Thursday, September 22, 2016

We Oregonians love our joints

What are you thinking?  I meant woodworking joints, of course.

I began thinking about this subject after my friend John emailed me somewhat defensively about his decision to use box joints rather than dovetails for a carcase he is building.  That discussion was what prompted me to write my recent impertinent post about dovetails being for the birds.  As I thought about it more, I decided to make four boxes differing only in their joinery and rank them according to four attributes:
  1. Speed of construction
  2. Ease of construction
  3. Strength
  4. Appearance
Regarding the 4th attribute, I would ask my wife's opinion as well as noting my own.  She was the one that wanted a box in the first place after all.

The four types of joinery were:
  1. Dovetails
  2. Greene and Greene box joints
  3. Miters
  4. Rabbets
Here are some pictures of the completed boxes:





So, first, ranking them by speed of construction:
  1. Miters
  2. Rabbets
  3. Greene and Greene box joints
  4. Dovetails
Actually, it was more or less two ties, the first two taking about the same amount of time and the second two taking about the same amount of time.  The first two were very fast because of two great tools I own.  My Millers Falls Langdon Acme miter box makes cutting miters extremely fast and they fit tight off the saw.  This thing is a marvel, a truly magnificent design.  If I didn't have one, I would refine miters with a donkey's ear, which would still be fairly fast.  I made the rabbets with my Lee Valley skew rabbet plane, also a wonderful tool.  I cut the Greene and Greene joints by hand and was surprised that they took as long as the dovetails, but that was because you still have to chop out waste and it takes time to pillow the fingers.

Next, ease of construction:
  1. Miters
  2. Rabbets
  3. Greene and Greene box joints
  4. Dovetails
Same order.  With the miter box, miters are ridiculously easy to make and the masking tape trick makes them easy to glue and assemble.  Rabbets are easy enough to make and assembly is just glue and clamps.  Both of these have the additional advantage that you can plow grooves straight through all four sides for the bottom.  Greene and Greene joints are not very hard to make as long as you can saw straight and square and assembly is as easy as the first two.  Dovetails are harder to cut but easier to assemble.

Strength:
  1. Dovetails
  2. Greene and Greene box joints
  3. Miters
  4. Rabbets
Dovetails are obviously far and away the strongest, but the way these small boxes were made and will be used, it makes little difference.  The boxes have a glued-in baltic birch bottom, which adds considerable strength to all of them.  To make up for the lower strength of the other three joints, I pinned them with 1/8" birch dowels from Lee Valley, which I am a big fan of.  In addition, I know from experiments I have done that there is more glue strength in these joints than you might think.  There are other methods of strengthening them even more.  Of course, in other applications the strength of the dovetails can be much more important.

Appearance:

My wife's ranking:
  1. Greene and Greene box joints
  2. Dovetails
  3. Miters 
  4. Rabbets
When I asked her why she ranked them this way, she said she just likes the way the Greene and Greene joints look with the pillowed fingers.  She said everybody knows dovetails mean quality and craftsmanship.  The miters she found nice but plain and the rabbets she didn't like at all.

My ranking:
  1. Greene and Greene box joints
  2. Miters
  3. Dovetails
  4. Rabbets
 We differ only in that I prefer the miters to the dovetails.  I think they look really clean and nice and you can have the grain run around the box.  For the reasons I've given previously, I don't find the look of the dovetails that appealing and the "everybody knows ..." reason leaves me cold.  I don't like the rabbets either.

I am going to be making a number of boxes for presents this winter, one reason for conducting this trial.  I will be making them with ... miters.  I know I should be ashamed, but being able to make half a dozen of them in a day is a key advantage.  As for these four boxes, my wife gets them all.    

7 comments:

  1. Miter first, then dovetail, Greene and Greene, and rabbeted last. Greene would have been second but I don't like the pillowed look of them.

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  2. Andy,

    Interesting test. I guess because I do not have a good miter box or donkey ear I would find the mitered box the most time consuming, The Green and Green I expect would take longer than dovetails for me to do simply because I seldom work with rounded tenons and a simple set of dovetails is very quick. Rebates, what is to be said other than they are rebates.

    Anyway, all are nice and interesting to see how they ranked.

    Ken...starting to rebuild my give away box stock soon.

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  3. How are you cutting the mitres on the mitre box? With the face against the back stop cutting down into the end?

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  4. Almost that way. If you put the inside of the piece against the back of the miter box you can avoid tearout. To get an accurate cut, you have to be really careful to hold the workpiece securely.

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  5. Very good presentation.I prefer mitres also, followed by dovetails.
    Ploughing for bases is a good reason though if you mitre the bottom dovetail you can hide the bottom board dado. Also with dovetails you can get away with different thicknesses of sides, altering the marking gauge to suit. With mitres it is imperative that all sides are the same thickness.
    Regards, Frank

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  6. Very interesting, Andy. Your comment about miter and rabbet joints being able to run the grooves for a bottom panel is really key. Did you run the grooves through for the DT and box joints, and if so, how did you hide them?

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    Replies
    1. Matt,

      Thanks. No, I didn't run the groove all the way through. This box is long and narrow so I ran grooves on the sides and used slips on the end. Cheating, I know, but it worked well.

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