Building a small through tenon shelf for a DVD player

[Andrew Pitonyak]

I wanted a small free standing shelf for me to put a DVD player along with a few remotes. I decided that I would use through tenons to secure the two shelves into the sides. Never having done this before, I was not really sure where to start so I decided to punch a few holes into the sides first and then try to cut the tenons to match the sides.

QUESTION: Opinions on how I should have done this?

While cutting the holes, I was having trouble making sure that I was cutting square. My squares were all too large. I ended up using a piece of scrap and then I cut each hole so that the tenon on the scrap would go through; probably a good idea anyway. For certain my sides are not square, so, the hidden side has a slightly larger hole than the visible side. This is where I asked which square to buy:

https://sawmillcreek.org/showthread....08#post2896708

I was not really sure how to mark the shelves so that I would know where to cut my tenons. My tenons were two wide enough in one dimension so that I was able to get a smaller square into it. I clamped a side and a shelf in my Moxon vise to that I could use my square to mark where to cut the tenons. I thought it was clever, but, I don't think that I could have simply held the shelf in place and marked it accurately enough. Might have been easier if I had cut the tenons first (from a marking perspective). Opinions?

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After that it was similar to cutting my dovetails:

Cut straight down with my dovetail saw.
Use a saw to cut out the waste in the middle.
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Finally cut from the side to remove the last of the waste. I have not used my cross cut saw in a very long time, it worked great, but it left a rougher edge than my dovetail saw.

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I cut the tenons just a wee bit longer than the thickness of the material so that it would stick out just a bit. I then put a chamfer along the tenons.

This is a dry fit before any sanding.

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I thought that it looked a bit blocky, so, I cut some legs into the sides and I rounded the front. This is a side shot.
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I was playing around a dye and I did not care for the color, so I tried something that I really disliked..... So I slapped some cherry gel stain onto it and it hid all the stuff I did not like. Not really what I wanted to do, but it was fast and it will be fine where I put it at church.

So really my first mortise and tenon project.

[John Isgren]

I think you are fine since the DVD players are so light, but you might have wanted to put in small housing dadoes for the shelves to sit in. In your case all of the weight is on the narrow tendons. If you cut the dado and then the tendons you could put the tendons in the grooves and then mark the edges of the through mortises.

Like I said though, it looks nice and is fit for the purpose.

[Warren Mickley]

I think your tenon lay out was very sloppy. You want to lay out the mortises on both sides of the board and work the mortises from both sides. You don't need to put a square through the mortise at all for this work.

Lay out everything from the front edges of the pieces (the face edges). For example, if the tenons are two inches from the front edge, set a panel or marking gauge at two inches, then make 16 marks with it without changing the setting: two on the left out side, two on the left inside, likewise four on the right side, two on the top side of the upper shelf two on the bottom side of the upper shelf. Then set the gauge at 3 1/2 inches and do another round of 16. 64 precision lines on the work should not take five minutes, and they all match.

For horizontal mortise markings, put the two sides together in the vise, front side up. Mark the upper and lower bounds of each shelf on the front of the sides. (They will match because you are marking them together.) Then using a knife and a square mark the sides all the way around. Likewise for the tenons, put the shelves in the vise together for marking the front edge so their distance between tenons match.

You could do this whole project, precision joinery without the use of a measuring device.

[Andrew Pitonyak]

I think you are fine since the DVD players are so light, but you might have wanted to put in small housing dadoes for the shelves to sit in. In your case all of the weight is on the narrow tendons. If you cut the dado and then the tendons you could put the tendons in the grooves and then mark the edges of the through mortises.

Like I said though, it looks nice and is fit for the purpose.

I considered cutting a long dado to hold the shelf, I have done that in the past using a router or dado blade.

[Andrew Pitonyak]

Thanks Warren, I really appreciate the advise.

[Robert Engel]

I think Warren hit the nail on the head.

It really is an exercise in marking accuracy.

I like to put a slight rabbet on both sides of the shelf. This gives me an out in case there is a little gap and gives a cleaner look.

Alternatively a shallow dado can be made in the side. This also serves the purpose of defining the upper and lower walls of the mortise.

I also always used wedges in thru tenons. This not only strenghtens the joint, it will draw the side tight to the rabbet in the shelf.

[Matthew Hartlin]

Becksvoort has a Shaker Stool plan in Finewoodworking that uses the same joinery with the addition of a shallow dado, which does a good job of explaining layout. Like others said, marking both faces of the mortise and working in from both sides is key. Wedging the joint also helps tighten up any discrepancies.