# How should I cut this box joint?



## Ron_J (Sep 22, 2014)

I'm getting ready to start on a 4'x2' chest that I'd like to use a box joint for the corners. I have done a few box joints, all on a jig for the table saw, but they were on much shorter pieces that 2', let alone 4'. I'm not sure how hard it will be to cut box joints in a 4'x 2' panel on a table saw. I thought about a router, but not sure about what kind of jig I would need.

If you were to cut joints for a box similar to this, how would you do it?


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## Terry Q (Jul 28, 2016)

You just want box joints at the corners, not on the bottom. If you use box joints on the corners as shown in the photo, you won’t have problems with wood movement, the box will grow and shrink in height with no problems. If you try to attach the bottom with box joints the board will be constrained by the sides and you will eventually blow out the bottom corners. Best to use a different method to attach the bottom.

As for bigger boards, 2 foot box joints aren’t any different then smaller boxes if you can cut them accurately. Basically, you are just scaling up the project. I’d use 1/2 inch or bigger box joints to make it easier. 


In woodworking there is always more then one way to accomplish something.


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## Toolman50 (Mar 22, 2015)

I agree with you that trying to cut a box joint on pieces that big on the tablesaw will be difficult. 
I think I would use the router. 
You will need t make a jig because a dovetail jig won’t be long enough. 
You might try to make a jig attached to your hand-held router that will index, using the last cut made for correct spacing. 
Others may have ideas they’ve used successfully.


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## Ron_J (Sep 22, 2014)

Toolman50 said:


> I agree with you that trying to cut a box joint on pieces that big on the tablesaw will be difficult.
> I think I would use the router.
> You will need t make a jig because a dovetail jig won’t be long enough.
> *You might try to make a jig attached to your hand-held router that will index, using the last cut made for correct spacing*.
> Others may have ideas they’ve used successfully.


This is what I was thinking, but a little unsure how to tackle it.


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## Ron_J (Sep 22, 2014)

Terry Q said:


> You just want box joints at the corners, not on the bottom. If you use box joints on the corners as shown in the photo, you won’t have problems with wood movement, the box will grow and shrink in height with no problems. If you try to attach the bottom with box joints the board will be constrained by the sides and you will eventually blow out the bottom corners. Best to use a different method to attach the bottom.
> 
> As for bigger boards, 2 foot box joints aren’t any different then smaller boxes if you can cut them accurately. Basically, you are just scaling up the project. I’d use 1/2 inch or bigger box joints to make it easier.
> 
> ...


I' was thinking about 3/4" joints, to match the thickness of the panels. My concern is the 4' board sticking up in the air as I try to run it thru the table saw.

I think I am going to have the bottom float in a groove in the sides.


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## mjadams61 (Jan 1, 2016)

I am not sure if this would help you but part of my DIY router table is going to be where I can do this. But all depends on what size table saw a full shop one or jobsite one but maybe you can adapt this box joint jig to work for you and a dado blade since your tablesaw has dual tracks already and you beable to make the jig large enough to clamp and support your large pieces.


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## WesTex (Jan 5, 2014)

I would just lay out my cuts with a sharp pencil and then cut the joints with my dovetail saw. 


Sent from my iPhone using Tapatalk


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## Steve Neul (Sep 2, 2011)

If it were me I would do it on a table saw. Use a miter gauge with a board screwed to it and put a pin on the board the width of the blade from the blade. From there you just put the wood against the pin and make your first cut with the part on it's end and then lift it over the pin and set the first dado on the pin and just keep going until you reach the end. Then the opposing part you make the first cut flush with the end and then use the same miter gauge with the same pin.


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## Terry Q (Jul 28, 2016)

On end with four feet sticking up is going to be hard regardless of whether you use a tablesaw or router table.

I’ve never done box joints on anything that wide, but if I was going to try I think I would try doing it on my table saw for the following reasons:

1) Taking 3/4 deep by 3/4 wide box joints is going to be really tough on your router bit. Generally, taking more then 1/8 -1/4 inch per pass is all that’s suggested.

2) I think you will need to use a sled that you can attach your board to so it won’t move when cutting it. To improve the chance of success, I’d try to use both miter tracks that are found on table saws. Router tables rarely have more then one.

3) using a dado blade will allow for very precise adjustments to width of cut to make slight adjustments to your fit. Router bits make fixed size cuts.

There are many videos showing the process of cutting and spacing for the next cut, I’d look for ideas that help dealing with large pieces of wood. Like I say, a sled with solid right angle support tall enough to clamp your board. It might be a pain, clamping and unclamping every cut, but maybe you won’t have too, but if you need to the option exists.

I’d also like to suggest that you cut both long pieces at the same time, saving time and clamping. It also assures that if you screw it up, you can just make your box a little smaller by cutting off the end and starting over. Actually, you should probably cut the first end on oversized boards just to test the fit with actual material. You can resize after first end is successfully cut.


In woodworking there is always more then one way to accomplish something.


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## woodnthings (Jan 24, 2009)

*here's a tip ... untried however*

I would use the table saw with the box jig, to make a pattern for the hand held router. I can't see standing a board of that length vertically on either the table saw or the router table, hence the hand held router. The pattern would be 24" long by about 3" wide and 3/4" thick. You would use a top mounted bearing bit in the notches so you don't tear it up. You would probably have to make several passes at increasing depths for a 3/4" notch. :vs_cool:


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## Toolman50 (Mar 22, 2015)

After thinking about this project some more, I think the best approach will be to make a sled with a tall back fence. Set you jig up on the sled and use the table saw with a dado blade. This sled will probably be used for this project only and can be made of plywood or MDF. 
The pieces can be clamped to the fence for each cut for accuracy.


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## Larry42 (Jan 10, 2014)

I would do similarly to what Terry suggested. Make your sled heavy and tall enough to support the parts well. Put some sort of clamping device on the sled to hold the parts against the fence during the cut. This assumes you have a decent table saw.


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## Jig_saw (May 17, 2015)

It looks like dovetail joints to me in that picture. I would cut it simply & easily with a dovetail saw, in the same time as it would require one to set up a cutting jig on a table saw or a router table. Here is a good video on cutting dovetail joint by hand:


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## Ron_J (Sep 22, 2014)

Steve Neul said:


> If it were me I would do it on a table saw. Use a miter gauge with a board screwed to it and put a pin on the board the width of the blade from the blade. From there you just put the wood against the pin and make your first cut with the part on it's end and then lift it over the pin and set the first dado on the pin and just keep going until you reach the end. Then the opposing part you make the first cut flush with the end and then use the same miter gauge with the same pin.


This is how I have done it in the past with good results. Like I said, just a little apprehensive about doing it with a 4' board.


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## Ron_J (Sep 22, 2014)

Toolman50 said:


> After thinking about this project some more, I think the best approach will be to make a sled with a tall back fence. Set you jig up on the sled and use the table saw with a dado blade. This sled will probably be used for this project only and can be made of plywood or MDF.
> The pieces can be clamped to the fence for each cut for accuracy.


I think this is going to be my approach. My TS sled is only 6" tall, but I can replace the back fence with a taller fence easily enough.


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## Ron_J (Sep 22, 2014)

Terry Q said:


> *I’d also like to suggest that you cut both long pieces at the same time, saving time and clamping.* It also assures that if you screw it up, you can just make your box a little smaller by cutting off the end and starting over. Actually, you should probably cut the first end on oversized boards just to test the fit with actual material. You can resize after first end is successfully cut.


I like this idea.


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## Steve Neul (Sep 2, 2011)

Ron_J said:


> This is how I have done it in the past with good results. Like I said, just a little apprehensive about doing it with a 4' board.


Yes it's a bit cumbersome but doable. The board you put on the miter gauge could be ten to twelve inches wide and you could even put some brackets on the back side to keep it from bending.


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## hawkeye10 (Feb 18, 2015)

Well Ron I also have an opinion. I have tried making box joints on a router table and the problem is tearout on the front side. Unless you put a board in front of your work piece you will have this problem.


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## Ron_J (Sep 22, 2014)

Just thought I would update this, in case anyone is looking to do the same. It ended up not being as bad as I expected. I added an extra high backet to my miter and clamped the piece for every cut.


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## TimPa (Jan 27, 2010)

nicely done Ron! 


I know where you could have got a leigh dovetail jig!! you did it a lot cheaper tho....




looking forward to the assembly pics!


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## Ron_J (Sep 22, 2014)

TimPa said:


> nicely done Ron!
> 
> 
> I know where you could have got a leigh dovetail jig!! you did it a lot cheaper tho....
> ...


Ha...You know someone that has one for sale? :grin:


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## Larry42 (Jan 10, 2014)

Looks good. That size panel must be difficult to control. 
Do those open extensions ever catch on floppy materials?


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## Ron_J (Sep 22, 2014)

It wasn't as bad as I was expecting. Once clamped to the backer board, even the 4' pieces were pretty solid. Solid enough that all the cuts are uniform.

I haven't had problems with the open extensions. The grid pieces are recessed a bit, so it would have to be a pretty "floppy" to catch. At least more than any piece of wood I would think you would cut.


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## FrankC (Aug 24, 2012)

Late to the party, there is a way to cut box joints on very long boards, if the inside of the corner is hidden such an apron for a table.

Reverse your miter gauge and make the standard back board and pin jig with the pin facing you, you will be raising the dado blade as high as possible so the end of the back board will be cut off.

The board lays flat on the saw and you push it through endways into the dado blade, fix a stop behind the miter gauge to make cuts of an even depth as you move the board from one notch to the next one. To keep the board straight the fence is moved tight to the board once the notch is on the pin.

The back of the cuts will be deeper due to the curvature of the blade but the front will fit like any other dado. If you wish you can hand finish the cuts deeper on the front for a tight joint.

This will also work for a chest that will be lined with cedar which will cover up the inside of the corner.


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