,but a small handsaw will work well too.Just leave a little sticking out, and then sand that flush.

After sanding you should have a box that looks something like this.

If your box doesnt look this good,dont get discouraged.Just move on to the next phase.It will all make sense in the end and your next attempt will be better.

DO NOT CUT THE LID TO SIZE UNTIL YOU ARE SURE OF THE STYLE OF BOX YOU WANT TO MAKE!

Next phase will be routing out the recess for the top.

-- " If I can make it,so can you" Andy in Oregon