Joining vertical slats to horizontal pieces

[Chris Gilde]

Building my first major project:  an Arts and Crafts style desk.  I have two questions for anyone who can offer advice:

For the side legs system I plan to use vertical slats joined to upper and lower horizontal pieces (as illustrated) using pocket holes and then using filler plugs.  Wood material is all hemlock. Slat widths are 2.5" joined to 3/4" inch material.  

Since I have never done a project at this level before, any advice for clamping, gluing, and screwing?  

Is 2.5" width stock too narrow for two pocket holes on each end? Would it be best to join the vertical slats to the upper and lower horizontal pieces first and then join to the legs?

Finally, what's the best way to match hemlock material to available wood plugs?  I plan to use a a lighter stain finish.

Thanks; I'd be lost without this forum!

Chris

 

[Gary roofner]

You could also use biscuit joints but they are about the same strength as pocket holes but are invisible. I used them on my planter chair on the top rail slats and pocket holes in the bottom.

[Jay Boutwell]

For those who do not know how to cut a mortise and tendon.

Several days ago the topic of mortise and tendon came up is a discussion about joinery.  It was a discussion by member Chris Gilde.

 and was about the methods of joining vertical slats to horizontal pieces.  In this discussion I gave my opinion and suggested the use of 

mortise and tendon as the option I would use.  Since there was a comment that indicated that the method of how to do a mortise and tendon

was  not understood I am doing this post to help those whom do not fully understand the steps in cutting a mortise and tendon.

 

It can be done several ways using several different tools to cut the mortise and tendon however I will show the easy method using common tools.

 

For the mortise you will need the following:

 

A drill., with a brad point drill bit that is the width of the mortise you want to make.  You will need a small square to lay out the mortise and a pencil to mark the lay out lines.  A small wood chisel to cut the waste out of the mortise.  A hammer but the hand and palm pushing method on a sharp chisel is the most accurate.

 

For the tendon You will need only the addition of a hand saw and a rasp.  A vise or secure method of holding the stock.

 

Method of cutting:  I prefer to cut the mortise and then the tendon to fit the mortise.  It is easier to and more accurate to cut them in this order as you have a mortise that is like a pocket that you can use to fit the tendon into.  Determine the depth of the mortise and lay out the tendon length to that length minus about an 1/8 inch for glue. 

First cut the sides of the tendon using a saw down the lines made on the layout.  Be careful not to cut past the depth or the layout lines. 

Keep the saw square to the lay out lines.

 

 Saw the tendon shoulders square.  Using either a chisel or a rasp remove the excess wood until the tendon will  slide into the mortise without force yet still be tight enough to hold it weight when turned over in a position  that the tendon would fall out .

 

The attached drawing will explain how to cut a simple mortise and tendon.  The tendon should be cut so that it is a smooth slip joint that slides in with out a lot of force but still snug  and have room for the glue.

Anyone needing more help or have questions, feel free to contact me.

[Rita B.]

Alright Jay,  I am crying uncle and you can quit twisting my arm!  Hahaa!    I am going to try to attempt a mortise and tendon joint with some scraps using the method you describe.   I will probably start with some scrap soft pine since it would most likely be easier to cut and chisel.   However,  for this particular type of joint, is it suitable for all woods or is it primarily used for hardwoods?

[David Dean]

Here's a little trick I learn from a menber on here.If you can drill your hole's above and below your vertical slats.

[Jay Boutwell]

Well Hello Rita,I will release the pressure on the arm as long as you are going to try to learn the mortise and tendon.  I'm glad you were easy to persuade as I was getting tired of twisting your arm.  Haha   You will find that it is really easy to do and that it will be one of the most useful joints for building furniture.  Although the pocket screw is tough and strong joint, there are times when it is better to use the mortise and tendon.

To answer you question about the use of it in the type of wood.  It is good for soft wood as well as the hardwoods.  Actually in the soft wood the joint will be the strongest method.  Since you like building furniture, you will find this joint very useful especially when building furniture such as Mission style as its the most common joint used.
When I get time I will put together a better demonstration for this mortis and tendon.  I will try to do this soon.

If you have troubles with cutting the joint please twist my arm and I will respond with answers.

Your table that you posted sure turned out well and it very eye stunning.  It looks well built and I like the design.  I appreciated seeing the final results.

Alright Jay,  I am crying uncle and you can quit twisting my arm!  Hahaa!    I am going to try to attempt a mortise and tendon joint with some scraps using the method you describe.   I will probably start with some scrap soft pine since it would most likely be easier to cut and chisel.   However,  for this particular type of joint, is it suitable for all woods or is it primarily used for hardwoods?

[Ken Darga]

Additioinal info:

The illustration above, describes a basic mortise and tenon joint.

Although, there are many joint variations.

Generally the size of the mortise and tenon is related to the thickness of the timbers.

It is considered good practice to proportion the tenon as one third the thickness of the rail, or as close to this as is practical.

The haunch, the cut-away part of a sash corner joint that prevents the tenon coming loose, is one third the length of the tenon and one sixth of the width of the tenon in its depth. The remaining two-thirds of the rail, the tenon shoulders, help to counteract lateral forces that might tweak the tenon from the mortise, contributing to its strength. These also serve to hide imperfections in the opening of the mortise.

[Chris Gilde]

David:

This is actually a perfect solution for me since I can cover the pocket holes above the vertical slats with the drawer frame assembly and the holes below the slats with the bottom shelf assembly.  Also, a picture is worth a thousand words.  Thanks again!

David Dean said:

Here's a little trick I learn from a menber on here.If you can drill your hole's above and below your vertical slats.

[Rita B.]

Thanks Jay,  hope to get started with a practice piece this weekend.  I have a refinishing project going on right now that is keeping me from creating dust.

Ken, thanks so much for the photo.   Seeing it illustrated in such a way gives me a greater understanding of how I will need to lay out the markings for the cut with a much better overall idea of how the two pieces should fit together.

 

Mr. Dean,  great photo but I thought each board needed at least two screws at each end to prevent the board from twisting?

[Jay Boutwell]

Hi Rita, here is a more detailed explanation that I promised to do about hand cutting a mortise and tendon.  It is in a slide show so allow it a moment to load. 

http://www.smilebox.com/playBlog/4d7a63314d54517a4f44593d0d0a&b...
 
Rita Baske said:

Thanks Jay,  hope to get started with a practice piece this weekend.  I have a refinishing project going on right now that is keeping me from creating dust.

Ken, thanks so much for the photo.   Seeing it illustrated in such a way gives me a greater understanding of how I will need to lay out the markings for the cut with a much better overall idea of how the two pieces should fit together.

 

Mr. Dean,  great photo but I thought each board needed at least two screws at each end to prevent the board from twisting?

[james wilhelm]

Jay , very nice video on cutting a mortise and tendon , thanks for sharing with the community , JIM !!!

[Jay Boutwell]

If I was going to attach vertical slats to horizontal members such as found in a lot of mission style furniture including large item such as bed head board that is how I do it if I was not going to do an individual mortise and tendon in each slat.  It is simple and they will not turn and don't even have to have glue although I would elect to put some glue in to be sure they did not move or rattle when in use. It is fast and accurate way to do requiring only a dado in the center of the upper and lower support rails.  After cutting the rail dados I would then size the vertical slats to fit and then some spaces that is the same size and height as the dado is deep.  Easier method is to cut a long piece to fit and then cut to fit tight between each slat.  refer to photos:

My preference then is to mortise and tendon the top and bottom rail to their respective posts, however it can be attached very simply using pocket screw technology.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Jay Boutwell]

Thanks Jim, I hope it will be of use to some.  It is a hard subject to explain.

 
james wilhelm said:

Jay , very nice video on cutting a mortise and tendon , thanks for sharing with the community , JIM !!!