A butt joint is the most basic type of joint in woodworking and may be fastened together with nails, pin nails, staples and screws and add a some glue.
A butt joint is also the weakest joint because one of the above fasteners will be driven through the end grain of the board.
What is end grain?
A board has three types of surfaces: the face grain, the edge grain and the end grain.
The end grain is the weakest of the three.
When a fastener is driven in to the end grain it is going in the same direction as the wood fibres. There is no resistance. Fasteners can quite easily be pulled out of the end grain especially when the wood is a softwood like pine.
Fastening boards together with a pin nailer and glue is fine if these boards will not be subjected to any stresses.
I have used screws, pin nails and glue to hold butt joints together for years and I have yet to have anything fall apart. Mostly due to the fact that both the overall design and construction is well done.
So why use pocket hole joinery and something like a Kreg Jig then?
I will answer this as we move along with the course.