Splines and Mitres - DVD
Produced by Passion for Wood, Ontario, Canada
As reviewed in The Australian Woodworker Issue 197
The five DVDs in this set absorb a total of only three minutes less than 10 hours.
The first disc begins with a general discussion about dowel joinery and its benefits (comments that are reinforced in Thoughts on Woodworking at the end of Disc 5). Varju then shows how to set-up a drill press to produce the holes required for the dowel joints in a picture frame. Since this procedure is time-consuming (and also unable to accommodate the drilling necessary for some other types of dowelled joints), a dowel jig is suggested.
For the purposes of demonstration, the Dowelmax jig is shown in use. This jig was invented by Canadian woodworker Jim Lindsay and further information about both the jig and its inventor can be found at: www.dowelmax.com/.
DVD 2 turns the attention to mitres, a joint often favoured for its elegant appearance but one that suffers, as Varju explains, from an inherent weakness because of the partial end grain that is exposed on the joint faces.
The video explores the cutting of mitres for picture frames, the design and marking out of dowelled mitre joints, followed by the glue-up process.
The last segment in this part of the presentation deals with the cutting of mitres for boxes.
The third DVD starts by covering the gluing-up of mitred boxes. The remainder of the disc is devoted to the use of splines.
Adding one or more splines to a mitre joint substantially increases its strength. Splines can also improve the overall appearance, particularly if the timber chosen for them contrasts in colour and perhaps texture with that used for the body of the box.
A tenoning jig is used to hold the picture frames and later box frames in order to cut the kerfs for the splines on a tablesaw. While it is unlikely that many would have the exact model of jig shown, many similar jigs would perform the same duty. Mention is also made of the possibility of constructing a custom jig for the purpose - but principally for boxes that are too large to fit in commercially available jigs.
In order to be effective, both structurally and aesthetically, the splines must be uniform in thickness and fit exactly into the kerfs made to receive them. Varju shows how to achieve a perfect result using a conventional thicknesser.
The box mitres used to demonstrate the process include joints with splines of varying size and distribution showing how they can be used not only to strengthen the joints, but also to decorate the box.
At the beginning of DVD 4, the glue on the box joints is now dry and the excess on the splines is cut off with a flush cut saw. Their ends are smoothed with a hand plane - using planing techniques that ensure that the surrounding surface is not damaged (taking into account the grain direction in the host material).
Up to this point, all of the splines have been inserted in the same direction as the grain in the box sides. The remainder of the fourth disc is devoted to showing how to construct box joints using vertical splines, ie. splines that are embedded in and run the entire length of the mitre joint being visible only on the top and bottom of the box.
Again, the splines are cut flush and trimmed using a handplane followed by a little sanding.
The final joint is made by inserting a long spline between the edge of a 20mm thick sheet of cabinet-timber-faced ply and a peripheral moulding.
The grooves in the ply are made with a slot cutter in a router used freehand, while those in the moulding are made with the same cutter in a router table. The entire process is covered, from preparing the ply and moulding, to making the spline, assembling the components, routing the moulding and then carrying out the finish planing and sanding.
The scope of the whole video presentation is obviously formidable but, as usual, its value is extended by the many asides that Varju adds, in the same informal manner that you might expect of a teacher in a physical classroom situation.
Many of these are little more than explanatory comments but some offer explanations and even warnings that look well beyond the topic under discussion.
One, for example, is a review of the relationship between vertical splines and their host material showing why the size of the joints made in this way must be limited so as not to court premature failure.
Henrik Varju has earned a worldwide reputation for his instructional videos. Dowels, Splines and Mitres follows the same successful format as those that precede it, as well as exhibiting the same measured treatment of meticulous woodworking techniques employed in the pursuit of superior results.
Duration: 9hrs, 57mins, 5discs
DVD - English - NTSC