PO Box 52096, Berea 4007, South Africa
CHAIRMAN’S CHIRP congratulated on keeping five lathes going almost
continuously for four days.
I know the Cape Town chaps do a lot of demonstrating to
Preparations are well underway for Congress after rather a the public, but unless we hear about it, we cannot share
slow start when we had difficulty finding a suitable venue these experiences with the members of AWSA. This is a
that we could afford in Durban. We finally settled on pity!
Glenwood High School as it is able to provide very similar
facilities to those we enjoyed at Hudson Park in East We have had good response to our requests for articles and
London. Certain facilities may be better, like a fully Brian is able to publish some fantastic ones in this issue of
airconditioned plenary room for the large demonstrations,
but certain other aspects may prove less convenient, like all Turnaround. We are also now receiving more local
demo rooms being on the first floor. There is a lift!!! Cheap Guild Newsletters. I really encourage all guilds/
dormitory accommodation is available with food, and the associations to produce their own Newsletters, however
school caterers will be providing all our meals during short or simple they may be, as from our own experience
Congress in their large tuck shop. Their main hall is large here in Durban, good communication with our members
and we can hold the Instant Gallery, AGM, auction etc all has been one of the main strengths that has doubled our
in this venue. In the very near future Application Forms to membership over the last five years. Please also send your
attend will be distributed. Newsletters to other local Editors and Chairmen. Use Email
and it costs nothing extra.
Our second difficulty has been to find an overseas turner
who is able to attend Congress and tour the country. It John Mills – Chairman
appears that August in the UK is a very busy time for them
and the two that we have approached so far, Mark Hancock
and Laura Ponting are fully booked. Mark cannot even
come next year. We will try for a bit longer, but the bottom
line is that we may not have a visiting turner for Congress.
The good news is that both Reg Sherwin, whom many of
you already know, and a lesser known to us German turner
Johannes Volmer, who seems to be one of the fathers of
oval turning techniques, both want to visit SA at their own
expense and tour around meeting local turners and giving
demonstrations. Reg may well come during November and
Johannes next year. I have indicated to both of them that we
would be happy to host them and provide accommodation
and local transport.
If we do not have a visiting turner at Congress we hope to John Mills’ bowl blank pile
have a couple of other surprises for you all, which we think (Actually logs for feeding boilers at a sugar mill in
you will enjoy!!! Mozambique. They use wood to get the boilers started and
then burn bagasse – the cane residue. Mostly fever tree but
I HOPE YOU ARE ALL PREPARING SOME some very turnable material also)
WONDERFUL PIECES FOR THE INSTANT GALLERY
Dates : 9, 10 ,11 August
Registration : Thurs 8 Aug pm and Fri 9 th am.
In the last Turnaround I mentioned that Schalk was
Place : Glenwood High School, Mc Donald Rd.
working at getting AWSA involved in Hobby-X and I am
delighted to see from the two articles published that it was a
Cost : TBA – Dependent on overseas turner
great success and excellent publicity for our Association.
The Witwatersrand and Pretoria clubs are to be
HOBBY-X edge turning, square platters and the secrets of captive ring
turning particularly fascinated people.
Reported by Trevor Pope - Wits Woodworkers
Association Apart from the fact that it was great fun entertaining the
huge crowd, quite a number of new members were
The turners put on a most impressive display, under recruited for the Pretoria Woodworking Association,
the auspices of the Association of Wood-turners of including at least two from the fairer sex. A father and
South Africa. There were five lathes that were almost daughter are presently undergoing basic turning tuition
constantly in use, demonstrating a variety of from At Smit.
techniques. Two more people were on duty to answer
A retired gentleman from Kenton- on-Sea, on a visit to his
questions from the visitors in front of the display area family in Pretoria, saw the turning demonstrations at the
where a variety of turned work was on display, Hobby X. He made an appointment the following week
showing the quality of work done in the club. The with At Smit to gather more information on lathes and
show ran over 4 days (07th to 10th March at the MTN turning aspects. He was so impressed and enthusiastic with
Sundome) from 09h00 to 19h00. A fantastic effort what he saw that he left Pretoria for home with a brand new
was made by the Jo‟burg turners with help from At swivel head lathe in the back of his car. He undertook to
Smit, Roger Courtney and Louw Trichard from the contact his nearest wood tuning association/guild for
Pretoria club. The stand generated considerable further guidance and help.
interest from the public all to promote the craft. As a promotional exercise for woodturning, the Hobby X
demonstrations were definitely a great success
Toyota donated twenty shirts for the demonstrators, so
we were able to put on a uniform display that made it
clear to the public who was manning the stand.
Thanks to Schalk for his particular effort in planning
and organising the overall display and to Toyota for
their support! Thanks also to Hardware Center for
providing some of the lathes for the demos, as well as
arranging the space for the demos. (The bill is in the
post for commission from all the referrals we made on
enquiries we received about lathes, tools, etc.)
Hobby- X – A general view of the exhibition
I‟m sure you enjoyed Izak‟s article in the January
issue. Here is the second in the series.
WOODS I HAD A TURN WITH…PART II
Last month I mentioned teak (Tectona grandis) as one of
Hobby-X demo – Schalk avn Niekerk shows them the woods that kiaat is often confused with. That reminded
how me of an article I read many years ago in a Woodworker
magazine. It really taxed my patience to dig around in my
Hobby X “archives”, and, Woodworker, November 118\982 had it
all!! I am reproducing the article verbatim in its entirety
A report from the Pretoria participants with due recognition to Woodworker magazine and the
author of the article, the then timber expert of the magazine
Seven wood turners from Pretoria from the Pretoria Bill Brown.
Woodworking Association combined forces with the
turners from Johannesburg to put up a continuous turning A Tale of Teak……
demonstration on at least four lathes for the four day What does teak, that most dependable of woods, have in
duration of the Hobby X over the period 7 – 8 March 2002. common with the musical stage? Quite a lot, according to
our timber expert, Bill Brown, who here tells the tale of the
King of Siam, Anna and teak.
The members participating enjoyed the experience (and
admiration from the public) as well as the opportunity to True teak, the product of Tectona grandis, is a wood
get some training practice. Many and varied questions renowned for its durability and stability in service, but it is
from the public were answered. Aspects such as natural outstanding in several other aspects. At one time it was the
only timber classed A1 at Lloyds, Kipling wrote poems in years Chinese merchants had exploited the teak from these
connection with the wood, a war was fought over it, and a forests, and one such organisation, Kim Sing Lee, sold out
famous musical has teak connections. to BBTCL, thus allowing them to get a toe-hold in Siam.
Teak is highly resistant to fire, both as wood and as a Anna Harriette Crawford was born in Caernarvon, north
growing tree, in fact, it is said that forest fires improve the Wales, in 1834 and when she was six years old her parents
quality of young teak trees, and it is certainly true that fire sailed for India. Her father was an army captain whose
aids the germination of teak seeds. The seeds are enclosed regiment had been ordered to reinforce troops there in the
in a husk which needs to be removed in order to assist face of impending war. A year later her father was killed.
germination. A forest fire does this without harm to the
seed so that new seedlings encourage natural regeneration. When Anna was 15 her mother married again but the
stepfather and Anna did not get on and when she later met
Teak is highly resistant to termite (white ant) attack, and and fell in love with a young British army major, Thomas
because of its short fibres, tends to break under impact Louis Leonowens, there was much domestic strife
without splintering. It was for this reason it was used culminating in Anna marrying her “own Leon” in 1851.
extensively for railway carriage construction and for The break with her stepfather was now complete, but
backing armour plating in warships, thereby reducing unfortunately the stepfather was the executor of the estate
accidental potential damage to humans. her father had left her, in fact that was to affect her later
It is the only tropical hardwood tree that is commercially
ring-girdled prior to felling, and the only one whose Anna had an unfortunate marriage. She had lost her first
extraction from the forest developed around the use of two children through illness very early. There were two
elephants. It is said a well-trained animal could haul about other children, Avis, born in 1854 and Louis Thomas born a
150 logs, each of about a ton, from forest to riverside in a year later. In 1857 the Indian Mutiny broke out and when it
season. subsided, Anna found she had not only lost her friends and
relatives but also her fortune.
Ring-girdling prevents the flow of sap from the roots to the
crown of the tree and so allows excess moisture to In 1856 Leon was ordered to Singapore and there the
evaporate through the leaves. In other words the tree family lived, but in 1858 Leon died of sunstroke brought on
partially seasons at stump, enabling the felled logs to float by carrying out a tiger hunt during the heat of the day –
down river to the sawmills. Girdling is done by cutting into typical of mad dogs and Englishmen. Anna‟s stepfather
the bark with an axe, at about breast height, the cut going had, in the meantime obtained possession of the old house
right through the sapwood and completely circling the bole. in Caernarvon and now she had nothing beyond the two
It is done annually, and girdled trees are allowed to stand children.
for two or three years before felling.
I wonder how many people who have seen that delightful To earn a living, Anna opened a school for officers‟
musical The King and I realise the element of truth that is in children and this came to the notice of Tan Kim Ching, the
the story. Or the fact that Anna, the governess in the story, Siamese consul of Singapore, who had been instructed by
not only existed, but represents a direct connection with the the King of Siam to secure and English governess for the
teak trade of London extending back from the present time royal children. After protracted negotiations, Anna
to the mid-19th century, when Thailand was Siam. received a letter from the king himself offering her the job,
The teak trade actually started in India and Burma, one of and it is from this stage onwards that the basis of the play
the principal British organisations being the Bombay and film developed with, of course, a certain amount of
Burma Trading Corporation Ltd, whose shipping mark poetic licence.
BBTCL was literally the only one seen on teak when I was Among the pupils none attracted Anna so much as Prince
a boy. It was an extremely powerful company, but there Chulalonkom and his sister Princess Chanthara Monthon.
was a fly in the ointment, so to speak. In fact there were Both were exceptionally bright and being of about the same
two flies: the corrupt King Thebaw of Burma and the age as Anna‟s children, became firm friends.
French consul of the time, one M. Haas, whose ambition it
was to oust the British from Burma in connivance with the
king. A treaty was negotiated between France and Burma In 1867 Anna became ill and against the king‟s wishes went
under which the French would set up a state bank, take over first to Ireland and the to New York to try to recuperate,
the ruby mines, and exploit the teak forests of Upper taking Avis and Louis with her. A year later, King
Burma. In the event, the treaty signed by King Thebaw fell Somdetch Paraminder Maha Mongkut was dead and was
into British hands and the Foreign Secretary, Lord succeeded by his son Prince Chulalongkom. Anna never
Salisbury, took appropriate action typical of the time: returned to Siam and although the king remembered her
within a couple of months am expeditionary force was sent and Louis generously in his will, neither received the
to Burma and the ensuing campaign led Kipling to write the inheritance. The executors stopped it.
The new king was extremely progressive and pro-western;
This third Burmese War was quickly over and was he had his sons educated at English public schools and
probably the only war to be fought on behalf of the timber abolished slavery, established telephone and telegraph
trade. The BBTCL eventually recovered and expanded, services, constructed roads, hospitals and so on, carried out
although a number of its staff were killed by the Burmese. reforms of law and taxation.
The best teak forests in Siam were in the territories of the Louis Leonowens was by now very restless, he went to
Laos states of Upper Siam, and although independent, they Australia, but in 18822 he returned to Siam where his
acknowledged the King of Siam as suzerain. For many friend the king made him an officer in the army. It was
perhaps inevitable that Louis became a man of considerable progress to be updated whenever new information and
influence wit the king and eventually he set up in the teak experience become available. My knowledge of the
trade as Leonowens and Company of Bangkok. materials and processes involved is very limited indeed,
assembled from scraps of information from various books
King Chulalongkom died in 1910 and in more recent year, and articles on blacksmithing, knife making and model
Leonowens became a subsidiary of a prominent firm of engineering. I therefore welcome any feedback from
timber importers and are still represented in what is now an anyone who has any comment or anything to add.
international group of timber companies based in London.
As an individual much caught up in romanticism of timber This article describes the process of making a gouge in the
and trees, I like to believe that it was Anna‟s work at the following steps:
court f Siam that led to the young prince adopting the Basic metallurgy (the minimum we need to know
western idea of s and for providing the opportunity for about tool steels, simplified to the extreme)
young Louis to exploit the teak forests. As the song says, Selecting suitable steel
“Getting to know you. Getting to know all about you”, Grinding a flute
which being interpreted could mean „It‟s not what you Hardening the steel to its maximum possible hardness
know, but who you know, that counts‟. (which is too hard to be useful)
xxxxxxxxxxxxxxxx Tempering (softening it very slightly to a practical
like Lebanon, cedar, teak is one of the oldest trade timbers
of the world, and was used in Babylon and Egypt 4000
The finished product is by no means the ultimate gouge.
years ago – B. Hausen: Woods Injurious to Human Health
You will not be throwing out your Sorbys or Titanium
– p. 117.
coated tools in favour of these, but they work well enough
As seen from the above, teak is indigenous to the East and to be in everyday use filling the gaps in your range of
more specifically to India, Burma, Thailand, Indo-China gouges. If, for example, you already have a high quality
and Java, and has been planted in Africa and the West 12mm HSS bowl gouge, try supplementing it with a 6mm
Indies. According to W.A. Lincoln – World Woods in gouge for detail work, a 10mm gouge with a long pointed
Colour – p. 268, the true teak of Burma is a uniform bevel for delicate finishing cuts, and a 16 or 18mm heavy
golden-brown colour without markings, but most other teak gouge with a very steep blunt bevel for working across the
is rich brown with darker chocolate-brown markings. bottom inside deep bowls.
Indian teak is wavy grained and mottled, but generally
straight to wavy grained, coarse textured, uneven, oily to The main advantage of home-made gouges is that they cost
the touch, and sometimes with a white glistening deposit. next to nothing. This means you can make as many as you
The average weight is 650kg/cub. M. It works well but has like and modify flute shapes, bevel angles and grinds to
a severe blunting effect on cutting tools. Stains well and your heart‟s content because they are almost expendable.
takes a satisfactory finish, especially on an oil finish. The main disadvantage is that you will almost certainly
have to sharpen more often, particularly on hard, abrasive
Warning: Fine machine dust is a skin irritant. Teak has woods where they are unlikely to hold an edge as well as
long been known for its toxic properties. The first case of High Speed Steel. More sharpening means they won‟t last
dermatitis was reported in 1896, while the first full as long, but who cares? On wet wood they perform well,
description of a case of contact allergy was given in 1905. you may not even notice any difference between these and
Chemical investigations revealed two sensitisers causing your expensive gouges. The other limitation is that they are
allergic contact dermatitis. vulnerable to heat (the section on tempering explains why).
Next month: How is the hardness of wood determined? This does mean you need to keep them cool while
What have Ocotea Bullata, Celtis africana and Phoebe sharpening, particularly with smaller tools. Just dip them in
porosa in common water frequently while sharpening and don‟t ever let the tip
get hot enough to burn your fingers.
@@@@@@@@@@@@@@@@@@@@@@@@@ (VERY) BASIC METALLURGY
MAKING YOUR OWN BOWL To make cutting tools we need steel which can be hardened
sufficiently to hold a durable edge. Ordinary steel, usually
GOUGES - By Grant Marshall - Knysna called Mild Steel can‟t be hardened because it lacks
sufficient carbon. Our focus is therefore on Carbon Steel
With the current high cost of imported tools these days, (also called High Carbon Steel or Tool Steel) which
buying a range of different sizes of gouges is very contains between 0.8% and 1.2% carbon. For now we can
expensive and having additional specialised gouges with forget about High Speed Steel, I‟ll explain why later.
different bevel angles for special cuts is a luxury few can
afford. While most turners are happy to make scrapers or When heated to above its transformation temperature
thin parting tools, most probably imagine that bowl gouges (“Cherry Red” in blacksmith‟s terms, or about 800 degrees
would be too difficult to make in a home workshop. The C), steel has an affinity for carbon, combining with it to
fact is that with simple equipment and a basic grasp of the form a carbon-iron compound called iron carbide. Below
principles, making a usable gouge is not difficult at all. that temperature it doesn‟t like carbon. Allowing it to cool
very slowly from red hot will cause it to dissociate into its
Here follows a fairly detailed account of my own constituent components of iron and carbon. This process is
explorations into the field of home-made gouges. I am still called annealing and will cause a softening of the steel.
learning as I go so this article is very much a work in Cooling it very rapidly, on the other hand, (by quenching it
in oil or water) gives it no time to separate and the carbon Here are some examples:
atoms get trapped inside the iron crystal structure. This Any round spring steel
yields a very hard and very brittle steel measuring 65 - 66 Torsion Bars and anti Roll Bars from cars
on the Rockwell C hardness scale. Unfortunately this too suspension
hard to be useful because the micro edge chips off instantly Torsion spring rods used in some car boots
in use. McPherson strut or shock absorber shaft
“W”- shaped camp bed leg
To be useful we need to temper it, in other words to soften Bakkie tonneau cover support rod
it very slightly by heating it just enough to turn a precise Any round tool steel
amount of the very hard stuff back into carbon and iron
which will make it more flexible and tougher. How hot we
make it determines how much turns back. Too much heat
causes too much softening and the hardness is lost. Note that some things like shafts and tools may have been
casehardened, which means the outside is hard but the
That‟s pretty much all we need to know about this vast and middle isn‟t. For gouges we need to harden all the way
complex field. To summarize: We take a piece of carbon through because our cutting edge is located somewhere
steel, heat it red hot and quench it very quickly to harden it near the middle. Steel used in things like garden tools and
as much as possible. Then in a process called tempering we crowbars may not contain enough carbon to be hardened
soften it just a little to achieve a durable hardness. enough.
The exact temperatures involved vary depending on the To test the suitability of steel on the spot try punching,
precise content of the steel, but for our purposes filing or hacksawing it, you‟ll soon know if it is hard
transformation temperature is around 780 - 820 degrees C enough because the file will skate off it without cutting it.
(cherry red when viewed in your workshop in daylight). Back in your workshop you can use a spark test to get an
Conveniently for us, this is also exactly the temperature at idea of the composition of the steel. Touch a piece of mild
which carbon steel becomes non magnetic, so when a steel on your bench grinder so you get a stream of sparks
magnet won‟t stick to your red hot gouge you‟re at the right out into space. Take a good look at the sparks and compare
temperature. For tempering we use much lower them to the sparks you get from the tip of a file or an allen
temperatures, around 150 to 350 degrees C and here we can key (both are high carbon steel). Notice how carbon steel
make use of the colours of the oxides released onto the
produces a lot more sparks than mild steel and they are
surface during heating. (See the table of temperatures and
colours.) We‟ve all seen a piece of clean shiny steel change much finer and whiter and they explode much more in
colour as it is heated, going from pale yellow, through flight. The more little explosions, the more carbon in the
straw and brown to purple to blue (as novice turners we steel. Basically, any steel you want to use for tool making
may have seen the tips of our gouges go those same pretty must make sparks exactly like the allen key makes. Just for
colours during overzealous sharpening). That first pale fun check out the sparks from the back end of a drill bit or
yellow appears at 200 and that‟s about right to temper the from your best gouge (high speed steel). HSS produces
steel to the hardness we want (about 62 Rockwell C). The very few sparks, they are deep red in colour, they don‟t
purples and blues mean a higher temp has been reached and explode at all and they fly in curving paths.
the steel has been softened too much for our purpose
Okay, so now you have a suitable length of carbon steel rod
MATERIALS and you want to make a gouge.
There is no shortage of sources of carbon steel suitable for FLUTING
tool making. The ideal would be to buy a rod of the right
diameter from a specialist steel supplier. The advantage Start with an over-length piece so if you really make a mess
here is you get a description of its exact composition and of it you can cut the end off and try again. You can anneal
you get precise instructions for hardening and tempering so (soften) the section you want to work on by heating it to red
there‟s no guessing. Whether this will yield a better tool
hot and letting it cool very slowly over a period of several
given our crude home-workshop methods is debatable.
hours. Poking it into a braai and then leaving it there while
Different steel manufacturers will have different names for
their steels but you will need to ask for a cold work carbon the fire burns itself out is ideal. This will make it a bit
tool steel that can be hardened and tempered in a home easier to work but isn‟t really necessary. Initially you
workshop. Bohler Steel makes one called “K460”, other should try to copy the flute shape and proportions of a good
names are “Oil hardening drill rod”, “O1”, BO1”, and gouge until you know enough to experiment with different
“Silver steel”. These steels may have small amounts of shapes. A good basic shape would be somewhere between a
other alloys added to them to give them particular U and a V with the bottom of the flute a bit lower than
Small tools are easier to make than larger ones at first. I
But we don‟t need to buy fancy steel to make a usable find it best to keep the flute fairly short for several reasons.
gouge. There‟s plenty of useful junk steel available. Almost Firstly the tool is stiffer because more of its length is solid.
any steel harder than mild steel will probably work, and It is safer because only the fluted end is hardened and you
anything that was springy in its previous life will do fine. A are less likely to snap it in use. Lastly a short flute seems to
motor stripper or a junk shop should yield plenty of eject shavings better and the stream of chips doesn‟t hit
different sizes. your hand. You can always lengthen the flute later and
perhaps improve on the profile of it when you do.
habit of bursting into flame unless the tool is completely
Start by drawing lines on with a felt tip pen to indicate the submerged when you quench it. This is where the heavy
top edges of the flute. Flatten the top with an angle grinder wire handle is useful. Work outside and be prepared for a
down to the two lines. Start cutting the flute from the tip fire anyway. If you buy the steel for the tool the
(which is still expendable). You can use a cutting disc first manufacturer should tell you what liquid to use for
to make a slot and then switch to a thicker grinding disc to quenching. Some refinements to the process are to add
widen it and shape it, but I‟ve done the whole thing with about 8 or 9% salt to the water to raise it‟s boiling point, or
one or the other depending on the size of the flute. It‟s a to pour a 4cm layer of oil onto the water so the tool passes
messy process, so I‟ve taken to working outside on my through the oil first. Warming the oil to about 60 degrees
driveway with the tool clamped to a stepladder. Use a aparrently helps because it thins it and you get better
protective face-shield so you can get in really close to see contact with the metal.
what‟s happening. Beware of the spark stream, I set myself
alight once. Stop often and use a felt tip pen to highlight The exact hardness you obtain depends on the actual steel,
spots that need more work or that are complete and mustn‟t but it will be somewhere around 64 - 66 Rockwell C. As it
go any deeper. I find it easiest to do a short section at a time is it‟s pretty useless, the edge will be brittle and will blunt
and get it perfect before going further up the length. quickly. You can test it for hardness by filing it or punching
it carefully with a cold chisel. Try it at the tip and further
I hang onto my old angle grinder disks because some have back on the shaft. Your fluted section should be much
worn to a profile that works well for this purpose. It‟s good harder than the raw material, and a lot harder than the file
to try to work in both directions while shaping the flute, but or cold chisel.
absolute symmetry isn‟t essential. There could even be
advantages to an asymmetrical flute, who knows? It‟s After hardening the fluted section will be a dull black.
important to avoid grooves or ridges in the profile of the Polish the outside to a bright silver with a strip of sanding
flute because these will appear as notches or points in your belt or water paper. Now you need to grind away the
cutting edge. You will need to grind at least 0.5mm of steel surface metal inside the flute because it lost some carbon
off the inside of the flute after hardening, so don‟t go too during the heating process and we need to get to good fresh
deep, particularly on small tools. steel about 0.5mm deeper. If it was heated I a charcoal fire
this will be less of a problem, but regrind anyway just to be
When you‟re happy with the flute you can grind off some safe. Grind carefully so as not to overheat the steel. The
of the tip to begin forming the bevel but don‟t sharpen it too surface of the flute forms your cutting edge so it‟s worth
much yet or the thin edge will overheat during hardening.. trying to get it perfectly smooth and even. Avoid
overheating it while you grind, dip it in water often to keep
HARDENING it cool. If you roll up a sheet of water paper and polish the
flute your tool will take a better edge and eject shavings
Hold the tool with tongs or wrap some heavy wire around it better.
so you can hold it completely submerged in the quench
medium while agitating it. For small tools up to about 8 or TEMPERING
10mm dia you can try heating with a plumber‟s butane
blowtorch, but for larger tools you will probably need an Once you have it clean and shiny there are 2 ways of
oxyacetylene torch to provide sufficient heat. You might tempering the tool. The first method is easiest to control.
even be able to approach your local exhaust repair shop and Simply put the tool in your kitchen oven for an hour at 200
use their torch. If that‟s not available you could try rigging degrees C. When you take it out it should be a uniform pale
up some sort of blower into a charcoal braai to form a yellow colour and its hardness should now be about 61 or
makeshift forge. Heat the fluted section slowly to red, 62 Rockwell C, but this is not absolute, it varies with the
applying the heat from underneath to avoid overheating the alloy/carbon content of the steel and the accuracy of the
thin edges of the flute. Test it with a magnet as soon as it oven thermometer. An exact hardness is difficult to achieve
begins to glow, and test frequently when you think you are without specialist equipment so be prepared to experiment a
close. When the magnet doesn‟t stick you are at around 800 little. Treat the colours and temperatures as relative to each
degrees, note the colour. Remember that “cherry red” looks other for that particular tool/steel. If a tool tempered to very
different in different light conditions. You can go about 50 pale yellow doesn‟t appear to be holding an edge well it
degrees more to be safe, but hotter than that isn‟t a good could still be too brittle, try tempering it again at a slightly
idea. Keep it at that temperature for a minute or two trying higher temperature to darker yellow.
to keep the whole thing an even colour. It‟s not necessary to
harden further back than the flute itself. Bear in mind that Do remember to remove every last trace of quenching oil
the magnet only gives you an accurate indication while the from the tool before putting it in your oven. If you don‟t
temperature of the tool is rising. If you accidentally you‟ll have to live with the smell for a long time. It‟s also
overheat it and then test it while it is cooling you don‟t get worth putting a temporary handle on a tool at first so you
the same result. can test it, or at least hot glue it into the handle so you can
get it out if it needs further heat treatment.
Now plunge it quickly into a large container of water or oil
and agitate it vigorously (waggling it is apparently better The second method is quicker but consistent results are
than stirring it), trying to cool the whole thing as quickly (in difficult to achieve. Heat the tool slowly and gently with a
less than a second) and as evenly as possible. Uneven soft flame from a blowtorch along the fluted part, as evenly
cooling will cause warping and slow cooling will cause as possible and avoiding the very tip (which will overheat
hardness problems. Water is easy and clean but it can cause easily). When the colour changes to a pale yellow and
cracks to appear particularly in larger tools. Oil (such as old before it goes a darker straw or purple, dunk it quickly in
motor oil) works, but it‟s messy, smelly and has a nasty water to stop any further softening. Note that any variations
in colour will cause variations in hardness in the finished steel, shape it and send it away for hardening by
tool. I prefer to combine both methods, getting a fairly professionals.
precise hardness in the fluted section with the oven, then
softening the rest of the body of the tool a little more with a OTHER TOOLS
flame. I would rather my tools bend in use than snap.
These same principles can be applied to other tools. Old
With an understanding of the tempering process it‟s easy to files are a good source of very high carbon steel but as files
see why you can easily ruin a carbon steel tool by they are dangerously brittle. They can be annealed in a
overheating it on the grinder while sharpening. Regular charcoal fire and then cut with a hacksaw or drilled before
dipping in water will prevent overheating while grinding. If hardening and tempering. Or they can be placed in the oven
it makes a hissing sound when you dip it, it was already and tempered for use as scrapers. If you are going to use the
over 100 degrees and the very edge could be very much whole file as a scraper, it‟s a good idea to soften the main
hotter. At 250 it is ruined. Temperature, oxidation colour body more than the tip to lessen the chance of it snapping in
and hardness are all linked. Once the steel at the tip goes use. Bluing the body with a blowtorch should do the trick.
dark blue its hardness has dropped to about 50 Rockwell C And choose a fine file so there‟s less to grind off to make it
and rendered it useless. The soft steel must be ground away smooth.
or the tool can be salvaged by re-hardening and re- HSS planer blades can be cut up and slotted with an angle-
tempering. grinder for use as scraper tips. Because of its tungsten
content, even if the steel goes blue it shouldn‟t affect its
ability to hold an edge.
HIGH SPEED STEEL
High speed steel is a tool steel that retains its hardness even
at very high working temperatures because it has about 6%
tungsten added to it. In use it isn‟t necessarily harder then
carbon steel, it just doesn‟t lose hardness at around 200 deg
C like carbon steel does, in fact heating it to around 550
deg has no effect on it. And its transformation temperature
isn‟t 800 degrees either, it‟s over 1200 degrees. It‟s simply
not feasible to harden and temper it in a home workshop, it
requires far higher temperatures, more accurate temperature
control and a reducing atmosphere to protect the steel from
oxidation during heating.
If you really want to make HSS tools it is better to buy the The stages of fluting the gouge
HEAT TREATMENT TEMPERATURES FOR CARBON STEEL
Temperature Colour - Glowing Steel
2350 1288 Dazzling White
2200 1204 White
1975 1079 Light Yellow
1825 996 Lemon
1725 941 Orange
1650 899 Salmon and Scaling
1550 843 Bright Red and Scaling
1375 746 Cherry Red
1250 677 Medium Cherry Red
1075 579 Dark Cherry Red
1050 566 Blood Red
900 482 Faint red (GLOW)
Temperature Colour - Polished Steel HARDNESS TYPICAL APPLICATIONS
750 400 Grey
610 321 Pale blue 53Rc
567 297 Bright Blue 55Rc Cheap Kitchen knives
550 287 Dark Blue 56Rc Springs
531 277 Purple 57Rc Cold Chisels and punches
509 265 Brown & Purple 58Rc
491 255 Brown 59Rc Taps and Scribers
469 243 Gold Yellow/Straw 60Rc
428 220 Pale Yellow 61Rc
400 200 Very Pale Yellow 62Rc Woodturning tools
SOME THOUGHTS ON DESIGN
Compiled by Andrew Stevens
'Design is the process of making things better for people.' - Richard Seymour
'Design is not just about how something looks, but how it works.' - James Dyson
'A plan for arranging elements in such a way as to best accomplish a particular purpose.' - Charles Eames
'If you can't explain it on the phone, then it's probably not worth doing.' - Bob Gill
‘Design is not all a matter of problem-solving, neither is it all a matter of art. It is both. The two parts of it are
inseparable.’ - David Pye
'After the colours have faded and the grain patterns have become obscure, only the form of a bowl will ensure its
survival as a desirable object. A bowl of spectacular colour or grain will draw gasps of admiration regardless of its
shape, but this is no indication of how good a bowl it is. It is the timber that is being praised, not the bowl. While it is
all very well to use grain and colour to stunning effect, these characteristics will never outlast the shape - the most
important aspect of a bowl.
Form is all too often regarded in visual terms only. But because bowls are also handled, the tactile qualities are just as
important.' - Richard Raffan Turned-Bowl Design, p40.
'Unstructured creation, freed of a grounding in classical rules, most often results in cerebral popcorn. It is usually also
self-indulgent, appealing only to the creator - a case of beauty being only in the eye of the one beholder!'
Hugh O'Neill: Woodturning, A guide to Advanced Techniques, p.54
'When you are learning the skills involved in woodturning, improving your techniques is important for your sense of achievement
and satisfaction. Mastery of the techniques is essential if you are to create good work, and without a high degree of skill, your work
will be limited. However, command of technique should not be seen as an end in itself; it is simply the means by which you can
produce a beautiful bowl. Form is paramount.'
Bert Marsh,Woodturner, p24
Our appeal for news and articles from around the country and Louw Trichardt whose work is published here.
has borne fruit. Not a bumper crop but with nurturing the Also to Graham Ward and Allan Ferguson whose articles
seeds arising from your resent efforts are likely to produce will be published in a future Turnaround
more prolific yields. Thanks also to Elliot Murray for his very detailed report on
On behalf of the members, many thanks to those who the AWSA EL 2001 Congress. This is being applied as a
contributed. very useful set of guidelines for the Durban Congress
I have more than I can publish in this edition so the surplus committee.
will be carried over the next. I now get newsletters from four of the eight AWSA
Thanks to the following for their effforts. chapters. They are :
Izak Cronje, Grant Marshall, Andrew Stevens, Trevor Pope,
REGIONAL NEWSLETTER CONTACTS
REGION CONTACT PHONE e- MAIL
Gauteng (Witwatersrand) Trevor Pope 011 622 7018 Tpope@iafrica.com
Western Cape Gigi Laidler 021 7977755 Laidler@nbict.nbi.ac.za
East London Nigel Waters 043 735 4669 Nigel.firstname.lastname@example.org
Pretoria Louw Trichardt 012-653 1874 Louwmarie@icon.co.za
Durban Brian Kitching 031-560 1497 Brian.email@example.com
To spread our news far and wide, I would like you all to e-mail your newsletter to all the other regions, even if only to
the secretary or area representatives for them to distribute to their members.
See the January Turnaroud for more contact details. Keep those articles rolling. Cheers, Brian