As a gift, I purchased a large piece of burl wood from southeastern United States Cherry. I have written fairly exhaustively about Cherry in the past and that information can be found here.
Anytime one works with burl wood one frequently encounters conditions and circumstances that are not normally encountered when working with non-burl wood even from the same species. That said, while the information referenced above is all quite accurate for regular cherry wood, burl wood is a beast of a different color owing to frequent voids or areas of instability that become voids as well as twisting interlocked grain and figure. But it is exactly these variations that make burl wood so very attractive to wood-turners with prices and scarce availability to match.
This piece featured some voids before the turning process began and it also developed additional voids during turning. It is a credit to the skill and experience of the turner, Steve, that the finished piece is in one piece at all. And fair disclosure, I am not unbiased about this work or the artist who made it: he’s my Dad.
Cherry Burl Side View – Steve Staley
When approaching burl wood for turning, one MUST bear in mind that what can be seen from the exterior is no guarantee, at all, of what you will find in the interior. The wood turner may, not infrequently, encounter very unstable material that will fall, or fly, out from the main piece while turning. There may be outright voids that are unexpected. And, most dangerous of all, dirt and even small rocks are to be expected, especially in root burl pieces. Eye protection is an absolute MUST when wood turning, especially when using burl wood.
One way to help mitigate some of the common problems encountered with burl wood is to fairly well soak it in cyanoacrylate, better known as “super-glue.” The brand doesn’t matter. Apply as much as possible to any visible crack and hope that it runs down into voids and areas of instability you can’t see. Thin consistency material is best for this application. I also use a medium to thick material for larger gaps or holes I can see on the surface. Cyanoacrylate will not discolor most woods and besides most of it will be turned away regardless. And for any discoloration that does occur, without the use of the glue you are likely to have nothing but expensive scraps. Use the glue.
Mounting these pieces can be a challenge because you often don’t have a flat surface to start. You can cut a flat surface if you have a saw capable of SAFELY making such a cut. Use extreme caution when doing this because saw blades that encounter sudden changes in resistance, or rocks, can create extreme hazards extremely quickly. If it isn’t safe to make such a flat surface cut due to the material, to a lack of adequate tools, or a lack of experience working with burls, don’t attempt it. No project is worth injury.
Cherry Burl Reverse – Steve Staley
A way to mount such a piece quite safely is to use a screw chuck, of which there are several varieties. The Nova Chuck systems come with a screw chuck capability included, the so called Safe Lock Woodworm Screw, you can purchase a purpose made model from vendors such as Craft Supply USA. I have both types and use them both successfully. Screw chucks allow you to mount pieces that lack a flat surface and then use the lathe to create a flat surface suitable for face plate mounting. The area in which the screw is installed in then simply turned away.