When creating scarf joints in long runs of base, I find it tricky to maintain alignment, and as a weak point in the run, a scarf joint is at risk of opening up due to seasonal changes. To overcome these problems, I cut the scarf at 45°, clamp the two halves together, and cut a deep biscuit slot in the bottom edge across the miter. As shown in the drawing below, this slot allows a biscuit to be buried into the baseboard, thus aiding alignment and providing a much stronger glued joint.
Robert Gunn, Mississauga, None
Edited and Illustrated by Charles Miller
From Fine Homebuilding #253
View Comments
I like this idea. But instead of cutting, aligning and clamping the pieces together to cut the biscuit slot, why not cut the biscuit slot first then you can skip the careful alignment and clamping steps.
The picture is throwing me off a bit. Is that a compound miter cut (45° scarf and a 45° Board cut?). Or, is it just the typical 45° scarf?
You can’t use the biscuit joiner to perfectly align a scarf joint. It is too inaccurate.