I wouldn’t blame anyone for thinking that draw boring is one of those traditional techniques kept alive only as an ambition for keeping the old stuff in use. After all I’m sure there could be arguement to say that with our good modern glues teamed with the accessibility of descent clamps we just don’t need to put in the extra effort. Or, if you do fancy some reinforcement why not just glue, clamp and then drill through for the pegs together?
Without going in to too much detail (that’s another post) draw boring adds an extra step to simply knocking a peg straight through a mortice and tenon joint. The important part is in positioning the holes off-set, with the hole through the tenon being slightly closer to the shoulder than the hole through the mortice. When the peg is hammered through it has to bend it’s way in to the holes which pulls the joint up extremely tight and holds it there.
I always love to see a mechanical nature to a joint rather than relying soley on glue so I’m a fan of draw boring. And though glue might be able to hold joints tightly for us these days there’s one particular advantage of this method which I find still makes it far better for certain circumstances.
Today I’ve been assembling trestles for the Little John workbenches. Without the use of draw boring my day would have given me one hell of a headache. First there’s the splayed back leg to deal with and then there’s the large quantity which I’ve had to bring together.
Using glue alone in the joints would mean the use of clamps. Drawing boring is a fantastic alternative and the beauty is you can ditch the clamps altogether. The pegs pull the joint up tight and hold it in place while the glue drys. That’s a lot less faff and a lot less space than having to use clamps and I’m especially grateful when doing this mass of angled legs.
Mastering traditional techniques isn’t all about recreating every process for the sake of doing it the ‘old way’. For me it’s about taking out the relevant elements which can be used to benefit the efficiency in your workshop today.