Replies

1. 
   MarkRD | Mar 11, 2005 12:11am | #1

   I like box joints - no that's not a joke, a box joint is alternating fingers - quite pretty when done well. See the pic below - this is Mahogony and Walnut...

   An early box joint I did (10 years ago)

   Measure it with a micrometer, mark it with chalk, cut it with an ax.

   
2. 
   Patto | Mar 11, 2005 01:40am | #2

   If it is small I like dovetails with a mitred corner inside. So far I have only done these as eight separate joints so that I can see and control the fit of the mitre.This makes squaring up the top and bottom a dit more of a challenge than a single box then sawn apart.

3. 
   4DThinker | Mar 11, 2005 08:27am | #3

   If you don't want it to eventually come apart then box (finger) or dovetail joints will last the longest.  If it's a plywood box and you want finger (box) joints, cut them on the table saw with a jig.  Cutting fingers with a router setup usually chips-out badly in plywood. 

   I make small quick boxes with simple rabbet-dado joints in the corners.  Easier to show with a sketch than to explain.  Looks like butt joints except on top and bottom where you can see the finger left from the rabbet in the slot dadoed in the neighboring side.

   A splined-mitre joint always looks good if you've got a reliable way to cut them.  Don't leave out the spline, though.  It IS the strength of that joint.

   Dave B.

1. 
   MarkRD | Mar 11, 2005 04:01pm | #4

   I like the spline mitre joint too. Though there are two different ways to do them.Version one: the grove runs the "height" of the board and is cut into the face of the mitre - this grove I cut on a table saw.First cut the board at a 45*, then flip the board over and, using your mitre fence, cut the grove in the face of the mitre.
   You'll have to lower the blade or raise the wood...Version 2: The groove runs perpendicular to the mitre(as if you were making a frame) I made a fixture that allows me to feed a mitered piece of stock into a biscuit slot cutter bit on my router at a 45* angle to the slot cutter. You can use biscuits for the slots, or for something prettier, use a contrasting wood (I've used walnut spline in oak and oak splines in walnut both look quite nice. If I had some maple lying around, I would prefer that in the walnut) To make my own spline, I resaw the walnut on the band saw, then plane it to the final dimension. The splines need to be snug because walnut (or any hardwood) won't expand like normal biscuits. Plane the wood thickness close (perhaps 0.005 to 0.010 over sized),then sand them with rough sandpaper just before you insert them into the slot.I cut the splines on the bandsaw with a curve on one side to match the curve in the back of the slot. Glue in a spline (I clamp the miter to a 90* clamping jig and tap in the spline.) After the glue sets up, trim the extra spline off on the bandsaw or with your favorite back saw.A strong joint, relatively simple, and quit nice to look at :-)Mark

   Measure it with a micrometer, mark it with chalk, cut it with an ax.

1. 
   steelheader | Mar 11, 2005 04:39pm | #5

   So if I understand correctly, I cut a slot in the face of the mitre on both boards to be joined, then cut a third piece to fit into the slot. Like a tounge & groove but the tounge is a seperate piece. Is this correct? Thanks, Shane

   This is the exact type of info. I was looking for, I prefer the look of a mitered corner but wasnt sure how to get a strong corner that way.  

1. 
   MarkRD | Mar 11, 2005 05:29pm | #6

   Yes that's right. I realized I didn't explain that type of spline joint.
   third piece of material joins the two - glue the face of the miter and the spline.However, Until I got my planer, I had a hard time cutting the spline to the right thickness. Very tricky on the Table saw since the piece is so thin...HTH, (Hope that helps)
   Mark
   

   Measure it with a micrometer, mark it with chalk, cut it with an ax.

2. 
   georgek | Mar 11, 2005 05:41pm | #7

   I wouldn't use a mitered joint for something as large as a blanket chest. Without addressing strenght issues, getting a splined miter that long to fit perfect would take very precise milling. I would use finger joints.

3. 
   BG | Mar 11, 2005 05:48pm | #8

   Steelheader,

   Just to add to Marks clarification.  Generally, you'll spline two long grain sides together (as in panel and frame construction)...not end grain pieces.. for end grain the box or dovetail joint works best.  Also, remember the spline's grain needs to be perpendicular to the adjacent boards grain for strength.   

2. 
   UncleDunc | Mar 12, 2005 03:19pm | #12

   >> Cutting fingers with a router setup usually chips-out badly in plywood.I haven't done it myself, but it seems to me that you could cut chip free finger joints in plywood with a router if you clamped a backup board to both faces.

1. 
   4DThinker | Mar 13, 2005 07:37am | #14

   > Cutting fingers with a router setup usually chips-out badly in plywood.

   >>I haven't done it myself, but it seems to me that you could cut chip free finger joints in plywood with a router if you clamped a backup board to both faces.

   It depends on quality of the plywood.  I've seen too many time where a poor bond between layers lets the inner crossing layers blow or kick out even if there is a good backer behind the piece.  Even Baltic Birch plywood, which is what we use the most of, varies considerably from piece to piece.

   Dave B.

1. 
   UncleDunc | Mar 13, 2005 10:07am | #15

   Bummer. But good to know. Thanks.

4. 
   Glaucon | Mar 12, 2005 01:37am | #9

   I would favor dovetails.  Box joints would also work- you have less end grain gluing, so you get a better bond than with mitres (but splines do help).  Another option would be sliding dovetails.

   Glaucon

1. 
   MarkRD | Mar 12, 2005 03:01am | #10

   Great, I love the sliding dovetail - something about that joint just makes sense to me...Mark

   Measure it with a micrometer, mark it with chalk, cut it with an ax.

1. 
   Glaucon | Mar 12, 2005 06:20pm | #13

   I agree.  It's the bomb for bookshelves.

   Glaucon

5. 
   Pondfish | Mar 12, 2005 03:45am | #11

   Blanket chests tend to be joined depending on their construction (and no, I'm not trying to make a circular argument!).

   Plain chests (like a siz board chest) can be joined either by mitred corners (spline is recommended) or by dovetails.  You can use a box joint, but dove tails are traditional.

   Frame and panel built chests will use M/T joints to join the panels, though other options are always there.  A chest meant to impress might have the stiles dovetailed to each other.

   If you are just getting started, go with the splined mitre joint, although a box joint would be a reasonable "aggresive" goal that would add the experience of making a box-joint jig.

    

1. 
   Midnight | Mar 13, 2005 11:12pm | #16

   Just to be different... the blanket chest I built was panel construction, panels joined with mitred joints. I used biscuits rather than a single spline... Other than the glue-up being a bear it was pretty straight forward, and with a fair length of long grain to long grain holding the panels together, I canna see it falling appart any time soon...Mike Wallace

   Stay safe....Have fun

1. 
   Pondfish | Mar 14, 2005 12:37am | #17

   Yep, i think that one is going to hold together for a while.