A big part of any woodworking project is thinking about how all the parts of your finished piece will be assembled and joined together.  What is your tolerance for how much the fasteners will show?  Do you want the joinery method to be completely invisible on the finished faces or can your final finish allow for concealing and finishing over the locations of the fasteners?  Answering these questions, and the ones outlined below, will help you determine what joinery methods you’re going to employ in assembling and completing your project.

Will your wood project have a painted or a non-painted finish?

If it’s going to be painted, and you decide to simply join components together with nails or screws that will show on the finished faces, you can conceal their locations.  You will drive the screws in deeper than the surface level or use a nail set and hammer to drive the nail heads below the surface level.  Then you will fill the screw or nail holes with putty, sand it smooth and paint the surface.  This is one way to not see these joints or fasteners.

If it's going to be stained or sealed with the wood grain exposed, then considering a completely concealed joint is probably a more desirable choice.

Here are simple descriptions of three concealed joinery techniques we have used recently for projects at Runaway Ridge.

Glue Joints

Using the proper type and application of wood glue to bond two surfaces together can give you a very strong joint.  In fact, the glue joint itself can end up being stronger than the wood.  Breaking a glue joint will often fracture the wood pieces along their grain and leave the joint unphased.  A glue joint is best when the faces being joined are regular and smooth and have good continuous contact with each other.

Keeping the parts held tightly together with clamps after gluing ensures a good bond between the pieces of wood.  Seeing a little bit of glue coming out from between the two pieces is a good sign that you’ll get good bonding.  However, you want to develop a “feel” for just how much glue to use so that the amount squeezed out is kept to a minimum.

Care should be taken to wipe off the excess glue that gets squeezed out from between the surfaces being joined.  Often, these joints will need a light sanding once the glue is completely dried.  This is done not only to remove dried excess glue but also to resolve slight alignment issues between the face planes of the pieces that have been joined.

The Family Handyman website gives great written and video descriptions of woodworking techniques.  Here’s more information about glue joints:

Family Handyman - Edge Gluing Boards

Biscuit Joints

To make biscuit joints you will need: a tool called a biscuit joiner (also known as a plate joiner); biscuits (oval shaped thin pieces of compressed wood); and wood glue.  With a little bit of practice, you will become comfortable with using the joiner and making the slots for the biscuits exactly where you want them!  You will locate where you want your biscuits to be and use the tool to cut half oval slots into the middle of the thickness of the pieces being joined.  There will probably be several biscuit joints placed along the length of the area you’re joining.  You will determine how many biscuit joints you think are necessary to keep the pieces joined tightly and aligned as well as preventing them from pulling apart not only through the joining process but also throughout the lifetime of the piece.

Once the biscuit slots have been cut, you apply glue to the oval shaped biscuit, slide the biscuits into the slots and push the two mated pieces tightly together so that the biscuit is now captured between them.  The coating of the glue on the biscuit will cause the biscuit to expand in the slots and further strengthen the joint.  Glue can also be applied along the length of the pieces being joined to add additional strength to the final joint. You will clamp these pieces together until the glue is dried, the same as the glue joint.

Due to the insertion of the biscuit into the slots, with the biscuit itself being an element shared in connection between the pieces being joined and the glue that has been applied to it - the biscuit joint is stronger than a simple glue joint.  Using the biscuit joiner to cut the slots for the biscuits also controls the alignment of the pieces so that minimal sanding is required.

These biscuits have already been inserted into the stair landing compass rose.  This piece will be joined with another piece to complete the landing.  In future posts we will feature more details about the staircase design and installation.

Here’s the Family Handyman website presentation on making biscuit joints.

Family Handyman - How to Make a Biscuit Joint

Pocket Screw Joints

Pocket joinery uses screws driven through angled holes to connect pieces of wood together.  The angled holes are created on the back of the pieces being assembled in order to conceal the connections.  The mechanical fastening strength of the threading of the screws driven into the wood makes for a very strong joint.

To create pocket screw joints you will need: a special jig; an electric drill and screws.  Glue is not necessary for the functionality of this joint but is frequently added to make the joint stronger.  Due to the mechanical fastening of the screws, you can work with the joined pieces immediately and not have to wait for the glue to completely dry.  As long as the components have been carefully aligned when you set up the jig and drilled the holes - this method also assures excellent alignment.  The screws literally pull together the pieces being joined.

Pocket screw joinery is preferable for any situation where, if you have access, you can join pieces together in a method that is completely invisible on the finished face of the piece.  We have used pocket screw joinery to create large door frame assemblies and will be employing this technique to install our custom stair tread/risers on our main staircase where we can make these connections while the underside of the staircase is still exposed.

Door Frame installed on the Loft Bathroom - putty showing on nail locations where frame was attached to the wall.  Nails were “set” and then holes filled.  Frame still needs sanded and the application of the final coat of paint.

Here is a link to the same website giving illustrations and descriptions of the process of creating pocket screw joints.

Family Handyman - How to Use Pocket Screws

Conclusion

Choosing your joinery method will be based on any or all of the following:

• Your skill level
• The tools & materials you have available
• The strength of joint your item requires
• The time you can wait for the item to be ready to be handled
• Whether the final finish of your project is going to be painted or unpainted wood
• Whether you’re ok with the joints being seen or want them concealed