# LOCK MITER corners



## Ravenseye (Apr 2, 2006)

Lock miter as in the miter cut with the rabbet joint built in? If so, I don't see a problem although half blind dovetails and lock miter joints are still somewhat of an overkill in my opinion. Even simple joints are fine if you glue and fasten well. I've gone to using wide crown staples in my box joint boxes along with gorilla glue or titebond III. If the boxes are square when I assemble them, they tend to stay like that. If you do use a lock miter corner, be sure that the edges are nice and straight. A single bowed edge will mess up more that one corner if your cuts are close tolerance.


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## BeeCurious (Aug 7, 2007)

Blitzz,

Is this what your talking about? http://www.garymkatz.com/TrimTechniques/lock_miters.html

I see exposed end-grain as the weak point of all boxes. Rabbeted would have approx half the end grain as finger joints. 

And lock-miter... No end grain.

This would be nice for the craftsmen. I've got a cheap saw and I'm banging screws in with an old rock... (or at least it seems like that at times)


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## Blitzz (Feb 13, 2009)

That is it!

All info I have found is with the miter going with the grain and not at
end grain and that is my concern.


Would it work as well there?


This is another really good example with plywood.

Pool Table Build - Part 1 - Using the lock miter bit to create the leg columns
http://video.google.com/videoplay?docid=-2323211353866234211#


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## raosmun (Sep 10, 2009)

With just a table saw, the rabbit joint, good glue, an old ROCK and #6 or #4 galv. common nails or screws work just fine!! Hard to get the screws in with the ROCK  If you have more time and equipment (biscut cutter) then do 45's, biscut or dowel and glue - nail or screw. Too much trouble for a BOX!! 
I have found that "Big Box" store miscolored "deck stain w/preservative" works quite well. Except it takes several days to cure/air-out (two coats).


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## Blitzz (Feb 13, 2009)

How many clamps would I have to buy for rabbet joints?
8/box?
Days to wait till glue cures hard so the corners do not separate when removing clamps?
a will need a good arsenal of clamps.

I have some boxes with rabbet joint and they tend to cup and separate more easily then this creates a weak joint with rhomboid boxes for more rework.

Cutting the lock miter is just as much work as cutting the rabbet joint with a router table.

If you want the easiest way would be but joint with pocket holes (like kregs) and glue then again the pocket holes have to be plugged(no hideouts for pests) you will need also long shaft screw driver and the special screws(I have some like this too).

I like the half dovetail joint(with a jig) but it takes too much time and chances of misalignments is an issue(have some like tis too).


The main question is about the end grain wood and lock miter joint to be more precise.


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## iwombat (Feb 3, 2009)

In my opinion, end grain is not the weakness. It's lack of surface area for the glue. This is why box (and dovetail) joints are so strong, and rabbet joints will often fail.


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## brac (Sep 30, 2009)

I use a rabbit, along with glue (sometimes TB-2, sometimes gorrilla) place in jig to square, add 1/2" wide 1 1/2" long staples. Job done. 
I use 12 clamps per med. box. Clamp = crown staple
there is no movement once they get stapled.


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## HVH (Feb 20, 2008)

I don't see the locking miter as having anything but endgrain. If you look at the earlier link the piece shown has long grain exposed by the cutter but the mating surfaces are all met with end grain from the other piece. The locking miter improves glue surface area and is probably very strong. Box joints have end grain-to-end grain surfaces which are even stronger. 
There have been many post on this forum where posters have indicated a preference for TitebondIII and even go as far as to point out a study where TitebondIII was shown to be stronger than the polyurethane glues. I don't doubt this conclusion, but for making bee boxes I much prefer the poly glues because a judicious application caused enough foaming to fill all the joint with some left to spew beyond. Protecting the joint from water is critical, and the foam makes a protective seal around the joint. Some end grain on the fingers still need to be protected with paint of you want them to stay dry. Any water that gets into the joint will cause expansion and contraction, which will weaken the joint over time. 
I use roofing staples to hold the joint together while gluing and have found that the force from these larger staples has a tendency to pull the joint together. If I didn't have the stapler, and didn't want to use a million clamps then I would probably use the TitebondIII because it sets up much faster. Also, the poly glues are a sticky mess that you have to put up with if you like the benefits. Since I am lazy, I like to use box joints with poly glue, roofing staples and a few coats of high gloss exterior alkyd paint. By lazy, I mean I don't plan on building the same box twice. I have also found that I can save a little time and money by mixing a good oil base primer with the high gloss alkyd. The oil base paints are good because they penetrate the wood. If they take all week to cure, though, it can drive one nuts. So by mixing the two paints, you keep the high solids content while adding a little extra hardener. My boxes are usually dry enough the following day (in summer) to handle. They should be stacked in an alternate pattern, however, or you will be prying boxes apart later.


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## Ravenseye (Apr 2, 2006)

Exactly HVH. I too like poly glues because they foam up and I love staples instead of nails. I MUCH prefer oil base finishes but settle on oil base primers and latex type top coats. I've got oil painted boxes that are in great shape with latex boxes needing work much, much sooner. Too bad there's so little oil paint around now. It's a far superior product. I have a 200+ year old house and nothing else goes on it. So, no matter what you end up with for joining wood, a good finish is a good bet.


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## RDY-B (May 20, 2007)

Only problems i can see would be if you did not assembly right away and the wood swelled or shrunk-making assembly difficult -I imagine thats why they arnt used for production-they call it a inherative nature indicative to wood
 looks good though give it a try  RDY-B


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## PeeVee (Dec 10, 2009)

I've been using lockmiter corners. 1/2" shaft on a router table. There is no way to run this bit without a table. 

Once set up, the process goes pretty quick. You do need a firm grip but if you have been using routers and tables you already know that.

The joint is pretty much self squaring. I use titebond 2 or 3 (whichever I have at the time) and 1/4" crown staples from both directions.

I made a mistake in measuring one day and the only way to salvage any wood was to cut down both corners - no way to get them apart. Fortunately that was only 2 boxes that time:doh:


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## Alex Cantacuzene (May 29, 2003)

I have used half-blind dovetail joints and MitrLok for some time now and like both but much prefer the MitrLok. Set-up for both is a bit tricky but overall time is faster and much more reliable than finger joints, at least that is what I found. It all started with 3/4 free hardwood plywood that was being thrown out. We now have several boxes of that made from that plywood and they are standing up very well. On plywood we also forego the routed hand-holds and use cleats. For MitrLok joints we cut the lumber to the exact exterior lengths and widths and so have less material loss. Finger boards on the router table are a must. I doubt that we will use anything else but MitrLoks in the future. Very little clamping and they fit together easily without jigs. Just a satisfied customer with no connection to the manufacturer of these router bits. Take care and have fun


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## HVH (Feb 20, 2008)

If I ran many Locking miters, I would be tempted to set it up on the shaper with a power feed. The power feed holds the wood flat, so warped lumber would still end up with a good joint. 
I like the finger joints because of their strength but more importantly the boxes I purchase are cheaper than I can make and already have the joints. I might be able to save a little money by hand crafting but the opportunity cost is way too high. The time spent milling lumber is more useful to me elsewhere. Since everyone's needs are different I can see why some might want to spend a weekend in the garage for fun. I would rather assemble a hundred prefabricated boxes in a weekend than build 10 custom boxes. In years past, I made some boxes with finger joints and enjoyed the process. These days I am actually trying to make some money, so time must be managed differently.


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## Ishi (Sep 27, 2005)

Another important point in making Locking miters is to have the boards all the same thickness. If they are not they will never line up to a square outside corner.


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## PeeVee (Dec 10, 2009)

Very true! I buy rough cut locally, let it season and plane to 7/8. Pine for the mediums as it is light. I have been thinking of Eastern Hemlock for deeps as these would be moved seldom so th extra weight wouldn't be a factor.


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## PeeVee (Dec 10, 2009)

HVH,

Important point as managing time vs. money. This is currently a hobby for me, and having previously been a contractor, I know the value of time spent. If I ever get to the point of needing to turn a profit, I could not make the furniture as cheaply as I could buy ready made.


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