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How reinforce box miter joint?

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Forum topic by fazhou posted 08-14-2017 04:20 PM 564 views 0 times favorited 11 replies Add to Favorites Watch
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fazhou

11 posts in 1432 days


08-14-2017 04:20 PM

Topic tags/keywords: question

Hello all,
I was hoping to get some opinions or suggestions about reinforcing a box miter joint. I am making a shadow box display for a retiring military service member. The box will be walnut, 2 1/2”x 12”x 16” (approx). 11/16 inch stock. I no longer have a biscuit jointer, which would be my preferred option. I can do splines in the miter but would prefer not to. My idea is to make the miters very well fit, glue size the endgrain and then glue the box together usiing a band clamp. I’m thinking about running a dowel through the edgegrain, in the center of the miter, starting at the back of the box and obviously not coming through the face edge on the other side. Does that make sense? Maybe using epoxy to glue the dowel. I know that as far as miters go a box miter is not as susceptible to wood movement as a frame miter and the shadow box will see little if any stress. Thoughts? Opinions? Suggestions?


11 replies so far

View Loren's profile

Loren

9639 posts in 3488 days


#1 posted 08-14-2017 04:38 PM

I don’t think it will add any appreciable
strength to use a dowel that way.

If you have a drill press you can tilt
the table to 45 degrees and drill dowel
holes with a brad point bit. Be warned
this could be pretty easy to screw up
as the holes have to be dead on.

View AlaskaGuy's profile

AlaskaGuy

3662 posts in 2149 days


#2 posted 08-14-2017 05:01 PM

Some time it’s wise to do what you don’t want to do. I’ make a blind miter spline and be done with it.

-- Alaskan's for Global warming!

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Rich

1987 posts in 429 days


#3 posted 08-14-2017 05:04 PM

What’s the box going to be used for? I assume it’ll have a floor. That adds strength since it prevents racking that could break a joint. Given the thickness of the material I don’t see reinforcement being necessary, unless it’s going to be under significant stress. It sounds like you’ve got the end grain glueing technique figured out, so you should be all set.

-- No matter how much you push the envelope, it'll still be stationery.

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AlaskaGuy

3662 posts in 2149 days


#4 posted 08-14-2017 05:09 PM



What s the box going to be used for? I assume it ll have a floor. That adds strength since it prevents racking that could break a joint. Given the thickness of the material I don t see reinforcement being necessary, unless it s going to be under significant stress. It sounds like you ve got the end grain glueing technique figured out, so you should be all set.

- RichTaylor

I am making a shadow box display for a retiring military service member.

-- Alaskan's for Global warming!

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Rich

1987 posts in 429 days


#5 posted 08-14-2017 05:23 PM

I am making a shadow box display for a retiring military service member.

- AlaskaGuy

I’ve been making a few valet trays to give away as gifts, and using splined miter joints (the ones that go across the joint for strength and decoration). The stock is 1/2” thick, and I’m amazed at how strong the joints are, even before putting in the splines. I haven’t gone so far as to break one on purpose, but I’m confident they would be plenty strong on their own, particularly with a bottom glued in to prevent any sort of racking. Maybe if someone stacked some bricks in there and tried to pick it up by just grabbing one side it might crack — no, it’d definitely crack…lol. Maybe I should include a warning not to do that :)

Edit: I’m not saying don’t use splines or biscuits, just that if the OP doesn’t want to mess with them, it shouldn’t be a problem for a small box with thick walls like that.

-- No matter how much you push the envelope, it'll still be stationery.

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Rick_M

10645 posts in 2220 days


#6 posted 08-14-2017 05:32 PM

I agree, reinforcement is probably unnecessary unless he will be rough handling the box. The only thing would be if it fell off the wall, miters alone might come apart. Personally I like corner splines, they are easy and decorative.

-- http://thewoodknack.blogspot.com/

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AlaskaGuy

3662 posts in 2149 days


#7 posted 08-14-2017 05:54 PM

I am making a shadow box display for a retiring military service member.

- AlaskaGuy

I ve been making a few valet trays to give away as gifts, and using splined miter joints (the ones that go across the joint for strength and decoration). The stock is 1/2” thick, and I m amazed at how strong the joints are, even before putting in the splines. I haven t gone so far as to break one on purpose, but I m confident they would be plenty strong on their own, particularly with a bottom glued in to prevent any sort of racking. Maybe if someone stacked some bricks in there and tried to pick it up by just grabbing one side it might crack — no, it d definitely crack…lol. Maybe I should include a warning not to do that :)

Edit: I m not saying don t use splines or biscuits, just that if the OP doesn t want to mess with them, it shouldn t be a problem for a small box with thick walls like that.

- RichTaylor


I’m not sure why you’re telling me all that. I gave the OP my opinion. Maybe my bad but when he said he didn’t want splines I thought he might be objecting to seeing the ends of splines. So I suggested blind splines. A well fitting spline will go a long way it aliening the joint and holding in place during the clamping process.

Edit to add. If he’s thinking of the doweling I think the spline would be better and easier. But that’s just me.

- AlaskaGuy

-- Alaskan's for Global warming!

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Rich

1987 posts in 429 days


#8 posted 08-14-2017 05:56 PM



I agree, reinforcement is probably unnecessary unless he will be rough handling the box. The only thing would be if it fell off the wall, miters alone might come apart. Personally I like corner splines, they are easy and decorative.

- Rick M

Corner splines. That’s the term I was trying to think of. Thanks, Rick.

-- No matter how much you push the envelope, it'll still be stationery.

View fazhou's profile

fazhou

11 posts in 1432 days


#9 posted 08-14-2017 07:32 PM

Thanks for the replies. The back (bottom) will not be glued in but screwed in place. In a rabbett of course. So the dowel idea is not dowels in the endgrain, but rather, after the box is glued up, drill a hole in the edge, centered on the miter from the back and then a dowel glued in the hole. The epoxy bit is very relevant in this case. It would be like a spline but much easier. I’m not sure how I would cut a blind spline in something so narrow. And if I did do a blind spline, it would have to be rounded to accommodate a table saw kerf, correct?

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Rich

1987 posts in 429 days


#10 posted 08-14-2017 08:26 PM


I m not sure why you re telling me all that. I gave the OP my opinion.

- AlaskaGuy

Well, AG, if you go back to post #3, I asked the OP what the box would be used for. It matters, you know. For some reason you must have thought I was asking you about your post #2, even though I didn’t quote it. Just because a post comes after yours, doesn’t mean it’s in reference to yours.

I figured maybe you were feeling lonely, so I quoted your post about the shadow box in my reply, which I intended to provide anecdotal evidence to support my “no spline” suggestion as a viable option for the OP’s box.

-- No matter how much you push the envelope, it'll still be stationery.

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AlaskaGuy

3662 posts in 2149 days


#11 posted 08-14-2017 10:01 PM

I could be Confused, it happens often. In post 3 you ask ” What’s the box going to be used for?”

My post 4 was just pointing out the he has said in post 1 “I am making a shadow box display for a retiring military service member.”I thought maybe you had missed that base on your question in 3 “What’s the box going to be used for?”

Anyway my personal choice would be to enforce the joint if I were building.

I’m probably still confused. :)

-- Alaskan's for Global warming!

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