6 August 1999

Bio oil a cleaner solution

On the face of it, use of

vegetable-based lubrication

oils – and their ability to

biodegrade within 14 days

– looks to be an

environmentally attractive

option. Andy Moore spoke

to a Scottish farmer who is

trialling such products

RELYING on vegetable-based oils to provide lubrication and cooling for hard-working tractor engines and transmissions is not a system with which many traditionalists will perhaps find favour.

For David Hay however, bio lube oil could be the answer to reducing the risk of water pollution around his farm situated in the Scottish highlands.

Based at Rhynd near Perth, his arable farm has more than its share of waterways feeding into the Tay and Earn rivers. As such, his farm is considered to be in an environmentally-sensitive area.

Important as this point clearly is, Mr Hay also considers the possible effect of mineral oil pollution on his crops – particularly on his 120ha (300 acres) of potatoes. Other cropping includes 55ha of barley, and 50ha of oilseed rape (135 acres and 125 acres).

"With more food retailers requesting produce grown under the combinable crops assurance scheme, bio oils could help guarantee cleaner growing conditions," he claims.

For German bio-lube manufacturer Fuchs, Mr Hays business was judged to be an ideal trial site for its range of oils – oils which included grades designed for use in engines, transmissions and hydraulic systems.

Trials commenced at Easter when Mr Hays fleet of four tractors, two forklifts and a combine harvester were drained of their conventional mineral oils and refilled with bio-lube oils.

After a short period of operation, the oils were drained once more to flush out traces of mineral oils and refilled.

Engines were treated to Plantomot 5w/40 grade, transmission and brake reservoirs to Plantohytrac and hydraulic systems to the companys Plantosyn 46 HVI.

Every month since then, Fuchs technicians have visited Mr Hay each month to change the oils, with samples of the used oil being returned to the companys laboratory at Stoke-upon-Trent.

"All the used oils from the machines have been tested meticulously for signs of dirt ingress and metal contamination," explains Fuchs Bob James. "Monitoring the degree of metal contamination will indicate the oils ability to prevent wear."

At the Fuchs laboratory, the results are then compared with manufacturers specifications for maximum contamination levels.

A typical bench mark specification, for example, may be the level of silicon contamination. A high rate may indicate the degradation of seals and/or gaskets.

The extent of such tests can be judged by the fact that the team detected levels of sodium in one of Mr Hays tractor engine oil suggesting a coolant leak.

"During the four months we have been compiling a data bank of the results of all the machines oil samples," explains Mr James. "And tests will continue in this manner for some time."

So far, it is too early draw any firm conclusions concerning performance of the bio lube oil but Mr Hay believes there have been no ill-affects on machinery performance.

"Over the months all the oils levels have remained at the correct stick mark," he says. "No excessive engine oil has been burnt, while hydraulic response remains unchanged."

Lubrication aside, according to Mr James, bio oils degrade by up to 90% in 14 days – about twice the rate of conventional mineral oil.

Although this may be true, tests hang in the balance in respect of the bio oils initial effect on aquatic life and vegetation before the 14-day break-down period is complete.

Bio oils currently cost about two and half times more than conventional mineral oils. Mr Hay believes this could make long term use of these oils prohibitive.

According to John Southey, chief engineer for Mobil, the key point about bio lubes is not their speed of biodegradation, but their potential to poison, specifically aquatic life, during their degradation period.

Laboratory tests performed by the company, he says, would suggest that, while bio-lubes may be suitable for hydraulic systems and less arduous operating conditions, they may not perform so well a mineral-based oils when pushed to the limit.

Bolt-on pump for ATVs gives more uses

A BOLT-ON hydraulic pump unit is now available for ATVs allowing the machines to be used to power a whole range of oil powered implements.

These include generators, compressors, winches and a host of powered hand tools. Hydraulic power can also be used to drive a pto shaft.

Made by AR-Mech based at Tirril, Penrith, Cumbria, the pump is attached directly to the engines tailshaft on the left-hand side of the vehicle, which ensures that oil is being constantly pumped.

A range of fitting plates is supplied to accommodate different makes and types of ATVs.

An oil reservoir and filter is mounted on the left wing of the ATV and a bank of spool valves bolted on to the rear. When the system is not being worked, oil is merely circulated and does not draw on the power of the engine. An oil cooler, complete with fan is built in to the return flow line.

A spool control valve has a pressure release valve to protect from over loads and is set to open at pressures of more than 210 bar. Output from the pump is rated at 50 litres/min, depending on ATV model.

Options include use of double acting spool valves, flow regulators and an engine speed setting kit.