Upper Cabinet Construction Question

[Tim Lawler]

I am an amatuer woodworker and I am about to build some wall mounted cabinets to go over a desk in a small bedroom.

I have always used 3/4" plywood for the sides in the past. I recently purchased the following router bits from Sommerfeld Tools: a tongue and groove cabinet making set, and shaker stile, rail for doors.

Since the end panels will be visible I would like to make the cabinet sides using the shaker stile and rail cutters with 1/4" plywood panels to match or somewhat match the doors. I just was not sure whether these would be strong enough for the application. The cabinet will be roughly 6' long by 42" high, 12.5" deep. Used for books and display.

Thanks in advance for the advice,

Tim Lawler

[Jamie Buxton]

The weight of the cabinet is trying to rack the end walls. If you use plywood for the panels, and you glue them into the frames, they'll have sufficient resistance to rack to hold up the cabinet. If you use solid lumber for the panels, they have to float, and they add no strength. In that case, you'd be better off to use an inner wall of plywood for strenth, and an outer wall for show.

[Tim Lawler]

Jamie:

Thanks for replying!

I will glue my plywood panels, would I gain any strength by going to 1/2 plywood panels with a rabbet on the perimeter as opposed to 1/4" plywood?

Thanks again,

Tim Lawler

[Leo Graywacz]

This is the way I would go about it. Have the 1/2" plywood flush with the backside to produce a flush surface on the backside. If you make the styles wide enough you can use a standard 1/4" pin for a shelf. If you have to drill into the 1/2" ply you will need to use 5mm pins. I am currently making some rift oak stickley doors that are near a shaker styled door and my panels will be 1/2" and flush to the backside. I make mine 13/16" thick so I have a 5/16" front recess.

[Tim Lawler]

Leo:

Thanks for the info.

I will take a look at the layout and see if I can make that work, would the 1/2 be any stronger than the 1/4? I understand the that the flat interior would look nicer and allow for the drilling of shelf pins, but just considering budget and functionality.

Thanks in advance,

Tim Lawler

[Leo Graywacz]

If you glued it in it would make it stronger/stiffer. Most of the 1/4" plywood sold these days in really 5mm which is barely 3/16". So there is little strength to it. Plus the 1/4" is usually sold as an A-3 or an A-4 which means the backside looks like crap. If you go with an MDF panel you might be able to get it as 1/4" and it will have 2 good sides. I use to make my cabinets with 1/4" backs until 5mm became standard. Now I just use 1/2" and don't need to make stretchers anymore because the 1/2" is strong enough to support the cabinet on the wall. The 1/4" will be cheaper, but you will be more satisfied with it being done the correct way.

[Anthony Watson]

Tim,

For the cabinets I built with ends showing, I simply used solid lumber on the visible ends, and plywood on the hidden ends. If you use a hardwood plywood, it wouldn't really matter, but since I was building our cabinets with pine, a single 1x12 worked great as the side (11-1/4" deep), which gave me a 12" deep cabinet when I applied the 3/4" face frame.

I didn't bother with dado's for the main carcass. Full height sides, with the top and bottom fit between. I did rabbet the back so the 1/4" plywood back fit flush into the sides, then glued and nailed everything together. The face frame was assembled with pocket screws, then glued and nailed to the plywood carcass. Not exactly fancy joinery, but we built an entire house full of cabinets like this and haven't had any problems in four years.

Anthony

[Tim Lawler]

Leo:

I see what your are saying about both the thickness and the quality. I will probably work toward using 1/2" for strength and then I can eliminate nail rails.

Thanks again for the consult.

Best regards,

Tim Lawler

[Tim Lawler]

Anthony:

Thanks for the input. I was inquiring about using a frame & flat panel construction the same as you would use for a door on the exposed ends.

I think Jamie & Leo have answered my questions.

Best regards,

Tim Lawler