Dr Dillner's health dilemmas: will a mouthguard stop me grinding my teeth?

Teeth grinding is not only annoying but fairly common. It's a condition in which you grind or gnash your teeth, especially in your sleep. It may not cause any problems but can give you headaches, a sore face and jaw pain. Persistent teeth grinding may damage the joints in the jaw, which will make it painful to yawn or chew.

No one knows what causes teeth-grinding. Children do it more often than adults, possibly because their baby teeth are smoother and more amenable to grinding. It is common if you are stressed or anxious. Occasionally it can be due to your upper and lower teeth not being aligned properly or because of medications, including some antidepressants.

There is no magic cure, but mouthguards are often recommended to protect the teeth at night. Think sports guard for when you're playing rugby or hockey and you'll get the look. But do they work or is there anything just as effective but less intrusive?

"Mouthguards work well but they are best fitted professionally," says Damien Walmsley, scientific adviser to the British Dental Association. "You should see your dentist, who will take an impression and usually fit one on the top teeth. They're plastic and can be soft, although people can chew through them, in which case they'll need a harder guard. If you get one from the chemist and mould it yourself it won't fit well enough."

They work by separating the teeth and preventing grinding. You can then see if you're still grinding by checking the wear and tear on the guard. They can take some time to get used to but but they stop your face and jaw aching and reduce the likelihood of you breaking your teeth. You only have to wear the guard at night but you may need to continually use it if your grinding has become an intractable habit.

If you don't fancy a mouthguard and suspect stress is making you grind your teeth, you can try relaxation techniques and meditation. You should rest your tongue upwards, with your teeth apart and lips closed, which reduces the tendency to stiffen your jaw and grind. Children who do it can be helped by getting them to relax before they go to sleep with a bath and story.

It's worth going to the dentist if you grind your teeth, not only for a fitted guard but to check your teeth are not misaligned. Sometimes reshaping the surface of teeth will help. But if it's an ongoing problem, forget the cosmetic drawbacks and get yourself a mouthguard.

Forteq counts on precision

Swiss company Forteq, with its headquarters in Nidau, designs, moulds and assembles precision plastic gear and transmission and mechatronic devices used in automotive, consumer electronics and healthcare industries.

Its expertise in precision moulding an asthma inhaler counter was explained by Dr Joachim Franke, Forteq Healthcare's managing director, at an open house event held in September at the Wiehe, Germany plant of Sumitomo Demag (SHI Demag).

In 2010, the inhaler accounted for around 80% of the production value in Nidau. The plant has 15 injection moulding machines (mainly SHI Demag machines) with 60-125 tonnes clamping forces, a 1,600m2 cleanroom, automatic assembly, printing machines and six Wittmann robotic systems.

Franke spoke in Wiehe about an aerosol asthmatic pressurised Metered Dose Inhaler (pMDI) counter, consisting of 14 parts - 10 of plastic and the rest metal springs. Numerical counter wheels and gears are moulded in POM, the housing in PP and the small viewing window in PMMA. Insys laser equipment writes numbers at 700 characters/min on the wheels, which are made in POM containing laser sensitive colour-change pigments.

Shot weight of the smallest plastic part is 0.73g, part weight 0.023g, requiring mould removal by Wittmann W721 and W723 linear robots with vacuum grippers.

Plastic part dimensions range from 3.5 x 3.55mm up to 22.35 x 16.75mm for the PP housing. Forteq moulds down to precision of 0.005mm, moulding small 0.5mm holes in some parts.

According to Franke, absolute precision calls for absolute process management in, for example, ejection control. Close tolerances ensure sufficiently low friction in the counter drive system, and an absolute fail-pass zero defect policy system is applied to ensure each "firing" is counted.

Forteq uses 32-cavity moulds with hot runners to ensure fastest possible cycle times for large production volumes of "millions per month", while keeping the number of moulding machines to a minimum. The machines are required to have fast parallel movements. There should also be "minimal use of expensive medical approval plastics and regranulate is not allowed", Franke observed.

As the machines are used in an ISO 7 cleanroom environment, they have to have low particle emissions and ease of maintenance, along with fast and easy changeover of tools and the 14mm screws.

Forteq carried out batch-to-batch variation studies using hydraulic, hybrid and all-electric drive machines from different companies. The machines used identical moulding parameters and the same 4-cavity hot runner trial mould.

When moulding a POM numerical wheel, hydraulic machines produced wheel thickness varying from 2.80mm to almost 2.90mm, while hybrid machines achieved 2.84mm to 2.87mm.

Repeatability tests on a production tool looked at drum wheel and ratchet pawl parts on hybrid and all-electric machines, using the same process settings and cavity. Results showed drum wheel diameter of 7.875-7.900mm using the hybrid drive and 7.91-7.92mm using the electric drive. Cycle time fell from 11.5s for the hybrid drive to 9.5s for the all-electric drive.

Tests were also done on a 22.35mm nominal diameter cap, which again showed less deviation with the electric drive, and with cycle time reduced from 11s to 10.2s.

The ratchet pawl inner diameter deviated from around 1.465mm to almost 1.51mm on hybrid machinery, compared with 1.485mm to just under 1.51mm with the electric drive, and cycle time fell from 7.6s to 6s. Process optimisation cut cycle time further to 4.2s, along with even closer dimensional tolerance .

Franke said: "Testing all part combinations is not economically justifiable, yet patient safety has to be ensured. Therefore, maintenance of tightest possible tolerances is absolutely essential."

Weapons in cells: jailbreak bid for Moyo?

Was slippery awaiting-trial prisoner Bongani Moyo trying to escape again? This is the question the authorities are pondering after weapons were found in the Pretoria cells of some of his closest associates.

Moyo, who escaped from Boksburg Prison in 2010, is due to appear in the Pretoria Magistrate’s Court on Friday in connection with an escape from the capital’s magistrate’s court in August where he appeared on armed robbery charges.

At the time of the courthouse escape, Moyo was appearing with co-accused, Kumbulani Sibanda, Leon Ncube and Thabani Sibanda on 13 charges, including robbery with aggravating circumstances and possession of unlicensed firearms.

It is alleged they were involved in more than 35 bank robberies.

He came into court on crutches and was not shackled. He was re-arrested in Hillbrow 18 days later.

While prison officials have denied Moyo was found with weapons, sources in New Lock Prison said Correctional Services reaction unit members found a homemade firearm and ammunition in his cell, along with a cellphone loaded with airtime.

The cells of Moyo, Sibanda and another awaiting-trial prisoner jail officials would only identify as Dube, were raided after a tip-off on Wednesday that the three were planning an escape.

Dube is awaiting trial for his alleged role in an armed robbery at a jewellery store in Montana.

The three are interned in New Lock Prison’s high security B-Section. They are seen as extremely dangerous and a high escape risk and are being held in single cells in a section of the prison known as “The Basement”.

In Wednesday’s raid, reaction unit members recovered surgical blades, hacksaw blades, a firearm made from plastic, a cell door key mould disguised as a cellphone and a half-complete plastic key.

Also found, Correctional Services sources said, were eight rounds of ammunition.

“These are the worst of the worst and now they have been found with this contraband. The only way they can get these items is (by) bribing warders,” said the source.

“It is a major security breach and from information obtained it is clear that they were planning an escape soon,” said the source.

Correctional Services spokes-man Phumlani Ximiya confirmed the finds, but denied any contraband had been found in Moyo’s cell.

“That is simply not correct. Your sources have it wrong,” he said.

Ximiya said the recoveries were made following a tip-off from other inmates to prison officials.

During the search prison officials recovered two surgical blades, two hacksaw blades, a key mould made from a cellphone card, an incomplete cell door key made from plastic and a firearm made from plastic, he said.

Ximiya said authorities afe investigating how the items had ended up inside the cells. “Anyone, including warders, found to have contributed to this, will be dealt with severely internally and criminally.”

Teklas uses PP in WIT production

The Turkish company Teklas Kaucuk, which celebrated its 40th anniversary in 2011, has built up core activity in rubber media ducts, anti-vibration parts and windscreen wiper blades.

The company established a plant in Kardjali, Bulgaria, in 2006 and started to use water assist injection moulding technology at the plant at the end of 2009. That first WIT line consisted of a KraussMaffei KM 150-370 CX injection moulding machine and a PMEcube WIT module from PME Fluidtec.

The WIT line has been used to mould 3D cooling water ducts for an Opel 1.4 litre car, using tools from Hofmann Werkzeugbau. Opel originally foresaw a long and complex metal duct, but it finally decided on a plastic version in BASF's special Ultramid A3HG6 WIT grade of polyamide 66.

BASF said in November 2011 that Teklas has since supplied a large range of engine compartment cooling water, air and oil ducts made of the special Ultramid material to "almost all large European automobile manufacturers."

Teklas now has four KraussMaffei machines using WIT in Bulgaria and one at its headquarters in Bayrampas, near Istanbul. These are supplemented by eight Engel vertical machines, four each in Bulgaria and Turkey, that are used to overmould hoses, as well as three 3D blow moulding machines in Turkey.

Teklas uses the "melt pushback" version of the WIT process, while post-moulding robotic systems apply metal rings and TPE seals to the WIT ducts.

Looking at other technologies, Teklas told European Plastics News that a completely new development in 2011 was its use of a special Polyfort unreinforced polypropylene from Schulman. This material will this year be used for serial production of automotive drainpipes with integrated flexible bellow sections that facilitate assembly and allow for movement during driving.

European Plastics News spoke to Teklas' new business development and R&D director, Murat Bozkurtlu, and Schulman's innovation manager, Thilo Stier, on Schulman's stand at Fakuma 2011. Bozkurtlu said the new PP plastic duct made in the WIT process is a substitute for a rubber duct that Teklas was blow moulding for Opel.

At the time of the Fakuma meeting, Bozkurtlu said prototype tools had already been cut and he showed an example of a moulding produced on these tools (pictured above). The tools were made by the local Turkish mouldmaker Elvanlar Plastik, based in Gebze, within an eight-month development time. Teklas says it carried the full cost of the prototype tools.

While the example showed at Fakuma had one bellow section, Bozkurtlu said a two-bellow version has been designed for serial production by using hot runners. This first plastic version of the pipe belongs to the Opel "Delta" platform that includes the Astra car; there are around 1.5m Delta platform cars in worldwide production.

The two-bellow series production tool was ready at the end of January 2012 and another 12 tools will follow by the end of March for serial production of a number of PP ducts and other items, Bozkurtlu said last month.

"The established blow moulding solution makes no sense compared with the highly integrated PP plastic version" if you consider the blow moulded part's need for clips to be assembled onto the ducts, says Bozkurtlu. The integrated bellows on the WIT ducts replace O-rings applied to the blow moulded ducts, although Bozkurtlu says the injection moulded version also uses O-rings, but these are "just for sealing".

Stier points out that the special Polyfort PP material has sufficient melt strength to withstand not only the application of water in the WIT process to from a tubular structure, but also a second "blowing" application of water to form the integrated bellow sections. Teklas has applied for a patent for this special technique.

Artist of the week 168: Svein Flygari Johansen

Svein Flygari Johansen is a modern-day Romantic. While his hero Caspar David Friedrich captured the mysteries of mountains and forests in paint, Johansen uses the latest technology for his ecologically minded projects. In his UK debut, Am I Making Up What Really Happened?, the fusions of art, nature and science (created with his technical collaborator, Jonny Bradley) include a giant plastic sack of fish-free Thames river water suspended from the ceiling in a low-lit, cave-like gallery. Beneath it, the twitching shadow of a trout swims across the floor as a digital projection. The effect is magical, like seeing a ghost.

Though now based in Oslo, Johansen was born and raised in Alta, the northern-most city in the world, and the raw Nordic fjords and forests are at the heart of his work. As a boy, he campaigned against the Norwegian government's controversial plans to build a power station and dam on the local Alta-Kautokeino river. It proved a formative experience, focusing his attention on conservation and the age-old culture of Norway's indigenous Sami, whose land rights were thrown into question by the government proposals.

The conflict between old and new ways of life is brought into focus in works such as the photo diptych The Fence (2007). In one image where fresh grasslands are lit up by a blue summer sky, a rickety wooden Sami reindeer fence winds. In the other, it's winter, the landscape muddy and sliced in two by an industrial white metal fence, heralding the privatisation of ancient common land on the borders of Norway, Sweden, Finland and Russia.

A similar tension is at play in the shimmering limestone humps that spread across the floor in his current show like a scaled-down Nordic landscape. Yet this panoramic vision of untouched natural beauty palls somewhat when you discover the sparkle is thanks to a crystal coating of ammonium sulphate, a chemical more commonly used in industrial fertiliser and related to the nitrate used in explosives.

There's a sleight of hand, now you see it now you don't, quality to Johansen's work. He points to what is lost in a changing world, where ancient ways and eco-systems succumb to the rapid march of global capitalism.

French scientists invent tough plastic

French researchers have designed a polymer that can be heated and reshaped, and yet remains as strong as well-known industrial plastics.

The new polymer is unusual as it can be repeatedly processed at high temperatures; 'it can even be ground up and recycled into a new shape while retaining the mechanical properties of the original material,' according to the study, which was released on Thursday in the US journal Science.

Complex shapes can be easily made without resort to a mould, and, since the material will not melt, precision heat tools are not necessary and a hot air blower is sufficient, said the study.

Once further developed, the material could find uses in aircraft and car parts, construction, electronics and sports equipment.

Until now, synthetic polymers have been divided into two classes: thermoplastics that can be melted and remoulded, and thermosets that are processed into liquid, chemically infused and moulded into a permanent shape.

The latter are the strongest and most stable, particularly at high temperatures, and are often used in aircraft. But they cannot be broken down again and reshaped.

The material created by Damien Montarnal and colleagues at the Ecole Superieure de Physique et de Chimie Industrielles in Paris is as strong as a thermoset but can be repeatedly manipulated into different forms.

'It can even be ground up and recycled into a new shape while retaining the mechanical properties of the original material,' said the study.

The material has not yet reached mass production, but researchers said the process for making it could be 'readily scaled up for applications and generalised to other chemistries.'

Beef: a buyer's guide

After an animal dies, enzymes are freed from the control systems that keep them in check during life and they start to indiscriminately attack the cell molecules around them. Fortunately for the eater of its meat this violent rampage boosts flavour and increases tenderness.

Larger low-flavour molecules are broken down into smaller, flavourful fragments, fibres are loosened and connective tissue starts to break down. All this helps to turn the mild flavour and springy texture of fresh meat, which may look beefy, but is often watery and insipid, into tender mouthfuls of intensely flavoured aged beef. The extent to which this process takes place depends on what happens to the meat after the animal is slaughtered.

Our Longhorns are split into two "sides", each of which is then hung in a cold room for 21 days. These sides are then cut into sections (eg a run of ribs or a whole rump) that are left for another 14 days. We've found that the rump improves after a further twenty days, so, whilst most of our steaks come from meat that has been "dry-aged" (as this process is known) for 35 days, our rumps get 55.

Walk into the ageing room at the farm and you will be confronted by a wall of meat and a pleasant musty smell with a touch of blue cheese to it. The process of dry ageing promotes the growth of certain moulds on the external surface of the meat that produce their own enzymes, further helping to tenderise and boost flavour. By the time it's ready to eat, the beef will often have a thick bloom of mould, all of which needs to be lopped off before the sections are cut into steaks and cooked. The meat we use doesn't get vac-packed: in fact, it never comes into contact with plastic at all.

At the other end of the spectrum, industrial beef producers like to do things a little quicker. They might run an electric current through a fresh carcass for up to 30 minutes, as they've found that this can help tenderise the meat, before breaking it down into steaks and other cuts in a process known as "hot boning" because the animal's body is still warm. Most of this meat will end up on supermarket shelves within a few days, but some might sit in their vac-packs for a while, a period known to some as "wet-ageing".

When meat is dry-aged two beneficial factors are at play: those rampaging enzymes and water loss through evaporation (fresh beef is about 70% water). After 35 days our beef will have lost about 20% of its weight and, as this lost weight is flavourless water, the flavour of the remaining meat is intensified. Added to this, any surfaces exposed to the air during dry-ageing need to be trimmed, resulting in even more weight loss. Mass beef producers don't like this as it means they have less meat to sell, so in the 1970s they found a solution: wet-ageing, which results in zero weight-loss (unless you count the bloody, but flavoursome juice you have to pour down the sink when you open the vac-pack).

For the eater, though, this beef misses out on that all-important intensification of flavour, it can also lead to slightly sour and metallic flavours in the meat due to increased acidity, and it prevents some of those enzymes from doing their cell-busting work, resulting in less flavourful meat. Another counter-intuitive result is that dry-aged beef with its lower water content also ends up seeming juicier than wet-aged beef.

The Halloween Collection of Sarah Hill

Model Sarah Hill is a former member of Houston Press's Gothic Council that we have previously described as Mary Poppins as imagined by Quentin Tarantino. She maintains an amazing collection of vintage Halloween memorabilia and spooky knick knacks. Thousands of items are carefully arranged all around her home, with hundreds more awaiting display space in her attack and office.

"I've loved Halloween since I was a kid, but not for the typical reason of getting to dress up," said Hill. "I'm attracted to things aesthetically. I find a lot of comfort in certain colors and visual aesthetics you see in a lot of Halloween stuff. Christmas stuff too, actually. I like to surround myself with these objects and just look at them. I don't know what's it's like to be a drug addict, but this is my addiction. It makes me happy."

With the Halloween season in full bloom, we asked Hill to take us on a little tour of her collection, and found five of her most interesting items to feature.

The first exhibit was a vintage candy container from the 1960s that is a jack o' lantern on top of a clear black cat in which candy corn is stored. The candy in the container is actually the original candy corn that was packaged with the novelty. Jokingly, we asked Hill if she'd ever been tempted to try the ancient confections. She said no, one of the reasons being that when she received the item from eBay the hollow base had been full of dead beetles who had become trapped while trying to get to the candy corn and died.

The candy should be perfectly safe regardless. The sugar acts as a preservative in most treats ensuring that they never really spoil. We actually developed a taste for expired chocolate thanks to a disreputable vending machine supplier. Still, it almost certainly tastes terrible since it was manufactured half a century ago. Well, more terrible than candy corn usually tastes, anyway.

Hill's favorite things in her collection are Union Products blow moulds, the light-up plastic yard decorations that were popular until Walmart put the company out of business in 2006. They were the creation of Donald Featherstone, an Ig Noble Award-winning artist who was also the designer of the pink flamingo yard ornament. There are more than 100 of these rare and hard to find items in her collection, though she says her hoard is only an eighth of the size of a friend with similar tastes.

Hill is sensitive to the way light affects her moods, and particularly enjoys the illumination from the moulds. The prize in her house is an extremely rare mould of Bela Lugosi.

"I'd love to go up one day and put all of the blow moulds on my roof," she said. "It would really perk up the day of the people on the planes that are always overhead."

She next drew our attention to a liquor serving set from 1950s Japan meant to look like a poison decanter. Made of porcelain, there's a tremendous market for these items on eBay. They're a perfect companion to the Michter's Whiskey bottle shaped and painted like a witch riding a broomstick. Michter's Distillery was founded by Mennonite famers in the 18th century and produced a variety of liquors until it closed in 1989. They were famous for the variety of special liquor bottles including the above which, a football, and the death mask of King Tuthankhamun.

Does your building cough and sneeze?

Do you constantly have headaches, eye or skin irritation, sniffles, sneezes, dry cough, fatigue, dizziness or even flu? You could be suffering from the effects of a poorly constructed house.

Some houses are either built using inappropriate materials or are too close to one another, leading to lack of ventilation and poor lighting.

"Walking into a modern building can sometimes be compared to placing your head inside a plastic bag filled with toxic fumes," says John Bower, an author of several books on healthy home construction.

Sick building syndrome is a term used to describe situations in which building occupants experience acute health and discomfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified.

Last month, the Director of City Planning and Nairobi City Council, Tom Odongo, alluded to a study that has shown that more and more people in Nairobi’s Embakasi area are suffering from respiratory diseases.

This syndrome is common in many low-income residential areas in Nairobi because of the limited or no spacing between buildings, which leads to poor ventilation.

Also, Nairobi being a swampy area, especially the plains of Eastlands, there is always the risk of damp raising, where water seeps into the walls, causing dampness in rooms. Using chemicals in a poorly ventilated building can also be hazardous.

Occupation certificate

"From the way a building is designed to the materials used for its finishes — whether it is the wooden floor or paint on its walls — the causes of sick buildings are frequently pinned down to flaws in the ventilation, level of dampness or air conditioning," explains University of Nairobi don and environmental design expert, architect Musau Kimeu.

According to Architectural Association of Kenya chairman Stephen Oundo, this problem has several faces and the blame lies either with the developer, the professions employed by the developer or the approving authorities.

Oundo says most of the city developments do not have an occupation certificate and, therefore, their human habitation status cannot be verified.

Having an occupation certificate shows that the building is suitable for occupancy. City councils or Municipal councils issue this certificate to show that a building has been built in compliance with the Building Code.

Kimeu, who is the chairman of the Environmental Design Consultants Chapter of the Architectural Association of Kenya, adds that dampness in your house causes mould, potentially causing allergic reactions and respiratory problems.

In the office, you find that employees get symptoms such as eye, nose and throat irritation as well as neurotoxic or general health problems.

Kimeu, notes that the main cause of such discomfort is poor indoor air quality, which is as a result of poor ventilation.

Says Kimeu: "The big challenge of course is for everyone to understand why these symptoms occur. There are times you walk into the office and you start having a headache, dry cough or feeling dizzy and too tired to execute your work. It could be because of a sick building."

A World Health Organisation report suggested that up to 30 per cent of new and renovated buildings worldwide may be linked to the symptoms of sick building syndrome.

Kimeu says that apart from inadequate ventilation, sick building syndrome can be attributed to chemical contaminants like volatile organic compounds (VOCs) from office machines, carpets and furniture as well as biological contaminants like bacteria, moulds, dust mites and viruses. These can cause acute effects on the occupants of a building.

These biological contaminants may breed in stagnant water that has accumulated in ducts or ceiling tiles, which may in turn lead to symptoms like cough, chest tightness, fever, chills, muscle aches, and allergic responses such as mucous membrane irritation and upper respiratory congestion.

What then can be done to correct this? Oundo says cross ventilation should be incorporated in building designs to increase air circulation and ensure proper ventilation.

"This can be done by having windows on opposite sides of the room, resulting in free airflow across the space," explains Kimeu.

Oundo also says ventilation standards in the Building Code should be adhered to and this can be achieved through proper and transparent enforcement by the relevant local authorities.

Kimeu, on the other hand, says it is important for architects to ensure there is sufficient natural ventilation in buildings and for users to ensure there is no contamination through dampness or water spillage.

"Nairobi’s tropical upland climate is so good that all buildings, if properly designed, can be naturally ventilated," says Kimeu.

There are also those building materials that are toxic in nature and architects should specify non-toxic building materials that have been tested and approved.

Golden vision for men with mussels

WAY OF LIFE: Waylon Brown (left) and Cost Peters use "walking wheels" to lift buoys and the

"backbone" lines on a Gold Ridge mussel farm to re-seed it with juvenile greenshell mussels

encased in stocking to keep them next to the dropper rope until they form a secure attachment

of their own. By Elaine Fisher

HARVEST COMPLETE: One of Gold Ridge Farm's mussel barges heads back to Sugar Loaf wharf in

the Coromandel Harbour to unload a morning's harvest of greenshell mussels ready for

distribution to North Island supermarkets.ABOVE: David Myers, operations manager of Gold

Ridge, opens mussels taken straight from droppers on one of the Coromandel marine farms.

LEFT: Bags of young greenshell mussels have been graded for consistent size before being used

to re-seed a section of one of Gold Ridge Marine Farm's mussel farms in the Coromandel

Harbour. Gold Ridge Marine Farm

The thriving mussel farming industry off the Coromandel Peninsula may owe its existence to a

Peruvian earthquake in the 1960s.

Industry pioneer Gilbert James doesn't discount the possibility that the tidal wave created

by the quake across the other side of the Pacific may have destroyed the Coromandel wild

mussel population but whatever the cause, he was able to see an opportunity for farming

mussels to meet the needs of an already established market.

"Wild Coromandel mussels harvested by dredges had been in demand and available for 50 years

in Auckland and the Waikato, including sports clubs and fish shops," he said.

While his father Joe James believed over-dredging of the beds by harvest boats probably

caused the demise of the wild mussels, Gilbert said another theory was that the tidal wave

was to blame.

"In New Zealand it passed almost unnoticed as it happened at low tide but Coromandel locals

remember the tide coming in when it shouldn't have and then receding to below normal levels.
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It opened up an area between the mainland and Whanganui Island now called Little Passage and

many people think it moved sediment from the Waihau River and upper Thames Estuary over the

beds smothering the mussels which died and became putrid and the beds never recovered."

However, even though the wild mussels began to disappear in the 1960s it wasn't until 1984,

after years of planning and application rejections that Gilbert finally gained a licence to

establish a mussel farm in the Hauraki Gulf.

Today the company Gilbert named Gold Ridge Marine Farm is a thriving business in the Gulf and

supplies most North Island supermarkets with fresh mussels year round.

It's been a long and sometimes troublesome voyage to reach that point.

Gilbert grew up in Coromandel, the town his great grandfather Samuel James came to from

England in 1875, lured by gold mining. Samuel established a merchant's store, supplying

mining equipment, including dynamite, and general goods. Today his name is preserved in the

main street park where he built rest rooms for mothers and babies and in the James & Turner

store not far up the road.

It was Gilbert's grandfather Arthur James who bought an abandoned gold mine and the land

around it at Preeces Point just south of Coromandel where today Gold Ridge Marine farm has

its land-based operation.

"We didn't live here, but as a child this was my playground. We roamed freely around the

hills and harbour," said Gilbert. There's still gold in the old mine which was abandoned when

the seam was lost. Gilbert has no plans to re-open it - he's more interested in what he calls

the gold in waters of the Gulf - the greenshell mussels.

By the 1960s Gilbert had left Coromandel, working first as a shearer and then as production

manager for Wattie's at a maize starch factory in Auckland. However, much as he enjoyed that

experience, he was already planning to farm mussels.

"I knew there was at least a 2000 bag market between Auckland and the Waikato."

Mussel farming began in Marlborough before it got started in Coromandel and Gilbert and other

North Island marine farmers were able to learn from the South Island experience, adapting

techniques to suit local conditions.

Having a land base was essential and for that Preeces Point proved ideal, providing the

ability to bring a flat bottom mussel barge in close to shore. However, the barges load and

unload their harvest and all their farm gear at the Sugar Loaf wharf not far from Preeces

Point.

Gilbert believes in running an efficient and cost effective operation, employing the best

people he can and carrying out as much of the operation as possible in house.

That includes manufacturing the distinctive large black mussel buoys which support the 'back

bones' and droppers of the marine farms.

"If we needed a large number of buoys in a hurry we often couldn't get them and don't have

the room to stock pile them so we decided to make our own. It's far easier to store 15kg bags

of the raw material than buoys and moulding them also gives staff diversity of work which

they enjoy."

Key mussel buoy maker is Trish Janmaat. She can produce one buoy an hour using the large

mould, filled with granulated plastic, which is baked in a special oven which reaches

temperatures of 270C. The mould constantly revolves inside the oven, causing the melted

plastic to adhere to the sides to produce the buoys.

"When we first started we cut the buoys open to find out how well they had been moulded. I

didn't care how many we destroyed so long as we got the method right," said Gilbert, who

expects the buoys, which retail at about $140 each, to last up to 10 years.

Threading 6km of cotton "stocking" onto a 110mm diameter pvc pipe is another essential task

and David Blythe, Gold Ridge operations manager and Gilbert's partner in a mussel farm in

Wilson's Bay, demonstrated how the stocking is automatically fed onto the pipe in preparation

for use during re-seeding of juvenile mussels out on the water.

Outside in the yard are large mussel sacks full of what looks like frayed rope. Gilbert

explains that the rope's 'frayed' nature gives extra surface area for the mussels to attach

to.

He's impressed at a new rope invented by Nick Franklin of Auckland especially for mussel

farmers.

"It is a braided, not twisted rope so it's not constantly trying to unwind like the ropes

we've used for years have. I think it's pretty remarkable that someone can invent a new rope

and that's just what Nick has done."

To understand how the buoys, stockings, ropes and shellfish all come together, Gilbert and

David took us out to see a re-seeding operation on one of the farms in the sheltered waters

off Rabbit Island.

We watched as Costa Peters and Waylon Brown finished harvesting young mussels from one of the

outer lines of the farm, stripping the shells from the rope in a machine mounted on the barge

deck, and grading them for size.

"It's better to be growing mussels of a similar size together, because they will all mature

around the same time, " said David.

The crew began work at day light but within just a few hours the mussels were back in the

water. Bags were hoisted by an on-board hiab and emptied into a hopper, to be released at a

pre-determined rate into the stocking-covered pvc pipe through the middle of which ran the

continuous growing rope.

The stocking holds the mussels close to the rope until they re-attach, often within hours,

and over the next few weeks the fabric rots in the salt water, allowing the mussels to grow

to harvest size.

Today nearly every supermarket has fresh mussels on sale and in the North Island nearly 50

per cent will be from the Gold Ridge farms, harvested four times a week and delivered fresh

by another partner company, Future Cuisine.

To ensure food safety and the quality of greenshell mussels there are strict conditions

around when they can be harvested.

Because mussels are filter feeders, they can't be harvested for a prescribed period after

heavy rain which may wash containments and bacteria into the sea.