Categories
Furniture/Cabinet Making Woodturning

Woodturning a Platter

A suitable diameter for wooden platters generally is about 12-13 inches i.e. ~300 mm; but why choose 19 mm wood? This is the thinnest dressed wood that is practical, and readily available, for platter turning. Often this thickness is available in 300 mm (or greater) widths meaning that a 300 mm blank etc can be readily cut out on a band saw. Where lesser widths of suitable wood is only available good/strong lamination can be applied using similar or contrasting wood or woods to make-up the diameter to ~300 mm.

For this demonstration Queensland Kauri was used which had a pronounced but subtle grain. Using 19 mm wood the turner needs to be very cautious of the depth of cuts both on the face and the underside of the turning to ensure a final thickness of 5 mm minimum to look worthy of its design and to feel practical when handled or appraised, ie low density timbers will most likely be  unsuitable. The demonstration’s turning techniques followed those given in the DVD. Care needs to be taken with accurate chucking as there is little, if any, spare wood to turn away to get correct squareness. An aluminium/hot melt glue chuck (face-ring) was used which did not protrude into the wood on the face side for turning the base. For the base chucking, a VM100 chuck with larger 100 mm circular expansion jaws was used. These jaws fit nicely by allowing the continuous circular footing to be 15 mm wide and slightly greater than one third of the diameter of the platter. The chuck recess needs to be between 3 to 4 mm deep, and for these jaws dovetailed at 77 degrees. Take care to get the dovetail precisely formed, square and with all chips removed from the depth of the recess.

To turn the base check for ‘squareness’ and adjust the aluminium face-ring in the jaws if necessary. From the centre measure a 100 mm diameter pencil line to accommodate the chuck; then measure and mark the 130 mm diameter for the outside of the platter’s foot. Between this 130 mm line and the ~300 mm diameter of the blank add lines to assist with profile turning of the underside, viz simple slope, Roman Ogee, or other, all of which need to fit with the later turning of the face of the platter. For this platter, because the thickness is restricted with an initial 19 mm, a simple underside was chosen with a somewhat thicker reinforcing ring between 130 and 180 mm diameter where the the face depth will approach its maximum. Note that the depth within the recess for the 100 mm chuck is convex and virtually nil at the centre to add thickness and strength to the turning.

A gentle curved underside from the 180 mm mark to the periphery is planned to give a ~5 mm thickness of the final piece. Plans for the platter’s ‘face’ is also to have a gentle but concave curve to achieve this 5 mm final thickness across its diameter. Rims, beads and deeper turning is virtually impossible as only about 14 mm maximum is available to remove on the top side of the platter i.e. 14 mm plus 5 mm for the base recess at its edges uses-up the whole thickness of the blank!

 

Care needs to be taken with the face curve which needs to be continuous, without any irregular
bumps or ridges and sanded to a very fine finish. Run through the grits to at least 400 followed by
brushing away all the dust in between, consider burnishing with wood chips and/or using 0000 Steel Wool, and finally using EEE and UBeaut Shellowax. The result should be a pale cream, thin and lite weight platter which because of its continuous slight curved surface shows its subtle straight grain to advantage. Another similar platter (turned previously from Australian Red Cedar) is shown which also exhibits pleasant grain together with a contrasting minor edge of its sapwood. This platter was finished similarly but with a final coat of UBeaut Glow which may show darker woods to better advantage. Another point of interest for ‘thin’ platters is the ability to cut and colour and even move the wood. Note how in the above platter apart from the colouring some wood has been carved away to form the tree trunks allowing the tree branch foliage to be moved across the platter and glued in a new position to produce a creative platter.

Lindsay Skinner, Hornsby District Woodturners Inc. President and Convener

We should all try this project using 19 mm boards which can result in a pleasant display of design and of the woods’ values and beauty.

Categories
Woodturning Woodworking

Selecting and Drying Turning Woods

By Greg Croker

Regarding the selection of wood for turning there is mostly no choice as the tree to be felled is selected for a non-turning requirement or has blown over during a storm etc.

Which are the better species of trees to select?

In our area eucalyptus trees are predominant with the acacias next? Native hardwoods and other harder wood trees are to be avoided unless needed for a specific reason so that leaves just a few native softer woods ideal for selection: Australian red cedar, silky oak and native frangipani are examples to be discussed here while soft wood exotic street or garden trees offer quite a wide range with jacaranda, camphor laurel, maples, liquid ambers, plane trees, oaks and African olive being possibly the most popular.

As many eucalyptus woods finish beautifully, and as their (turning) hardness (when dry) can be overcome by turning when wet (and softer), consideration should be given to this species particularly if wet rough turning is proposed.

Where we are able to view the tree standing, plans can be made as to the ‘handling’ of the straight trunk, cutting close to the ground/roots, the availability of crotches, the possibilities of the larger branch wood and even the use of the root ball for turning with associated carving and/or nowadays coloured epoxy to fill the voids. The separation of burls from the trunk if present, is as we know, most rewarding.

Northern hemisphere literature states that ‘where possible fell trees in the winter months when the sap is not rising’ but for more temperate climates like Sydney’s this may not apply even with deciduous species. Large standing trees will most likely be felled in lengths from about say 200mm to one or two meter lengths dependent on the trunk diameter and weight and should be suitable for most turners. Decide what you want and have a couple of friends help with the lifting. 200 mm lengths can be split on site and carried easily while the longer lengths may need to be sawn longitudinally down the centre/pith to be carried and transported. If sawing ‘along’ the trunk try to cut each side of the central pith thus producing a slice of quarter sawn heartwood each side of the pith and useful for platter turning particularly if the diameter is over 400 mm. Thinner branches less than 130 mm are generally not suitable once dry other than for small turnings such as tween and small items with retained bark etc.

Trees already felled need to be handled similarly, noting that a one meter length of trunk can be slipped with help into most car boots. The selection of other sections of the tree may be more difficult to handle without extra manpower present. In this case one meter lengths can be conveniently taken from site and sawn into billets or slabs etc at the Shed or other workshops prior to turning or drying. Cut or split wood available on nature strips in short lengths for fireplaces (see photo) may be suitable if collected very soon after cutting before major cracks develop. Check for grain direction too.

Once the wood has been obtained either as ‘shorts,’ 100 mm thick slabs, one meter logs or half logs etc. it is most important to end seal ASAP. Wet wood splits quickly often 15 minutes or less after cutting. Handling in the car boot or trailer should also be quick and the cut wood kept cool and out of the sun until suitably sealed and stored. Whole logs do not store well and can crack its entire one meter length so it is best to saw into halves, planks or billets. In each case allow about 10% extra in length and width for cracking wastage.

If the wood is to be held for some time paint with another layer of end sealer, and store in a cool, dry and low draft area mounted clear of the ground. Allow air to circulate between the wood and mount on bricks or metal under the house floor until wet-turned or fully dried. Woods left to dry naturally in this situation will generally crack somewhat and take about 2 years per 25 mm thickness to dry, so this is where accelerated drying can be very useful.

There are a number of procedures proposed for quick drying not all of which are ideal for a perfectly turned item. For today the discussion will be on two methods suitable for all turners to easily adopt.

Method 1 is the use of wet turning of the blank by ruffing out a bowl on the lathe soon after collection. Prior to turning, trim the wet blank on the bandsaw to make it approximately circular and slightly greater than the finished bowl in diameter. For orthodox bowl turning mount the blank with a Glasser screw (or if needed a faceplate) and turn the bark and the wood away to the approximate outside shape proposed including a strong spigot. Generally a continuous spray of liquid is spun from the bowl and a face mask is necessary particularly turning the outside and a waterproof cover is advisable to protect the rails from rusting; don’t use a towel as this can get caught in the spinning turning and cause operator harm.

Remove the screw or the faceplate and reverse the blank securing it carefully in the chuck jaws and commence turning the inside of the bowl. Complete the inside turning following the outside shape as uniformly as possible, and about 10% thicker than the proposed final wall thickness to allow for oval warping. Ensure that the base of the bowl is not excessively thick as this will slow base-drying and may cause cracking. Should the bowl be looking dry at this stage of turning, or if there is a delay in turning anticipated (i.e. lunch) wet the bowl with a fine water spray and/or cover it with a damp cloth to re-establish the moisture level thus preventing cracking.

Clean up the rim of the bowl and end seal inside and out, remove from the chuck and seal around the spigot. As most of the bowl is endgrain? complete sealing will approximately equalise and slow the rate of drying from all the surface. You should at this stage weigh the bowl on sensitive kitchen scales (say +- 2 gm) and record the weight and date.

Immediately or as soon as possible, prepare a 30 – 40 litre plastic garbage bag by placing a generous 3 or 4 handfuls of wet shavings from the bowl plus a wet but not dripping newspaper (say ~50 sheets of tabloid, the SMH is suitable) into the bag followed by the bowl (kept clear of the paper but not necessarily the shavings) and tie the bag all but closed, say a 25mm diameter opening. Store the bag in a cool part of the house. This will allow the bowl(s) to commence drying evenly and generally without cracks or gross warping in an atmosphere of virtually 100% humidity. Up to 3 bowls can be dried in each bag, dependent on size.

Every fortnight or month check on the bag’s contents and look for cracking, mould or spalting and correct where possible. Weigh the bowls and record as above. If the paper and shavings are somewhat dry dampen with water and replace with the bowl(s) and again all but seal the bag and
allow to continue drying. Each month after checking the bag should be ‘reset’ and as the bowls’ dry, the bag’s opening can be increased say by 10% allowing slightly more moist air to escape so that the rate of bowl weight loss does not cease or drop down to near zero between times.

As the bowls become closer to fully dry the rate of drying reduces considerably such that after 6 or 8 months each bowls’ monthly weight reduction approaches only 10 or 15g (for a bowl about 700 g initially). A few months’ later the bowls’ weights become all but stable altering only as the percent relative humidity of the air rises or falls. During this drying phase the paper and shavings can be allowed to dry somewhat too.

Now, (about one year after rough wet-turning and bagging) the bowls are all but dry and stable and can be removed from the bag and allowed to condition in same area for another month prior to their final turning and normal finishing.

The graphs of bowls’ weight reduction vary considerably. Bowls with thicker walls than one inch will take longer to dry and presumably drying time will vary by wood species and the humidity inside the plastic bag. The use of a moisture meter can be of help giving a guide to the water content. For heavier and larger wet-turned bowls the use of lidded tote bins can be more practical. The same principles apply and the lid can be progressively opened as the wood dries.

Method 2. The Solar Method again consists of a 50 L non-woven plastic bag with the wet-turned
roughed-out bowl or two inside and sealed at the top. But in this case the bag is placed in the sun to evaporate moisture from the turning(s) which condenses on the cooler parts of the bag’s inside and the condensate then drains down the bag and exits via a small hole in the base of the bag.

Practicably the bag is best hung on the clothes line. As expected the humidity inside the bag during sunlight hours will be close to 100% which will reduce the rate of moisture exit from the turning and preventing parts of the turning drying faster or slower thus reducing cracking and/or gross deformation potential. This can be a quick procedure dependent on the sun but is fast at removing the initial height percentage of the wood’s water content which may be removed in a month or so. An idea of the weight loss at any time can be estimated by weighing the bag and contents prior to commencing and at any time during the solar treatment. Electronic scales with a hook are ideal (i.e. hand held suitcase scales) for checking the in-process weight losses without disturbing the contents. These can be found with a sensitivity of +- 10g and are ideal. Once the condensate flowing from the bag reduces to almost nil the bowls can be removed and further dried using Method 1 above.

Other Common Accelerated Drying Methods.

Method 3. Microwaving. Many turners have tried or use this method. I have experimented with this procedure following all the ‘rules’ but without satisfaction.

Method 4. Boiling With Soapy Water. Used by a few turners, deformation in shape and wood texture needs to be allowed for. Quick and dry after about 2 months then ready for turning. Boiling time varies as it is necessary to breakdown and remove sap and other structures in the wood.

Method 5. Soaking in Alcohol (Methylated Spirits, 98% ethanol + 2% methanol). Reputed to give
good results. The alcohol penetrates into the wood and dissolves the sap etc while the alcohol
displaces the water as well as subsequently drying faster. Takes a week or two to get a dry product. Needs some instructions. Alcohol is a fire hazard.

Method 6. Poly Ethylene Glycol Soaking. No experience but the literature details difficulty with
turning and slippery finishes. PEG replaces the water in the wood and stabilises its shape.

Method 7. Silica Gel Drying. This is a granular solid that can absorb water from substances quickly. 1 Kg will absorb up to 400 g of water from a wet atmosphere in about 24 hours, and is reusable after heat regeneration. Some simple detail re bowl drying on You tube but needs more detail and technical advice. Worth following-up.

Method 8. Kiln Drying. Requires lots of wood knowledge and a fair amount of capital. Some craft
interest with simple kilns using incandescent 60 watt light globes for heating.

Method 9. Refrigerated Drying. Closed circuit air is blown over the wet wood evaporating some moisture. This air is then cycled over the ‘fridge’ cooling coils condensing some of the vapour to water which is drained away. This cold air is then circulated over the ‘hot frig’ coils and warmed, thus lowering its Relative Humidity, before being recycled over the wet wood again. The process is repeated until the wood is dried. This could be an interesting technique particularly if you can find a small spare refrigeration system to adapt.

For details on kiln drying on a larger scale checkout Google on ‘Fundamental Aspects of Kiln Drying of Lumber.’

 

Categories
Member's Stories Woodturning

Developing a Style in Wood Turning by Simon Begg

I have been turning for ten years’ now and, in that time, I have tried many different designs and styles. Some I love and have spent countless hours developing then there are others that remain hidden away on a bookshelf at my parents’ place. Of the first two designs that I ever had accepted into galleries, one style was a commercial success – I can’t make enough of them and the other just never sold. There are many elements to be considered that may lead to great design and also characteristics that can be worth developing.

Before I get into all that, a bit more about myself for those who don’t know me because it’s been too long between visits. I joined the Club (HWMS in Jul 2015) when I was 16 which, at that time, made me the youngest member by quite a margin. I learned the basics of turning and spent a lot of my time on the lathe making all sorts of basic projects. I learned quickly as I was always challenging my abilities, trying something a bit more difficult every time I was working on the lathe.

I loved woodworking so much that I dedicated most of my final year at school to my major project in woodwork where I was placed second in the State. From there I began to train as a cabinetmaker and completed my apprenticeship. After attending Turnfest in Queensland, I quit my job and started full time woodturning in 2016. In 2019 I was chosen to be one of the Turnfest demonstrators and this year (2020), I will be traveling to the USA to teach at the AAW Symposium and the Mid-Atlantic Symposium. These teaching opportunities are where I will be able to share some of the styles and techniques that I have been developing over the last few years.

Before trying to develop your own style of work, you have to master the tool control and knowledge of timber that only comes from much practice and experience on the tools. There are also great opportunities to learn from other turners that have made some similar mistakes before. A lot of the time we look back to our original works to see how far we had come. My bowls use to be fairly straight walled and flat bottomed, typical of most beginners. Eventually good design and shapes came into the forms that I made. Well-shaped curves, consistent wall thickness and appropriate foot sizes are important in that development of design. These aspects can be learned though others’ works, even in other mediums.

After gaining an understanding of how to get good form and clean cuts into the bowls and platters, that’s when I started to find my own style. At first, for me, that really came from adding carved embellishments. The first design that I really liked was my dot series. It was as simple as carving a few dots with my $40 Ozito rotary tool that followed the patterns in the grain. Here are pictures of my first and one of my more recent ones.

These designs were inspired by 2 photos that I found by searching woodturning on Google. I saw a texture that was carved to follow a section of grain rather than a perimeter of a bowl. This intrigued me and I found a piece of cedar with some interesting wavy grain. I turned a simple shape that I found highlighted the grain. Rather than just carve one band like I saw on the other works, I decided to carve every couple of growth rings. I was so happy with how it worked out and that’s how I developed my first design. Since then I have refined the shape with a larger rim to have a greater change in direction of the grain. I also look for particular cuts of wood. To me quarter sawn timber is boring in comparison with the back sawn timber that I use.

I think I have now carved about 100,000 dots in similar bowls, including a few 530 mm diameter bowls that have about 3,000 dots each. I loved how basic texturing could transform a good piece into a really great piece that was quite unique. I found my niche in the market as most people that added carved embellishment do very detailed relief carving. I was just adding a basic pattern. By experimenting with different cutters and tools, I found other patterns that I really liked. I would always have a scrap board next to me as I worked to test out new ideas that came to mind. By understanding the capacity of the carver and the different bits, I could develop ideas as I worked on the process of others. As they are simple, I found the carving would be quite quick and a small bowl like this rosewood one would only take me about an hour to turn and carve.

After meeting Nick Agar in 2017 I saw that a lot of his textures were inspired by nature. Half of his travel photos were of the ground, plants or structures. I realised that inspiration can come from anywhere and anything. On my next holiday, I found a texture that I really liked in the rockpools in Kiama where I had holidayed since I was three. I used my knowledge of the carving tool to add that into the rim of a bowl. It is a rough, organic shape so, if I slipped, it looked as if it was intentional, hidden in the design.

My next nature inspired design was when I went for a walk and saw some dried-up mud. With the country going through drought, I thought that it would be a texture that would capture an element of Australia. The lines were simple enough with a star cutter but the challenge came in scalloping the individual sections. With these complex textures, it’s all about layering techniques to get the final result. A few experiments later, I had a seven step process to get the pattern I was after. The red cedar once again was a perfect choice of timber to match the style of the carving.


As well as finding a style through carving, one of the techniques that I am gaining recognition for is German ring turning. It’s a 200 year old production method for making toys. I stumbled across it when looking at other turning ideas and thought how it could be used for sculpture. I also was interested by the technique as it would challenge my abilities, just as I was doing ten years ago, trying to push myself to achieve the next level. This technique involves turning a detailed ring that, when cut in half, reveals a profile. I had to develop my own methods as there was very little information available so now I was aiming to attain new levels of detail in the technique.


It’s not a brand new technique but with the direction I’m taking it, it’s recognisable as my original style of work. It’s the same with the carved embellishment, the techniques that I use are not new, but they are being used in different ways. Coming up with something brand new is not likely. With finding your own style, it’s a matter of doing something that has been done before in a slightly different way. It’s amazing that even a small difference in technique or design can make even a simple bowl recognisable as the work of a particular turner. There are some very creative turners out there and I recommend looking at their works to see what is out there.

Turnfest really opened my eyes to the possibilities and I would highly recommend experiencing that just once. I strongly recommend trying new things to develop your own style for what you make. Challenge yourself in all that you do and always strive to learn. Don’t be afraid if it doesn’t work straight away because it often doesn’t. Look at what others are doing and think how you could change it or blend it. The more you turn and experiment, the easier it gets. Hopefully these tips will help in finding your own style in wood turning.

Categories
Woodturning

Woodturning with Brendan Venner

Recently Brendon Venner demonstrated techniques he applies in his woodturning ‘life.’

Brendon showed a complex musk burl bowl about 180 mm in diameter with protruding ‘legs and flanges’ accomplished using AutoCad Computer Design to draw his proposal and then develop an initial design, while on the
computer, to give the best design possible as well as getting what he wants from the turning. Printing the Cad plan full size, and turning a prototype bowl in radiata pine, also allows scope for further design improvement prior to working on the musk blank. These planning and design stages generally take some weeks, prior to turning!

For this turning the bowl profile giving the best viewing was elliptical and completed by turning to the diameter of the ‘protruding four arms’ and routering away the wood between to get the desired result. The bowl’s inside was turned normally. While Brendon uses AutoCad Design he recommends DraftSight Draw Tools as more than satisfactory and is free from the web.

Brendan introduced us to fractal burning, known as Lichtenberg Fractals these patterns add substantially to the detail carried on this turning. Brendon demonstrated this ‘electrical’ technique on a number of different woods.

For the equipment a 10,000 volt neon sign transformer is required. This is connected via insulated and approved cables to electrodes of steel. The wood is made conductive (particularly for dry wood) by rubbing into the surface an electrolyte which can be any ‘chemical salt’ solution such as baking powder (~10 g per 200 ml or straight Pepsi etc) which is allowed to absorb into the wood before commencing. Connect one terminal (electrode) permanently to the wood turn on the power and carefully move the other over the wet wood surface to give fractal patterns as desired. Beware of the bare metal electrodes or these will soon remind you with a nasty shock. By adding an input voltage regulator, in this case a sewing machine pedal controller, the ‘ferocity’ of the burn can be moderated allowing finer fractals. When finished clean away the burnt wood/charcoal with a fine brush and sponge completely free of electrolyte, dry and finish as usual. Remember caution is necessary with this technique as electrocution is not entirely unknown!

Surface colouration was next demonstrated. As an example a small pine goblet was turned externally and air brushed with a number of contrasting colours along the turning. Once the paint is dry, spray and seal with two coats of clear gloss lacquer and once dry artistically glue hot melt from a glue gun over the length of the goblet. Wait for the hot melt to set and harden. Spray completely with black acrylic semigloss ensuring that there are no coloured shadows remaining, and allow to completely dry, say 6 to 8 hours. Carefully remove, by hand and/or with a scalpel, all the hot melt glue to expose the colour below the glue. Spray with a top-coat satin finish clear acrylic lacquer and when dry polish the goblet with a wax polish to finish.

For platters with a wide flange of colours and a smaller diameter internal bowl start with the basic design allowing a flange of approximately 80 mm wide. Sand to 400 grit and paint the entire surface with black spray acrylic as a contrasting base. Mark out the diameter where the centre of the platter is to be turned down and ‘preserve’ it. On the remaining annulus flange ladle multiple 1 ml quantities of Acrylic Flow Medium all around to form a pleasing patten. Add acrylic colouring, drop by drop (to give a 50:50 mix), to each flow medium ‘blob’ and use the dry air brush to blow these various coloured blobs into each other and/or around the flange to give a random wavy effect which when dried and sealed will give a spectacular result. The colours used should be Joe Sonyas ‘Iridescent’ type or equivalent to give the result shown on the platters. Once the colours on the flange have been completed turn out the ‘preserved’ centre of the platter, sand and seal to
finish the turning. The Flow medium can be substituted with water to cover a larger area which if immediately covered with Gladwrap and pummelled with the fingers to cover the complete black base can give an outcome not dissimilar to the previous platter. Also flick colouration using a toothbrush can be used to give another interesting result, including the Australian cedar ‘flick ebonisied’ bowl shown. Checkout similar ideas from Gary Low’s You-Tubes https://youtu.be/S2lB4Smq6TI. It is noted that Brendon was using the air brushing system available recently from Aldi Stores for approximately $80.

A big thank you to Brendan for his fascinating demonstration.

 

Categories
Woodturning

A Woodturning Project with a Difference

Categories
Woodturning

How to Make a Cube in a Cube

Enjoy this video on how to make a Cube in a Cube with a Forstner bit in the drill press.

Categories
Woodturning

How to make a metal cube from a cylinder

Were you under the impression you could only make round shapes on a lathe? This metalworker has created the ultimate cube-ception. If you would like to guess how it is done, think about how you would make a cube from a cylinder, and go from there. It gets trickier and trickier the more cubes within cubes you make. Check out this impressive video.

Categories
Furniture/Cabinet Making Wood Carving Woodturning

The Janka Hardness Test

The hardness of a timber is measured by the Janka hardness test. This test measures the force required to embed an 11.28mm (0.444 in) steel ball to half its depth into wood. The Janka hardness test is the industry standard for determining the ability of a particular timber species to withstand denting and wear.
In Australia, Janka results are displayed in either newtons (N) or kilonewtons (kN).

Species Janka Rating (kN)
American Oak 6.0
Australian Beech 7.5
Bamboo (horizontal) 5.87
Bamboo (vertical) 6.58
Bamboo (strand woven) 16.10
Blackbutt 9.1
Brazilian Walnut 16.37
Brushbox 9.5
Cypress Pine 6.1
Flooded / Rose Gum 7.5
Forest Reds 9.1
Ironbark 14.0
Grey Box 15.0
Jarrah 8.5
Karri 9.0
Merbau 8.56
Messmate 7.1
New England Oak 6.1
Northern Beech 7.5
Red Mahogany 12.0
Ribbon Gum 6.1
Spotted Gum 11.0
Stringybark 8.1
Sydney Blue Gum 9.01
Tallowwood 8.6
Tasmanian Oak 5.5
Turpentine 12.0
Victorian Ash 4.49

Have a query?

Contact Form

Located

33A Sefton Rd Thornleigh NSW 2120