# Need Help With M/T Joint Cutting and Shaping



## Wood4Brains (Jul 25, 2012)

Hi there, Everyone:

I am trying to put a vertical 2 X 2 into a couple of boards - the top one a piece of a 2 X 3 Doug Fir, the bottom a 1 X 12 pine board. It is kind of hard to explain, but this is a dry fit to kind of give you an idea:










I am having a bear of a time trying to cut the mortise for these. I have narrowed the problem down to two small issues:

1) I probably don't have the right tools, and

2) I have no idea what I am doing 

This is what the cuts looked like before the dry fit:










So my questions are:

1) What kind of tools do I need to make a decent mortise like this? 

I used a 1-1/2 Spade Bit in my electric drill, then used my "four way rasp / file" to expand the hole. As you can see, they are both very sloppy :thumbdown:

2) Any suggestions on proper technique for this?

Because the tenon (the post) is going to be sticking out the other end and will be visible, I can't really cut the tenon to fit the mortise because the end will look all funky.

My tool list now includes:

Circ saw,
Electric Drill
lots of misc files
Some small chisels (hopefully arriving today)
1 HP Fixed Base Router, 1/4 inch shanks (bits arriving soon).

thanks in advance for any suggestions.


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## rayking49 (Nov 6, 2011)

After drilling the holes you can use a sharp chisel to square u the corners of the mortise.


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## Wood4Brains (Jul 25, 2012)

Thanks, raykling.



> After drilling the holes you can use a sharp chisel to square u the corners of the mortise.


as it just so happens, there are a couple of chisels in a box that just arrived by mail that I am dying to test out.

One more thing: The post I am putting in has radial corners. Is there any secret to making the corners of the mortise curved?

thanks again.


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## Wood4Brains (Jul 25, 2012)

Oh, and one more thing...

would it have been better to affix the small piece of doug fir atop the pine 1 X 12 FIRST before trying to drill / mortise them?

I think I did the pine board first, and then put the hole on top of the doug fir as a template and just used a pencil to draw a line around the edge of the mortise.

Thanks in advance.


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## rayking49 (Nov 6, 2011)

You can lay out the mortise by measuring and drawing with a ruler, or using a template like you did. The radiused corners come naturally with a router bit. Or you can try to square up the tenon going into the mortise. It should fit into the mortise snugly, by hand. You should not have to beat it in, in other words. But not too loose either. A good snug fit with glue gives it alot of strength. If the radius on the corners is not real big I wouldn't worry about it, It will let excess glue come out..


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## Steve Neul (Sep 2, 2011)

Instead of using a 1 1/2" drill bit which leaves too big of a radius at the corner I would use a 3/8" drill bit and drill 4 holes on the corners, with a drill press if you have one. Then cut between the holes with a jig saw. Also if you plan to use this to hang a bunch of weight like in the last thread I would put the hole farther from the end of the board. A lot of weight can tear the end of board out.


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## woodnthings (Jan 24, 2009)

*This is a nice "sample" joint, but....*

Without knowing the application, and force directions, loads etc...it's difficult to say how strong it will be and if another type of joint may be a better solution. If you are just practicing making a square hole for future projects, then that's fine. the problem is where the hole/mortise is located on the stock. It's to close to the end which will split out if any lateral force is applied...like a lever on the vertical piece. Both ":A" and "B" are the problem areas. Pine is especially prone to splitting along the straight grain close to the ends of the stock, so be aware in future applications.


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## Wood4Brains (Jul 25, 2012)

Thanks again guys!!! :smile: :smile: :smile:

*@ Steve Neul*



> Instead of using a 1 1/2" drill bit which leaves too big of a radius at the corner I would use a 3/8" drill bit and drill 4 holes on the corners, with a drill press if you have one. Then cut between the holes with a jig saw.


Thanks so much! I misspoke, it is actually a 1-3/8 drill bit (not 1-1/2) but your suggestion about drilling the four corners and then using the jigsaw is MUCH appreciated. Thanks again for mentioning that.

*@ woodnthings*



> the problem is where the hole/mortise is located on the stock. It's to close to the end which will split out if any lateral force is applied...like a lever on the vertical piece. Both ":A" and "B" are the problem areas.


thanks for pointing that out. It is one of those things that seems obvious once someone tells you :blink:

I don't know if this is going to change anything, but...

For the 1 X 12 pine board I am actually going to laminate (I think that is the right word) on top of another 1 X 12 pine board. Basically, what I am trying to accomplish is something like this:










I have not idea how they did the joints where the vertical joins the base.

To me the base looks like 2X stock and the vertical post is nearly flush with the back (it might be completely flush)

My thought was 

- place two 1X pine boards on top of one another.
- Through mortise on the top board
- Put a 2 X 3 "collar" with a through mortise on top of the top pine board, then glue and screw it to the top pine board for strength.
- use a lag bolt from the underside of the BOTTOM pine board up through the end of the vertical 2 X 2 post.

and of course, lots of glue.

I know that in the photo above they used a different kind of joint, but I can't seem to find a vertical post as thick as the one they are using. I think they are using an ACTUAL 2 X 2 while I can only get a nominal 2 X 2 (actual 1-1/2 X 1-1/2)

So I am trying to figure some way to get the same strength while using slightly smaller stock.

Alas, if I had a table saw I could have ripped some bigger stock to the right size... I am not nearly competent enough with my circular saw to attempt that though.

Thanks again.


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## firemedic (Dec 26, 2010)

Ahhh, now we see what you are building. You want a wedged tenon for that. 

The other option, given the nature of it would be KD bolts... That would require a bit of tooling up for you though so wedged tenons would be the way to go.

Either way, Bill already pointed out the need for a stronger mortice. Move the mortice in a bit from the edge but also turn the board 90 degrees so the long grain is on the thin side. You also want to have a shoulder on the tenon to keep it square and prevent sagging. 

I sketch it if you don't follow what I mean.


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## Wood4Brains (Jul 25, 2012)

Thanks so much for the input, Jean!



> Move the mortice in a bit from the edge but also turn the board 90 degrees so the long grain is on the thin side.


I think you mean that you would turn Board B (in woodnthings photo) so that the majority of stress (front to back) will run across the grain instead of with the grain? 

Or do you mean for piece A? (Or BOTH pieces, A AND B?)



> You want a wedged tenon for that.


would that be for the base and the vertical post?

I can see how it would work for the "flag" (the short piece that sticks out horizontally from the vertical post), but not for the post to the base, so maybe it was the flag you were referring to?



> You also want to have a shoulder on the tenon to keep it square and prevent sagging.


Hmmm... I think I see what you are saying.

I don't know if this is going to help, but that pine 1 X 12 board (labeled B in woodn'things's photo) is going to be glued and screwed face-to-face on top of another pine 1 X 12. that bottom 1 X 12 WON'T have a mortice cut in it.










A is glued on top of B
B is glued on top of C

A and B have a Mortise, C doesn't (just a pilot hole)

Vertical piece D will pass through mortise in A and B

Bottom end of Piece D will glue to top face of Piece C

Copious amounts of glue (or should I use epoxy???) will be applied.

Thanks in advance for any suggestions. If you think I should start over, then just let me know. I am not too proud to accept suggestions!


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## woodbutcher360 (Jul 1, 2012)

I could be wrong, but I don't see a shoulder on the vertical piece. A shoulder would greatly add to the stability of the joint. 
Google wedged tenons. You will see a through tenon with a narrow slot cut into it. Then a wedge is driven into the slot. Cut the wedge off flush with the flat piece.
Rather then use the short piece of wood I would opt for 3 right angle bracing at the bottom of post. (glued and screwed)

As far as a lag bolt, you're going into endgrain of the post, not the best solution.


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## woodbutcher360 (Jul 1, 2012)

Here you go. Try this page, it should answer a lot of your questions and give you some insight. Hope it helps
http://woodworking.about.com/od/joints/p/MortiseTenon.htm


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## firemedic (Dec 26, 2010)

Yes, piece B. that will strengthen the mortice.

I misunderstood the design. Is the upright going to just slip in and not have a rigid connection? I was referring to the wedged tenon being where the upright connects to the base.

As for the "flag" section that would be better served by a bridle joint I believe.


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## Wood4Brains (Jul 25, 2012)

> I could be wrong, but I don't see a shoulder on the vertical piece.


You are correct, sir. Yes, it has no shoulder.

I thought that having a shoulder in this instance would increase the area that end grain joins face grain (of Piece C) at the cost of reducing the area of face grain (of Piece D) that connects with the inner walls of the mortise (of parts A and B).

And thanks for the link to the tenon explanation page. I found a good site on how to make a wedged tenon:

http://americanwoodworker.com/blogs/techniques/archive/2009/09/08/wedged-mortise-amp-tenon.aspx

Of course, after_* looking*_ at how to do it, I needed to take a couple of aspirin (and a Xanax or two) and lie down. My brain was all like, "Oh, No You don't!" Making a wedge joint is going to be a BIT of a challenge.



> Is the upright going to just slip in and not have a rigid connection?


I am not 100% sure what you mean by rigid in this case. I want to AVOID bracing, if that's what you mean by rigid.

I hope to glue it in to the mortise and use the lag bolt / wood screw for rigidity. I was hoping that would be enough?!?!?!

I thought (hoped) that having the 2 X 3 collar (Piece A) glued to the surface of the top pine board (Piece B) all that surface area for the glue with the mortise in parts A and B would make it rigid.

Am I living on Fantasy Island again? :boat:

P.S: If this works, I take full credit for it. And if it doesn't work, well, it was all cabinetman's idea... :no:


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## woodnthings (Jan 24, 2009)

*another manner of mortises*

You can make a mortise by leaving a gap in 3 layers of wood glued together, or a rabbet. Look closely and you will see the top, middle and bottom pieces and a gap in between forming a rectangular mortise. You can stack pieces to form a mortise vertically as well, just leave a gap for the size piece you want to fit in between....:


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## Wood4Brains (Jul 25, 2012)

*@ firemedic*



> The other option, given the nature of it would be KD bolts...


When you say KD Bolts, do you mean these things?











Otherwise, I couldn't find anything else called KD bolts.

I found the KD fastner company website, but they seem to have LOTS of different fasteners.

thanks in advance.


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## Dave Paine (May 30, 2012)

KD is "Knock Down" aka flat pack furniture.

Lee Valley has a few of these fittings. Providing a link, although this may not be the best solution for your needs.

http://www.leevalley.com/US/hardware/page.aspx?p=40049&cat=3,43715,43716&ap=1


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## firemedic (Dec 26, 2010)

*Bed Bolts*



Wood4Brains said:


> *@ firemedic*
> 
> 
> 
> ...





Dave Paine said:


> KD is "Knock Down" aka flat pack furniture.
> 
> Lee Valley has a few of these fittings. Providing a link, although this may not be the best solution for your needs.
> 
> http://www.leevalley.com/US/hardware/page.aspx?p=40049&cat=3,43715,43716&ap=1


WOW, LV's KD bolts are pricey!

I guess KD was the wrong term to use, I was more thinking along the line of bed bolts, but a regular bolt and nut could be made to work. The problem with the lag bolt is that, as was already said here, it won't hold in end grain. It won't take long for it to loosen up and pull out. Are you familiar with bed bolts?

All the "four-way" and "ballet bar" displays I've assembled lately (quite a few at that) have been metal. With a similar design. The bolt is welded inside pipe or square tubing though. With a bed bolt is would allow you to compress the end grain and utilize all of it's strength.


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## Wood4Brains (Jul 25, 2012)

Thanks for the help, everyone, and Jean, thanks so much for the photo of the bed bolts.

One question: in the top photo (the lighter colored one), it appears that they are also using dowels along with the bed bolt. Are they just using them to prevent the pieces from rotating? (since there is just a s single axis)

Since I will have a mortise that the riser fits into, can I avoid having to use dowels?

A friend suggested that I would be doing myself a favor by using a brace, which I would put in the FRONT of the riser (since the cantilever force would be on the front), and I am wondering if I could cut the slot for the nut in the front of the riser too, so that when I put the L brace up, it will "hide" the slot for the nut?

Also, I am assuming they are called "bed bolts" because they are used for assembling beds? I hope so because I have a bed I need to fix...


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## Greg in Maryland (Jan 6, 2011)

Yes, the dowels are there to prevent twisting. I would expect that if parts A, B and C in your diagram are assembled as you present them, then twisting would be kept at a minimum. It would not hurt to add dowles.

I have never purchased bedbolts for this type of application, I just go to Home Depot or Lowes and purchase lag bolts, washers and nuts. This route should be more inexpensive and convenient.

Is the back of your apparel racks visible or will it be against a wall or otherwise obscured? To use drawbolts, you have to drill two holes -- one from the bottom of part D and the other from the side or back of part D. It does not have to go all the way through, just enough to engage the nut. You will have to enlarge and square up the hole so that the washer and nut have a flat place to lie. 

I would not be tempted to plug any resulting hole with a dowel. If you do this, you lose the ability to tighten the joint if it works loose.

Just a few words of caution, you want to make sure that your cross hole isn't too big that it weakens the post. Also, if you are thinking of using lag bolts and calling it a day, eventually they will fail. End grain does not hold all that well. Especially since there will be wracking forces on the assembly.

Good luck!


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## Wood4Brains (Jul 25, 2012)

@ Greg In Maryland:

Thanks so much fro the advice!!!



> I have never purchased bedbolts for this type of application, I just go to Home Depot or Lowes and purchase lag bolts, washers and nuts. This route should be more inexpensive and convenient.


yeah, that was my first instinct - mostly because I am cheap and lazy. 

But as you rightly pointed out:



> Also, if you are thinking of using lag bolts and calling it a day, eventually they will fail.


firemedic (aka, Jean) had mentioned that too, so I thought I would try to go the extra mile and give the bed bolts solution a try.

Also, I do have a bed I have to fix up eventually, so this will be good practice in seeing IF I can transfer this to other projects given my limited skills and tools.



> ...you want to make sure that your cross hole isn't too big that it weakens the post...


Thanks for the reminder.

is there any rule of thumb as to how big of a hole I can chisel out?

Also, while the back will be against a wall, I am thinking of putting the access hole IN THE FRONT because I also plan on using something of an L Brace to help keep the riser in place. I thought that I could use the L Brace to "hide" the hole (since the L Brace will be in front).

Only thing is, if I have to screw the L Brace flush to the face of the riser I don't know if the screw will clear the Bed Bolt.

I kind of think it won't...


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## Greg in Maryland (Jan 6, 2011)

Stop! I didn't mean lag bolts, I meant hex bolts. Big difference

Greg


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## Wood4Brains (Jul 25, 2012)

Hi again, Greg:



> Stop! I didn't mean lag bolts, I meant hex bolts. Big difference


Could you explain a little bit about the differences? (especially in regards to what I am trying to accomplish).


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## Greg in Maryland (Jan 6, 2011)

Lag bolts are glorified wood screws. Check this link at Home Depot. They have course threads and are not used with nuts.

Hex bolts are similar size, but are designed to be used with nuts. Check this link at Home Depot.

Hex bolts can be used in place of bed bolts in your specific situation without any problem. I cannot comment on their suitability for beds.

The reason hex bolts are ideal for your application is that they can be tightened and tightened and tightened, and won't really damage the pieces or really enlarge the holes. Presuming that you use washers and don't compromise the strength of the wood by making too big of a hole too close to the edge or something like that.

Lag bolts will eventually work themselves loose and degrade the hole they are drilled into. Once the hole gets too enlarged, you are unable to tighten it. This is if you try to use a lag bolt to hold in end grain.

Hopefully this helps and isn't too inaccurate 

Greg


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## Wood4Brains (Jul 25, 2012)

Thanks so much for the links and the clarification, Greg!


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