Shop Cabinet Construction

[tuvy guss]

I am building my first cabinets for my first shop. Here's the plan:

Use 3/4 plywood for boxes. Joinery of sides to tops/bottoms will be tongue & dado. And the back will glued and screwed.

The tongue & dado approach is from ShopNotes #103. The sides get a dado, then a tongue is milled on the top and bottom pieces to slide into the dado.

Question: for the tongue & dado joinery, do I need mechanical fasteners or is glue and clamps enough? If mechanical fasteners, what kind and how many?

TIA!

[Sonny Edmonds]

I don't know what you are talking about, Tuvy.
But in everything you build, build it in a way you will be proud to put your name on it.
You might not think it's great, but those around you will. And you'll get better and better at what you build. ;)
And don't rely on nails and screws. Do precision joinery. :)

[Leo Graywacz]

Glue and clamps will work. If you have a face frame and back on it definitely no fasteners. No FF, depends on how rough it will be treated. If it will be hung on a wall, no fasteners for the shelves/deck.

[Jim Watts]

I'd think it'd be fine w/o any mechanical fasteners, but I also think the tongue and dado would be much stronger if reversed (dado in top/bottom, tongue in sides). As you've described it (or maybe as I've interpreted it), most of the load is on the weakest part of the joint (tongue), and with little of the load-bearing benefit of the tongues' shoulders.

I'll go try to find/read the article - perhaps I'm missing something.

[Doug Rogers]

It sounds like the Sommerfeld system. The face frames all have a grove cut into them. The tongue is cut on the edge of the plywood. The joints are held together with pocket screws and glue. Check out the Sommerfeld tools website for more info.

Doug

[Jim Becker]

Glue and clamps are sufficient to hold your carcasses together just fine, especially with the grooves, dados and rabbits for the type of design you are using. (As long as they fit well) Personally, I construct cabinet carcasses with glue and pocket screws these days with an occasional old fashioned glued and screwed butt joint just for grins. I also do separate bases instead of integral toe-kicks...easier to level and simpler to cut and construct.

[Joe Scharle]

I've never seen any benefit in the half tongue dado, and have never seen any reasoning described in the mag. And I've been getting it since the '80s. Anyone know?

[glenn bradley]

Question: for the tongue & dado joinery, do I need mechanical fasteners or is glue and clamps enough?

With that joint I just use glue. No problems.

[Kevin Godshall]

I don't cut a "half-tongue" into my tops/bottoms. I make the dado full size (i.e the thickness of my top/bottom material). Saves the step of having to cut a tongue and make sure that fits to the dado.

Biggest consideration when making the box is to have the back cut and ready and MAKE SURE IT IS SQUARE. Assemble the top and bottom to the sides, attach the back, check for square (never assume), clamp pressure on sides (making sure top and bottom pieces are fully seated in the dado).

Hardest part of whole process is sizing the dado. If you're a bit over, make sure the top sits in the bottom edge of the dado, and the bottom piece is in the top. Then, when your cabinet is completed the gaps are hidden from view.

Good Luck! Let us know how you made out.

[frank shic]

i would bag the dados and just use butt joints reinforced by screws - way faster and way stronger!

[Joe Chritz]

Butt joints are plenty strong. Dadoes will help the alignment issue and are easier to assemble but so are biscuits. With an applied end or hidden sides butt joints are what I usually use.

Biscuits with a story stick for a fence/marking is very fast and easy also.

Joe

[Jason Hanko]

I've never seen any benefit in the half tongue dado, and have never seen any reasoning described in the mag. And I've been getting it since the '80s. Anyone know?
One benefit could be that you'd be sure to get a snug fit of the top/bottom in your dado in the event that you dont have the undersize straight bits for plywood. Not really an issue if you're using a dado stack, I suppose.