I had planned to write a blog about spalted timber, but didn’t have enough photos to support it and ended up being far too busy to go out and about with the camera. It’s the start of the summer gallery-exhibition season and we’re due to start making submissions to the galleries that we like to exhibit in, and we’d just bout decided which pieces we would be taking out of our stock and sticking a “RESERVED” notice on, but that was before last weekend. Over a period of two days we sold a fair few of the artistic pieces, which left the shelves a little bare. On top of that, I had students visiting for tuition last Tuesday, Wednesday and Saturday, and have another two days booked for this week, so a little midnight oil was burned.
The first piece to be mounted on the lathe was a nodule which had grown on the trunk of a Wellingtonia in a large country house. If you’re not familiar with the name “Wellingtonia”, then you might well know one of its other names, “Sequoia” and “California Giant Redwood”. The lump was a good size, but had a thick covering of bark on it, so needed a lot of trimming before I got down to solid timber.
The outside of the lump was very, very crusty and the bark yielded amazing patterns of red and orange hues amongst the plates of bark and the smell in the workshop was amazing. We’re all familiar with the sweet, heady smell of pine, but this was the strongest smelling wood I’d every turned. The steel face-plate visible in the second photo is 6″ (15cm) diameter, which gives some idea of the size of the lump. It was held securely in place with four 2″ coach-screws and just to be sure, the tailstock also pinned it in position while the bark was stripped away.
As the turning of the timber progressed, the smell got even stronger. Embedded in the grain were several pockets of crystalised resin. Many softwood trees produce resin to fill and voids caused by storm damage. If it remains in place long enough, the resin becomes a hard, whits substance and if it can be left for many, many centuries, then it turns into amber. Ours had not got that far!
The wood was a joy to turn, it cut remarkably well and needed very little sanding, which is just as well as this timber can have a very waxy feel which clogs the abrasives almost instantly.I washed the whole bowl thoroughly with cellulose thinners, which removes any dust, dissolves and cleans away superficial resin and evaporates in a matter of a minute or so. The process was repeated in the evening after making the bowl, then again in the morning, which left the surface clean enough to oil.
Once the oil was wiped onto the surface, the colour really shone out. I don’t think I’ve ever seen such a deep, rich mixture of reds and oranges in a piece of timber before.
The second bowl that I worked on was from a piece of ash recovery wood. This is wood that the host tree grows to cover over a scar where a branch has snapped (or been sawn) off. It takes many years for a large branch-end to be completely enveloped with new growth, during which time pieces of the old branch might well start to decay, then become trapped inside the wound. This was the case with our lump of ash.
The picture above shows what I encountered once I’d cut through the bark on what was to be the underside of the bowl. I would have preferred this to have been more solid, but nature doesn’t grow trees to suit woodturners.
Once work had started on hollowing the bowl, it became evident that the main void extended right through the piece, which made it potentially dangerous to work with at a normal pace, so the lathe was slowed right down to a snail-pace and cuts were made finely, and slowly. In all, the hollowing took nearly four hours, more than I’ve ever spent on a single bowl.
Eventually, the final cut was made with a gouge and I had to swap to using a solid carbide cutter because the gouges were bouncing in and out of the void, which could have resulted in the gouge tip suddenly digging in and wrenching the bowl out of the chuck that was holding it on the lathe. The carbide cutter was followed by a series of scrapers to refine the surface and then the bowl was removed for all the sanding to be done. Normally, a bowl would be sanded on the lathe, whilst rotating, but there were too many voids to trap unwary fingers, so the work was done the slow way, and took another hour.
Two very big bowls…and each very beautiful in its own way!