Tricks for hiding box bottom dadoes on through dovetails. (handtools only)

[DTBoss]

I've seen a number of methods for hiding the ends of dadoes used for box or drawer bottoms, but I'm wondering if anyone has 'tried them all' and arrived at a preferred solution. Stopped dadoes are easy with a power router (I'm told), and possible with a router plane and chisel (I've done it but it wasn't easy). I'm after a hand tool only approach. Many thanks.

Dan

 

[Hmerkle]

I am told - no expereince here... but many more smart people WILL chime in...

It is a bit of a pain, but I am told - to lay-out a "covering pin" where the dado will break out...

 

[Gofor]

Best way for a box of all equal thickness sides that I have found is to rabbet the inside ends of all sides to the depth of the bottom groove (dado), and to the width of the length of the tails and pins, using a rabbet plane. This means the thickness of the tails and pins will be less than the thickness of the sides. Example: For a box with 3/4" thick sides, I would rabbet the ends to 1/4" deep x 1/2" wide. The pins and tails will be 1/2" long and 1/2" thick (finished), and I have a 1/4" deep dado for the bottom to sit in. With this method, you don't have to be concerned about the location of the bottom dado when laying out the dovetails.

In practice, I use a saw to set the width of the dado before planing. Because I want the ends of the tails and pins slightly proud after glue up, i cut the sides a little long, and register the inside of the saw kerf to where I want the finished interior dimension to be. This means the rough dado would be wider than the 1/2" stated above. If I end up with too wide a dado (meaning my tails/pins would be too far proud after assembly), I plane back the end of the board to give me about 1/32" proud before I cut the dovetails. Because this is my method, I lay out my sides based on the inside dimension. (Hope this makes sense to you)

I have also done stopped dados for the bottom. Rather than get overly concerned about the very end of the dado, I trim the corners of the bottom at 45 degrees to just clear the inside of the joint. With this method, there is a possibility that a very small gap at the corner would be visible when the bottom is dry and fully contracted if you use solid wood.

For a drawer, I use the same method for the front (unless I am going to put on a false front). which is thicker than the sides or back, and I don't worry about the back because not only will it not be seen, I want the bottom to be able to expand and contract under the bottom of the back (when using solid wood bottom). The dado runs in the center of the sides' pin slots (between the tails).

Hope this helps and doesn't confuse.

Go

 

[Hmerkle]

Mark,
I think I get it - but since your answer differs from the one I expected, a picture would be helpful...
(BTW - where is Richard (Greywolf) and Mike Davis' answers????)

 

[Dave Richards]

I think he means like this.

 

[danmart77]

The simple solution for me is keeping the dado above the pin line of the front. In the illustration in reply 2 you can see this clearly. I do pins first on a box and this is where I consider pin size to make things easier down the road. These drawers were graduated in size and the bottom turned out to be pretty deep.

I tend to keep the dado a little high so I don't get rubs.

Dado cuts were done in the poplar with a Stanley 45

​

This is something to be examined with an example.

Extended sides for adjusting a cockbeaded drawer.

cockbead front below-- no stops on the face

 

[Gofor]

Thank you Dave and Dan for good illustrations of what I was attempting to convey.

Go

 

[Charles Lent]

I use special small diameter bottom bearing slotting bits from Lee Valley. I dry assemble the 4 sides of the box and hold it together with a band clamp. Then I install one of these slotting bits in my router table and set the height of the bit for the position that I want the bottom of the box to be above the bottom edge of the box sides. Then I run the bottom edge of the box around the bit to cut the slot in all four sides of the box or drawer. If it's a drawer and I want to slide the bottom in, I later use my table saw to rip the back piece to remove the slot and bottom edge. These bits are small enough in diameter that they cut into the corners of the box, but not through to the outside. All that's needed is a slight rounding of the box bottom corners before installation, and the bottom will fit perfectly into the box corners without leaving a gap in the corners of the box. The bits come in three sizes for different thicknesses of box bottoms. Using these has been the fastest and easiest way that I've found to do this, and it's almost impossible to do it wrong.

http://www.leevalley.com/US/wood/page.aspx?cat=1,46168,46176&p=47818


Charley

 

[Mike Davis]

This is how I do it...

 

[Gofor]

I am going to vote for Mike's method, especially for hand tools. Now, if only I could saw to the line!

Go

 

[DTBoss]

This is how I do it...

This is very clean. I need to practice my 45* cuts too. Do happen to have a photo of your pins? Thanks Mike.

 

[DTBoss]

Best way for a box of all equal thickness sides that I have found is to rabbet the inside ends of all sides to the depth of the bottom groove (dado), and to the width of the length of the tails and pins, using a rabbet plane. This means the thickness of the tails and pins will be less than the thickness of the sides. Example: For a box with 3/4" thick sides, I would rabbet the ends to 1/4" deep x 1/2" wide. The pins and tails will be 1/2" long and 1/2" thick (finished), and I have a 1/4" deep dado for the bottom to sit in. With this method, you don't have to be concerned about the location of the bottom dado when laying out the dovetails.

In practice, I use a saw to set the width of the dado before planing. Because I want the ends of the tails and pins slightly proud after glue up, i cut the sides a little long, and register the inside of the saw kerf to where I want the finished interior dimension to be. This means the rough dado would be wider than the 1/2" stated above. If I end up with too wide a dado (meaning my tails/pins would be too far proud after assembly), I plane back the end of the board to give me about 1/32" proud before I cut the dovetails. Because this is my method, I lay out my sides based on the inside dimension. (Hope this makes sense to you)

I have also done stopped dados for the bottom. Rather than get overly concerned about the very end of the dado, I trim the corners of the bottom at 45 degrees to just clear the inside of the joint. With this method, there is a possibility that a very small gap at the corner would be visible when the bottom is dry and fully contracted if you use solid wood.

For a drawer, I use the same method for the front (unless I am going to put on a false front). which is thicker than the sides or back, and I don't worry about the back because not only will it not be seen, I want the bottom to be able to expand and contract under the bottom of the back (when using solid wood bottom). The dado runs in the center of the sides' pin slots (between the tails).

Hope this helps and doesn't confuse.

Go

Thanks so much for this Go. I hadn't heard of that approach before. With Dave's illustration, it makes perfect sense. Though I expect my head will explode trying to keep everything straight in my first few attempts. The 45* trick also seems like a good way to save some headaches. I'll give both of these a try....and also put a rabbet plane on my Christmas list.
Best,
Dan

 

[Mike Davis]

Just this...

So, I guess that's a no.

Sorry.

This is very clean. I need to practice my 45* cuts too. Do happen to have a photo of your pins? Thanks Mike.

 

[Gofor]

Thanks so much for this Go. I hadn't heard of that approach before. With Dave's illustration, it makes perfect sense. Though I expect my head will explode trying to keep everything straight in my first few attempts. The 45* trick also seems like a good way to save some headaches. I'll give both of these a try....and also put a rabbet plane on my Christmas list.
Best,
Dan

Let me try to do a little clarification: With the method Dave's illustration shows, you only rabbet the sides with the tails. This will result with the tails being 3/4" long, and their ends (and the pins) will be 1/2".

If you want them both the same, one of the two matching ends will have to have a rabbet wide enough to receive the whole width of the matching board (i.e 3/4"), although the tails/pins are only cut to the 1/2" depth. (Hank, hope this clears up the confusion. I missed this in my first description). This method may be preferable with finger joints, but not so much with the dovetails.

The weakness in both of these systems compared to Mike's method is in the size of the dovetails/pins.

In the method in Dave's illustration, the tails are full length but reduced in width by the depth of the groove. In the second method above, both width and length of the dovetails are reduced. In Mike's method, you have the full width of the board transferred into the corner joint from both sides, making it a stronger and more attractive joint in my opinion.

All three will work to hide the groove, just as stopped dados will. Another method is to miter all four corners and use splines, which can be dovetailed, giving the look of the tails on both sides of the joint. This method is probably the most difficult of them all to get looking/fitting good. Its advantage is that it resists the joints pulling apart from both planes, but has some of the weakness inherent in a miter joint with the end grain-to-end grain glue surface.

All just proving that the proverbial cat can be skinned many different ways.

Go

 

[danmart77]

I've seen a number of methods for hiding the ends of dadoes used for box or drawer bottoms, but I'm wondering if anyone has 'tried them all' and arrived at a preferred solution. Stopped dadoes are easy with a power router (I'm told), and possible with a router plane and chisel (I've done it but it wasn't easy). I'm after a hand tool only approach. Many thanks.

Drawer bottoms and a box bottom are different in most cases for me. I am thinking plow plane like a Stanley 45/55. I don't saw out scribed dadoes.. its a bunch of work I can avoid.

Box bottoms: you can do the "captured bottom" like Mike shows and this is a common technique when using a plywood bottom or other man-made material that doesn't expand.

Box bottom option: don't even bother with the dadoed operation and attach the bottom to the sides. After messing with the dado to fit the raised panel lid, this bottom is quick and trouble free. The veneered field wrapped in a mitered mahogany edge will not expand and pull the dovetails off the pins.

The groove concept on this box is simply an upside down drawer. Fitting the matching edge to the lid is a bear. That's why you will find so many of these boxes being built and the front edge left without a matching cove.

In my view this box with a little thumb catch carved in the lid and no edge bead just doesn't look right and says please finish me up?? I guess it comes down to the person's point of view.

​

 

[Hmerkle]

The veneered field wrapped in a mitered mahogany edge will not expand and pull the dovetails off the pins.

I want to make sure I understand - the veneered field is glued to plywood and the mahogany is then attached seperately and the bottom nailed or screwed on as the box bottom through the mahogany band?​

 

[danmart77]

True.

​

 

[Hmerkle]

True.

​

O.K. so why doesn't the wood movement tear apart the miters or the strips from the plywood?

 

[Mike Davis]

O.K. so why doesn't the wood movement tear apart the miters or the strips from the plywood?

Because wood has little movement in the length, and plywood has very little movement in any direction (the layers being in opposite directions and bound with glue restrict movement).

 

[Hmerkle]

Because wood has little movement in the length, and plywood has very little movement in any direction (the layers being in opposite directions and bound with glue restrict movement).

Note that Dan has screws both on the sides and ends of the box through the glued strips.
I would expect the plywood and the glued strips to remain stable, but I would think the box that those pieces are screwed into to move quite a bit with humidity changes. (seasonal movement)?