Address for correspondence: PO Box 8061, Hamilton 3245
NOVEMBER TIMETABLE
- Monthly meeting: AGM: Tuesday, 17 November 7 pm.
- Meetings held at: The Woodworkers' Hall, Storey Avenue, Hamilton.
- Monthly raffle ($2): Prize of $50 voucher from HAND TOOL HOUSE.
- Pre-meeting Demo: None.
- Meeting speaker: Special "Mystery Speaker and Mystery Subject!
- Project Display item: Your best work for the year.
- Sat. Chat & Turn: Saturday 7 November, 9am-noon.
ANNUAL GENERAL MEETING - 17 November
This is the highlight of our year, and members are invited to bring their partners along with some of the art and crafts that they have been involved with during the year.
It's also time for the election of officers for 2010.
AGM supper: Can you bring a plate.
We also want to hear from anyone who has suggestions for future speakers.
ITEMS WANTED, FOR SALE, DONATION or AUCTION
Let Clive Dalton know if you have any items. Get into your workshop and have that clean out that you have been planning for the last ten years! Who needs wood?
- Sanding sealer at the club for $6/bottle.
- Rob Grant has ash branches for disposal (Free). Phone (07) 856-2016.
- Brett Anderson, 753B Gordonton Road, has slabs of Swamp kauri, Macrocarpa, Matai, Kauri, and Oak (very big bits). Presumably he wants to sell it. Phone (07) 824-2289.
- Ray Irving has a dust extractor for sale. (07)828-5871
- Dowelling in Hamilton is half the price at David's Emporium compared to other shops. It seems to be very similar quality.
- Jim Kyle has an electric chainsaw (Ryobi) for $70. Bargain.
- Liquid amber timber -large tree to be cut down in the next month. Contact Barry Prior (07) 849-2714.
- Learned via disaster: Only use spirit-based polyurethane with spirit based stains and water based polyurethane with water-based stains.
DIGITAL CAMERAS (Clive Dalton)
Andy Clark and I had a session with his new camera and it's clear that one-to-one sessions are best, rather than in a group. We had coffee and apple turnovers at the Wild Bean, sorted out how the camera worked, took some pics of Club items, and then went to the Base to print them off on the fancy machine - at the cheapest price of course! He's off and running now. Let me know if you are stuck with your digital camera.
WOODTURNING CLASSES 2010
The 2009 classes have been very successful from the students' feedback and we will run one more series in 2010 at the dates below and then review developments. We are going to run a roster system as done for the Home Show, so we get a firm commitment from members willing to help, and so we don't overload the regulars. Many thanks to all those we helped out on 2009 and welcome to our new members who joined via the course.
Objective: To introduce students to the basic skills of the art and craft of woodturning
Course 1 2010
Class 1 - Tuesday 9 February
Class 2 - Tuesday 23 February
Class 3 - Tuesday 9 March
Class 4 - Tuesday 23 March
Class 5 - Tuesday 13 April
Class 6 - Tuesday 27 April
Finding students: If you know of anyone who would be interested in coming along, then let Paul Dangerfield know soon. If you think the classes are a good idea and should be saved, then volunteer to help.
WOOD MILLING. From Denis Hocking, Farm Forester. Country Wide Oct 09.
Logs are biological items and not homogeneous cylinders. Today's millers are experienced with soft woods (pine, macrocarpa and Douglas fir) and not with hardwoods (eucalypts, poplars, beech etc). Things vary greatly between the tree's central pith and the cambium (the live layer under the bark) where the wood and bark cells form. Macrocarpa and other cypresses are uniform across this radius but radiata varies greatly in density, stiffness and stability as you move from pith to 12th to 15th ring where properties tend to stabilize.
Most problematic is spiral grain where cells in these first growth rings are laid down in a spiral pattern, resulting in twisted boards and unstable timber from young trees. If you want stable pine, look at the growth rings on the end of the board to ensure it has not been cut from juvenile trees. Compression wood where cells have been squashed is the other problem with pine and other soft woods. It's usually darker in appearance and when drying shrinks longitudinally and is brittle and prone to fracture in use. Generally seen in leaning trees, it can also occur in very fast grown pines for unknown reasons.
Hardwoods, especially eucalypts have growth stresses too. In most hardwoods freshly formed wood cells shrink as they move from cambium into sapwood, so the outer wood of the trunk is under tension and to balance this the central pith area is under compression. Think of a pre-stressed concrete beam in reverse. The smaller the log diameter, the steeper this tension/compression gradient, and the more dramatic the consequences.
Cut through a small eucalypt log and the ends are likely to split in two ways and open up. Similarly when sawn longitudinally the two halves will pull back into bananas. Wood shrinks when it dries, but again hardwoods tend to shrink more than softwoods. It seems ironic but denser woods generally shrink more than lighter woods. This is because shrinkage only occurs after water in the cell cavities has been removed and the cell walls start to dry.
The thicker the cell wall, the denser the wood and greater propensity to shrink. Woods shrink more tangentially (parallel to the growth rings) than radially, and only compression wood shrinks longitudinally. So checking (cracking) tends to be more radially than tangentially. This means that you get more stable lumber when logs, especially hardwoods, are quarter sawn rather than flat sawn.
With quarter sawn, the face is at right angles to the growth rings. With flat sawn the face is parallel to the growth rings. Inevitably, many boards are intermediate. In drying you can also get collapse or 'washerboard' or corrugated surfaces, most commonly seen in certain eucalypts e.g. E. regnans and some softwoods. It's related to the fault of 'internal checking' where wood splits on the inside. So if you are milling logs, make sure the sawmiller know understands these issues as not all do, and if milling eucalypts, make sure you know the species.







