Cabinet building questions

[heathicus]

Today, I cleaned out the room where this is going, and moved the cabinet into place. By every way I can measure it, that thing is perfectly square. Then, I started working on the drawers.

Next question. My drawers are pretty big. About 28" wide, 12" tall, and 17" deep (keyword "about") with a divider running across the middle (from left to right, with the longest dimension). The divider was just going to slide in a dado cut on the sides, but after dry fitting a drawer, I thought joining the divider to the bottom would help strengthen it up a bit.

My material is 1/2" plywood (which is actually 15/32"). All of the drawer pieces, except the dividers and front faces, are already cut. I wish I would have gotten 3/4" (23/32) for the drawers, but what's done is done. My question is the best way to connect the bottoms to the divider.

The way I see it, I have two options. One is to cut a groove in the bottom board for the divider to sit in, then glue and screw it together. Like this:

[ATTACH]25741[/ATTACH] [ATTACH]25742[/ATTACH]

The other option is to make the bottom panel two pieces, extended the bottom of the divider even with the bottom of the front, back, and sides, and cut a very shallow groove in each side of the divider for the bottom boards. Like this:

[ATTACH]25743[/ATTACH] [ATTACH]25744[/ATTACH]

Note: All measurements in this post are approximate to help convey the scale.

I think the second option would be the strongest, but the groove would have to be very shallow since one is being cut on both sides and I don't know if that's enough of a groove to hold the bottom in place.

Thoughts or suggestions?

[BuckeyeDennis]

If you consider the two finished assemblies, and assume that the glue joints are at least as strong as the wood itself, there is essentially no difference in the strength, because the finished geometry is almost identical. With good tight joints, that is a reasonable assumption. Those shallow dados on concept #2 look like they could be weak in the pull-out direction, but because the drawer sides prevent any load in that direction, that is not an issue. You could probably go a bit deeper on those dados anyway, so long as you keep at least one vertical-grained ply intact. Either concept should hold up to most anything short of lead ingots.

Are you planning to store really heavy stuff in the drawer? If not, I'd consider leaving the bottom as a single flat piece, and not glue the divider into the dadoes on the side. That way it is removable, should you ever want to store larger stuff in the drawer.

[dusty]

Today, I cleaned out the room where this is going, and moved the cabinet into place. By every way I can measure it, that thing is perfectly square. Then, I started working on the drawers.

Next question. My drawers are pretty big. About 28" wide, 12" tall, and 17" deep (keyword "about") with a divider running across the middle (from left to right, with the longest dimension). The divider was just going to slide in a dado cut on the sides, but after dry fitting a drawer, I thought joining the divider to the bottom would help strengthen it up a bit.

My material is 1/2" plywood (which is actually 15/32"). All of the drawer pieces, except the dividers and front faces, are already cut. I wish I would have gotten 3/4" (23/32) for the drawers, but what's done is done. My question is the best way to connect the bottoms to the divider.

The way I see it, I have two options. One is to cut a groove in the bottom board for the divider to sit in, then glue and screw it together. Like this:

[ATTACH]25741[/ATTACH] [ATTACH]25742[/ATTACH]

The other option is to make the bottom panel two pieces, extended the bottom of the divider even with the bottom of the front, back, and sides, and cut a very shallow groove in each side of the divider for the bottom boards. Like this:

[ATTACH]25743[/ATTACH] [ATTACH]25744[/ATTACH]

Note: All measurements in this post are approximate to help convey the scale.

I think the second option would be the strongest, but the groove would have to be very shallow since one is being cut on both sides and I don't know if that's enough of a groove to hold the bottom in place.

Thoughts or suggestions?

I would prefer the configuration in the last image. I think you might be amazed at just how strong that shallow dado would be. As long as the sides do not spread apart the shelf will not come out of the dado. But, you could always reinforce the shelf with some hidden strips.

All of the integrity in the finished project is reliant on the glue job. I tend to use too much glue and then have unsightly traces of glue but I never have a weak glue joint. Yes, there is a happy middle ground.

[JPG]

Gonna be a contrarian here. I would prefer #1(solid bottom).

The groove need not be as deep as shown. All the groove does is prevent the divider from moving front/rear. I think 1/8" is more than adequate for that.

I also think 1/2" thickness of the divider is excessive(but likely what is on hand).

My reason is that a continuous bottom will not rely on glue jointS. Since these drawers are to be supported by slides mounted to the sides, the bottom is only supported there.

I vote for not gluing the divider as well.

[heathicus]

The contents of each drawer will be around 80 lbs. The divider was initially going to be hardboard, but I have just enough 1/2" (15/32") ply left over and have the room in the drawer to use it, and I was starting to worry about the strength of the drawer, so thought I might use that for the divider instead and use it for additional reinforcement.

My ply is pine sheathing, not oak or BB or anything like that. That was the best I could afford right now.

[bffulgham]

Gonna be a contrarian here. I would prefer #1(solid bottom).

The groove need not be as deep as shown. All the groove does is prevent the divider from moving front/rear. I think 1/8" is more than adequate for that.

I also think 1/2" thickness of the divider is excessive(but likely what is on hand).

My reason is that a continuous bottom will not rely on glue jointS. Since these drawers are to be supported by slides mounted to the sides, the bottom is only supported there.

I vote for not gluing the divider as well.

+1 vote for the solid bottom.

I would, however, glue the divider. Your anticipated load of 80# in the drawer.....gluing the divider would add some support/stiffness to the entire structure. Or, screwing.

[Ed in Tampa]

+1 vote for the solid bottom.

I would, however, glue the divider. Your anticipated load of 80# in the drawer.....gluing the divider would add some support/stiffness to the entire structure. Or, screwing.

I too vote for the solid bottom. However I would run a wood strip across the bottom from side to side both in the front and back. I know you are going to have a face frame to support the bottom at the front but I would want the cabinet to support itself without the face frame.

When I built my bathroom cabinet I used a treated 2x4 base butt jointed, then built the cabinet on top. I set back the 2x4 on the cabinet front enough that when the face frame was installed I had a proper toe kick I then covered the toe kick with ceramic tile that was on the floor.

Any water leakage in the bathroom will only hit the treated 2x4 unless it get over 3.5 inches deep. Plus I was building on slab floor over concrete and needed the wood in contact with theconcrete to be treated.

The point was the cabinet was rock solid and all the face frame did was finish the front and make the thing all that more solid.

If you don't add a strip under the front and back edge the only thing that supports the bottom is bottom itself plus what support you can get from the face frame.

[JPG]

Somebody be confused(maybe me?:eek:). This is a drawer that will be supported on slides attached to the sides. No other support will be 'available'. Base and face frame* are not relevant. Neither is a flood(I am not aware it will be near any source of water;)).

* Unless the 'face frame' is the drawer front?

[berry]

My question is with the two inside carcass divider panels. Is there a "best practice" for locating them in relation to the edges of the face frame? Should they be centered and have spacers installed on both sides for the drawer slides? Should they be put flush with one edge of the face frame and the drawer slide mount directly to it on one side and a spacer on the other side?

I don't think I can answer the question about "best practice" but I can say I just finished a bathroom vanity that required drawer slides mounted, where I needed a fake wall. I ran a piece of the material I was using for the case (3/4" pw from the face frame to the rear of the cabinet I added a spacer. See pics.

[ATTACH]25753[/ATTACH]

[ATTACH]25754[/ATTACH]

[ATTACH]25755[/ATTACH]

[ATTACH]25756[/ATTACH]

I build the face frame first. Where the case members meet the face frame I cut tongues on the case members and grooves on the face frame pieces. This extra work insures good fit, square builds and very strong cabinets. I kinda follow Marc Sommerfeld's idea. https://www.youtube.com/watch?v=klv0jzWD26w

Just to be clear I am not now nor have I ever been an employee of his nor have I received any compensation from him at any time. If you can stand listening to him the process is pretty slick.


Good luck with your project, cabinets are always fulfilling builds.

[forrestb]

You could probably go a bit deeper on those dados anyway, so long as you keep at least one vertical-grained ply intact. Either concept should hold up to most anything short of lead ingots.

I really would not try to cut dadoes on both sides leaving "at least on vertical-grained ply intact" since I believe cutting the second dado would destroy the first.

I am of the opinion (thank goodness we can keep that freedom - at least on this sight:rolleyes: ) that option 1 gives you a stronger unit and can even be made stronger with screws if need be.

Forrest