Spline and dovetail keys are basically exposed splines. After the joint is glued up, just saw or rout a slot through its edge, then glue a key into the slot. The key should be made of contrasting wood to make it stand out.
These elegant joints are difficult to cut and clamp. These jigs can help.
from the December 2003 issue
The only frame joint that doesnt leave a bit of end grain exposed is the miter joint. It is almost invisible when done correctly, making it visually appealing. You will see it used in picture frames, architectural trim, and sometimes in door or face frames.
But it can be a problematic joint.
Structurally, its a bit weak. Because it mates one tangentially cut end-grain surface (sometimes called short grain) with another, its weaker than a long-grain-to-long-grain joint. Although it is stronger than end-grain-to-end-grain, it is not as strong. You can run some fasteners through a miter joint to drive them into end grain. They won’t hold up well. Angling the fasteners helps, but not a lot.
A miter can be difficult to accurately cut. We’ve all had to deal with frames that aren’t square or joints that don’t close properly because some cuts were only half-a-degree off the mark. There are many ways to make a frame square, but none of them work.
Joint assembly can be frustrating because the mating pieces must stay in line with each other when clamping pressure is applied.
If that isnt enough to make you shy away, wood movement stresses the joint and degrades
its appearance, especially with stock that is wider than 8 cm. As the wood expands, the joint tends to open at the outside; when it contracts, the joint opens at the inside. The wider the stock and the more unstable the species, the more pronounced the effect.
It is a good idea not to reduce the stock width when joining with miters. Picture framers and trim carpenters compensate for this effect by layering several thinner mouldings to create large frames.
Download the PDF of the full article:
Frame Miter Joints
Product Recommendations
These are the tools and supplies we use every day in our shop. We may receive a commission from sales referred by our links; however, we have carefully selected these products for their usefulness and quality.
