Technique: Dado joinery

A very useful joint, a dado can be through or stopped.  It's a joinery very useful for shelves or dividers (between drawers).

Many procedures can be used to achieve a dado with manual tools.  With this article we'll be looking at through dados and using two methods.

First method: This is the basic one that requires minimal tooling.  Here are the two boards that will be joined together using a chisel, hammer, square, marking gauge and a knife.




Knife marking one side of the dado.



With a pencil I mark the other side.  The pencil line will only be a guide to prevent chiselling too wide.



With a wide chisel, remove material up to the knife line.  I now have a perfectly straight wall to back the chisel.



Going deeper with your chisel.



Remove the waste.



I remove some waste while lowering the chisel angle.  The goal is to get close to the pencil line.



Insert the second board in the dado with one side butting on the wall that you've created with your chisel and make a small mark with your knife.



Dado second side have been knife marked using a square (it's right in the pencil line).



Chisel the second side just like you've done with the first side.



Oups!  I forgot to mark the depth.  This should be done at the beginning.



Keep chiselling until you're close to the depth line.



Clean the dado going across with your chisel.  Don't try to remove everything all at once.  If you don't want to get tear-outs on the leaving side, turn your board around and chisel from both sides.  The last cut will be done with the chisel in the depth line previously done with the marking gauge.



A completed dado.



Assembled.  If you're careful you'll get a crisp joint.



View from another angle.




Second method: Saw, chisel and router plane.  Knife mark one side of your dado and pencil mark the other side.



Create a knife wall using your chisel.



Mark the depth of your dado using a marking gauge.



Begin sawing lightly on the far side and stop.



Restart on the side near you.



Slowly bring your saw to horizontal and complete your cut.



Chisel the waste.



Knife mark the other side of your dado (same procedure as before) and establish a knife wall again.



Saw this side to your depth line.



Chisel the waste.



Router plane.  Set the depth stop.



Raise your cutter and begin lowering it down removing layer after layer.



If you don't want tear-outs, your router plane should be working from both ends of the dado.



Progression.



Completed dado.



Test fit.  The dado is slightly too narrow.  If it was too wide there isn't much you can do about it.



With a plane, remove a few thousands and try it again.  A hand plane is so superior to any power tools when it comes to fine adjustment like this.



Everything is now perfect.



I do prefer to use the chisel method even if it's slightly longer than using a saw and a router plane.

Normand