Keeping mowers in good order, well serviced and with a sharp cutting unit set with ‘no-contact’ produces healthier turf. This belief of leading sharpening specialist Bernhard and Company is now fully verified through in-depth trials carried out by the STRI.
Research officer with the STRI, Mark Ferguson, says, “A well-serviced mower will have a longer, healthier life and a mower with a sharp cutting unit will produce superior turf.”
Stephen Bernhard, managing director of Bernhard and Company says, “Mowing is the single most significant component to producing top turf results. But as an industry the process of sharpening has too often failed to carry the weight it should with major decision makers.
“Larger and smaller clubs can often fail to realize that significant savings can be made in maintenance budgets by organizing an in-house grinding facility.”
In the wake of the storm of controversy that has surrounded the conflicting methods of sharpening mowers, STRI decided to conduct their own independent trials to investigate the best way of maintaining mower sharpness.
A year-long study was set up at the STRI and conducted on an area of fine turf dominated by bent grasses and annual meadow grass, typical of a UK golf green.
Twenty plots were set out with ten plots used for each of the mower treatments. Two identical Greens mowers were used for cutting the turf. The first mower was maintained using light contact and regular ‘back lapping’ to maintain an adequate cutting standard. The second adopted the ‘non-contact’ regime advocated by Bernhard, using the company’s Express Dual and Anglemaster grinders to sharpen mower blades, together with a Rapid Facer for routine front edge facing of the bottom blade.
Both treatments were set up and maintained by STRI’s expert groundsmen.
Findings of STRI research
1) Firstly ‘cleanness of cut’ through the non-contact method can have a significant impact on improving turf health.
• Blunt blades rip the grass leaf, producing turf with a reduced resistance to stresses such as drought, wear from play and turf disease. In current climatic conditions it is also vital to note that the grass has less resistance to cold.
• Playing conditions deteriorate as ball roll and bounce are affected.
• And looks also suffer with badly cut turf displaying a white sheen.
• The benefits of cleanly cut turf are that it not only looks good but also is more resistant to the stresses imposed on it.
Mark Ferguson of the STRI says: “Mower with sharp blades will cut the turf cleanly and subsequently playing quality will improve.”
2) This dedicated research also addressed the best way to maintain the sharpness of cylinder and bottom blade, determining that no-contact imposed far less wear on the mower.
• Traditionally some clubs have favoured ‘lapping’ or ‘back lapping’. Back lapping consists of spinning the cylinder in reverse whilst applying an abrasive paste to true up the wearing surfaces.
• With this technique there is always light contact between cylinder and bottom blade during the mowing process. This causes dulling of the two edges and requires frequent ‘back lapping’ to prevent an inferior cut.
Using back lapping greenkeepers could also be cutting the sward much lower than they think, as the mower can cut closer to the ground than the bench-setting. It also highlights the significant increase in wear to mower parts, leading most significantly to the fact that the bottom blade will need replacing far more frequently.
The alternative is the ‘non-lapped’ or ‘non-contact’ method. This process requires clearance between the cylinder and bottom blade, typically the thickness of a sheet of paper. Running the mower with no-contact imposes far less wear on the mower blades – as wearing is caused purely by contact with the grass and top dressing material rather than ‘metal to metal’ contact.
Ideally to maintain the sharpest cut the cutting unit should be ground every 30 days. In addition, the bottom blade can be sharpened regularly with a portable sharpening device known as a Rapid Facer. This piece of sharpening equipment is magnetically attached to the bottom blade and restores the front face of it to the original grind angle.
Summarizing the benefits golf clubs can enjoy through regular sharpening and non-contact cutting Ferguson says: “Improved visual quality and cleanness of cut are key benefits. This can be seen most clearly when leaf blades are looked at closely.”
Time is money
Fully comprehensive, these trials also considered time spent on maintaining the two mowers. Routine back lapping took approximately half an hour compared to bottom blade front facing which took only five minutes.
Monthly spin grinding of the ‘non-contact’ mower was very fast and simple using the Express Dual as it sharpens the cylinder in situ, making the operation extremely quick. Staff also became accomplished operators of Anglemaster and Ferguson says, “Our groundstaff commented on how user-friendly these machines really are.”
Whilst it is recognized that the equipment initially involves an outlay Ferguson adds, “Sharper mower blades produce superior quality turf with a potential saving by reducing remedial action to solve turf problems.”
In the current economic climate as never before high presentation standards on the golf course are essential in attracting and maintaining members and players. And these STRI findings will have a dramatic impact in helping clubs to recognize the true value of a regular sharpening regime.
Bernhard and Company www.bernhard.co.uk