# Drawer bottoms



## leftcoaster (Jan 1, 2016)

When making boxes I make a dado on all four parts to receive the bottom. This means inserting the bottom during glue up.

I recently saw some FWW videos on dovetailing drawers and the bottoms went In after glue up. One side of the drawer (the back?) had was shorter, with no dado, and the bottom just slid under it.

Why do it this way? And what are the steps? Do you cut the three dados and then raise the blade to remove that section from the back side? What keeps the bottom from coming out the back again if it isn't trapped on all sides?


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## leftcoaster (Jan 1, 2016)

Here's a photo where the shorter board is being laid out with a temporary stop in the groove in the side


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## jdh122 (Sep 8, 2010)

Depends on material choice for the drawer bottom.
If you glue in a solid wood bottom in a groove in a drawer there is no room for expansion and contraction over the years and seasons. This can crack the bottom and make the drawer rack. So usually with solid wood bottoms you remove back side, install a bottom where the wood expands from front to back, cut a slot in the bottom and set a screw up into the back to hold the bottom up. Generally you also glue the front of the drawer bottom, which ensures that the expansion all occurs toward the back (otherwise you could get a gap in the front of the drawer.
For plywood bottoms I see no reason not to do a groove all around and glue the bottom in on all 4 sides.


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## ibewjon (Oct 2, 2010)

Looks like a spammer took over above. We own many old pieces of family furniture. All drawer bottoms were made this way, and it makes it easy to replace the solid wood bottoms when the wood split.


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## leftcoaster (Jan 1, 2016)

> Depends on material choice for the drawer bottom.
> If you glue in a solid wood bottom in a groove in a drawer there is no room for expansion and contraction over the years and seasons. This can crack the bottom and make the drawer rack. So usually with solid wood bottoms you remove back side, install a bottom where the wood expands from front to back, cut a slot in the bottom and set a screw up into the back to hold the bottom up. Generally you also glue the front of the drawer bottom, which ensures that the expansion all occurs toward the back (otherwise you could get a gap in the front of the drawer.
> For plywood bottoms I see no reason not to do a groove all around and glue the bottom in on all 4 sides.
> 
> - jdh122


Makes sense for solid wood. I've always used plywood bottoms.

One thing I didn't follow. If you screw the bottom to the back, how does that work with expansion? Oversized hole?


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## LittleShaver (Sep 14, 2016)

The screw is put into a slotted hole. Doesn't add much support to the bottom, mostly keeps the bottom from sliding out.


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## Lazyman (Aug 8, 2014)

If you make a solid wood drawer bottom so that end grain is in the side grooves there will be almost no movement side to side so having it free to move on the back will prevent problems with season movement. A dab of glue on the front will lock it in place so it will not come out and if you use hide glue, you can un-glue it if you ever need to replace it.


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## RichT (Oct 14, 2016)

On my mesquite side table I used glue blocks on the back as shown below. It's a technique I saw on an antique table we own. Since it's a plywood bottom, movement isn't an issue. I used hot hide glue to do rub joints to apply them.

On the antique, the bottom is solid wood with the grain running front-to-back. There is only one glue block in the middle of it to allow movement. One problem with that is that the bottom flexes due to weight and leaves gaps between it and the back of the drawer. Still, it's held up for well over 100 years, so they did something right.

If I were using a solid bottom, I'd simply turn it so the grain runs right-to-left so I could use multiple blocks without worrying about movement across the back. Then, simply leaving the bottom with a small gap in the drawer front groove would allow it to move while fixed in the rear.

One more thing. It's a groove, not a dado.


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## leftcoaster (Jan 1, 2016)

Thanks Rich-what's the difference between a groove and a dado in this case?



> On my mesquite side table I used glue blocks on the back as shown below. It s a technique I saw on an antique table we own. Since it s a plywood bottom, movement isn t an issue. I used hot hide glue to do rub joints to apply them.
> 
> On the antique, the bottom is solid wood with the grain running front-to-back. There is only one glue block in the middle of it to allow movement. One problem with that is that the bottom flexes due to weight and leaves gaps between it and the back of the drawer. Still, it s held up for well over 100 years, so they did something right.
> 
> ...


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## bandit571 (Jan 20, 2011)

Mainly…grooves go with the direction the grain does…..Dados go across the grain.

usually, when I build a drawer ( plywood bottom) sides are dovetailed to the drawer's front. Drawer back sits in a dado in the drawer sides…. bottom, being plywood, sits in a groove along the drawer front, and drawer sides.
Drawer back, sits on the plywood bottom, and into dados in the drawer sides. I usually simply screw the bottom in place, no glue…in case the bottom needs replaced.

As I don't trust a glue joint that is a butt joint, I reinforce the dado to back joints with at least 2 -3 screws, counter-sunk through the back and into the drawers back. I also bevel the back corner, of the drawer's sides…to make it easier to slide the drawer in place.

I also do not use metal slides….preferring wood webframes and kickers.


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## RichT (Oct 14, 2016)

> Thanks Rich-what s the difference between a groove and a dado in this case?
> 
> - leftcoaster


As just posted, grooves run along the grain, dados go across. However, screws are absolutely unnecessary.

You can see the construction of the front of the drawer below. The entire project is posted here. The only screws in the entire project are the ones that connect the Z-clips to secure the top. Well, I guess there's also one holding on the knob


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## bandit571 (Jan 20, 2011)

Groove








Dado…









Countersink holes









Drawer back fitted…back corner on drawer side bevel..









3/4 overlay drawer front, with pins…









And the tails, too…









Dry fit….









Have only been doing these things since the late 1970s, so, what do I know…









One thing about using screws….they are also clamps for assembly….then, once the drawer is squared up, I can add a screw to hold the bottom in place, to keep the drawer square, until the glue sets…









usually, only need two clamps…..3 at the most…..and MAYBE a diagonal one to pull things into square..









YMMV….


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## HokieKen (Apr 14, 2015)

Personally, I also use plywood for drawer bottoms and house them in grooves in all four sides. That wouldn't be a great idea if using solid wood though for expansion allowance as others have pointed out.


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## rwe2156 (May 7, 2014)

If you trap the bottom it has no room to expand.

The bottom is installed during glue up to square the drawer and firm things up.


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