TFC #28: Finding The Right Joinery Method

Cabinet joinery explored: From dadoes to lockdowel connectors

Author

Myron Wittmer
August 11, 2023

After getting an inside look at a lot of shops, I have learned that everybody has their own unique method of joinery. Most of the time, they choose their method based on what they believe is better than other methods. This could mean it is faster in the shop, it’s stronger, it is simple to design, or many other factors.

In this article, I want to discuss the common types of joinery to help everyone understand the terminology and the pros and cons of each method.

I don’t believe there is a “best” or “right” way of doing things when it comes to joinery. Each shop should simply choose the method that best fits their shop based on the capability of their manufacturing software and the equipment they have access to.

Traditional Butt-Joint

Let’s begin with the simplest method of them all. The humble butt-joint.

Their ease of execution makes this the perfect fit for someone just getting started building cabinets.

Steps:

  1. Create a list of parts

  2. Cut them out on a table saw or panel saw

  3. Start assembling using screws or staples

  4. Measure each opening and hold it in place to fasten

Pros:

  • easy to engineer

  • no CNC or special equipment needed

Cons:

  • Not as strong as other joinery

  • Difficult to cover fasteners on finished ends

  • All openings and pieces need to be measured by the person assembling

Dado Joint

The dado joint is the most common way of joining cabinets among small to medium size cabinet shops.

This method can be used by a shop with basic equipment or a shop with CNC capabilities.

  1. Design cabinet in manufacturing software

  2. Cut parts out and add dado operations

    1. Use table saw + a dado saw

    2. Use a CNC machine

  3. Start assembling using screws or staples

  4. Part can be put into the groove for exact placement without measuring

Pros:

  • stronger than butt-joint

  • no special equipment is required, but it can be helpful

  • All parts have a groove for placement to make assembly easier or more precise

Cons:

  • Difficult to cover fasteners on finished ends

  • Difficult to edgeband when dado comes to the end of a part

Blind Dado Joint (Qualified Blind Dado)

The blind dado joint works the same as a regular dado except it has a routed tenon to prevent the dado from becoming visible or affecting your edgebander.

I put the blind dado and the qualified blind dado together for this article. The only difference is a blind dado only has notches on the front and back, whereas a qualified blind dado has notches on the front and back and part of the thickness of the part is routed out.

  1. Design cabinet in manufacturing software

  2. Cut parts out on CNC

  3. Start assembling using screws or staples

  4. Part can be put into the groove for exact placement without measuring

Pros:

  • stronger than butt-joint

  • no visible routes on edges of parts

  • All parts have a groove for placement to make assembly easier or more precise

Cons:

  • Difficult to cover fasteners on finished ends

  • Difficult to do without capable software and CNC machinery

Cabineo 8/12 by Lamello

Now we start getting into the fancy connectors. The Cabineo (or Snowman, as I like to call it) is an excellent choice for someone with a 3-axis CNC but does not have the capability to do edge boring.

  1. Design cabinet in manufacturing software

  2. Cut parts out on CNC

  3. Start assembling by inserting connectors and then tightening connector screw into a 5mm hole on other part

Pros:

  • No visible fasteners on the outside of a finished end

  • All parts have a 5mm hole for placement to make assembly easier or more precise

Cons:

  • Connector is visible from the inside of the cabinet (you can buy cover caps)

  • Difficult to do without capable software and CNC machinery

Dowels

This technique involves using wooden dowels – cylindrical rods – to join pieces of wood together. By precisely drilling holes and inserting dowels, cabinetmakers create a strong and secure bond that can withstand the test of time. Dowel construction not only provides exceptional structural integrity but also offers a clean and seamless appearance, as the dowels remain hidden within the wood.

  1. Design cabinet in manufacturing software

  2. Cut parts out on CNC

  3. Send parts through edgeboring machine

  4. Start assembling by inserting dowels, adding glue and then putting the parts together

  5. Part can be put into the holes for exact placement

  6. The cabinet must then be clamped

Pros:

  • No visible fasteners on either side

  • All parts have holes for placement to make assembly easier or more precise

Cons:

  • Difficult to do without capable software and CNC machinery

  • Difficult to do without an edgeboring machine and case clamp

Lockdowel H-Clip

This clever connector is a step up from the typical dowel construction which eliminates the glue and clamping process. It's like a puzzle piece that fits perfectly, making cabinet assembly faster and simpler. Just push the pieces together, and they stay snugly in place.

  1. Design cabinet in manufacturing software

  2. Cut parts out on CNC

  3. Send parts through edgeboring machine

  4. Start assembling by inserting h-clips and pressing together

Pros:

  • No visible fasteners on either side

  • All parts have holes for placement to make assembly easier or more precise

  • No clamping required

Cons:

  • Difficult to do without capable software and CNC machinery

  • Difficult to do without an edgeboring machine

  • connectors are expensive

  • complex software requirements

Lockdowel Channellock

This is perfect for someone wanting to to RTA (ready-to-assemble) cabinets.

Designed to make cabinet construction a breeze, the ChannelLock eliminates the need for complex tools or time-consuming steps. By effortlessly sliding components into the connector's channels, cabinetmakers achieve a secure and seamless fit, ensuring flawless alignment every time.

  1. Design cabinet in manufacturing software

  2. Cut parts out on CNC

  3. Send parts through edgeboring machine

  4. Start assembling by inserting channellock and sliding into the groove

  5. After all parts in place, the press the parts into their final position and insert metal pins to prevent them from unlocking

Pros:

  • No visible fasteners on either side

  • Perfect for RTA and flatpack shipping

  • All parts have holes for placement to make assembly easier or more precise

  • No clamping required

Cons:

  • Difficult to do without capable software and CNC machinery

  • Difficult to do without an edgeboring machine

  • connectors are expensive

  • complex software requirements

Wrapping Up

There is so much more to cover and many more joinery options available but I’m going to stop here for this week. This covers a lot of the types of joinery that I typically work with.

I plan on adding a “Guides” page to my website in the near future that covers my favorite types of joinery, software, machinery and more.

Stay tuned for more info on that.

Thanks for reading and have a great weekend,
Myron