Do's and Don'ts for a perfect coating layer

WORK SAFE

  • Make sure that Safety Data Sheets of the relevant substances are available. 

  • Read and understand the Safety Data Sheets before using the substances.

  • Make sure to have eyewash available in the vicinity of the activities.

  • Always use appropriate personal protective equipment when working with the machinery, such as protective gloves, safety shoes (minimum class S3), safety goggles, safety harness, hard hat, lifeline and protective overalls.

GENERAL

  • Always conduct a cleaning cycle before spraying the coatings. The coating will not adhere as well to soiled glass and will therefore wear out prematurely.
     
  • Make sure the glass is fully dry before spraying.

  • Only use liquid coating. Never use powder coating!

PUMPS AND NOZZLES

  • Make sure to use a suitable diaphragm pump with a capacity of at least 40 liters per minute and a pressure range up to 50 bar (725 psi).

  • Only use a mixing tank with a powerful mechanical mixer.

  • Make sure the nozzles in the spray booms:
  • are all the same, TeeJet XR11004 VK
  • are not leaking
  • are not worn out (yearly replacement is recommended)
  • give a good spray pattern

  • Thoroughly clean the mixing tank, pump, hose and spray booms with water directly after spraying activities.

COATING QUANTITY AND MIXING RATIO

The number of pails of coating per hectare/acre depends on various factors. Van der Waay cannot provide advice in this regard. Please check with your coating supplier.
A spray mixture of 1,300 - 1,600 liters/hectare (526 - 650/acre) gives good results. 

Rules of thumb:

  • If the weather is warm and sunny, then increase the amount of spray mixture.
  • If you apply a large number of pails, then increase the amount of spray mixture.

PREPARING THE SPRAY MIXTURE

  • First fill the mixing tank with at least 200 liters of water, and only then add the pails with coating.

  • Make sure that both the mechanical mixer and the pump are running when the coating is added to the mixing tank.

  • Rinse the pails well above the mixing tank. The adhesive present may have settled in the pails. Without the adhesive, the coating will not adhere to the glass!

  • Consider a loss. Therefore calculate 10% more spray mixture than necessary.

WEATHER CONDITIONS

  • Only apply the coating to a clean and dry greenhouse cover to obtain the best wear resistance.

  • Only apply the coating during dry weather with relative humidity < 80% on a dry greenhouse. A wet greenhouse cover dilutes the layer. When the drying time is too long this may cause excessive run-off and therefore an uneven coating.

  • Keep an eye on the weather forecast. Do not apply during precipitation or when precipitation is forecast over the short-term (within 12 hours). Rain damages a coating that has not yet totally dried.

  • Only apply at a temperature between 10 and 25 degrees Celsius. Otherwise the drying time will be too long and the coating will be wet during the night and may become damaged due to condensation.

  • Only apply maximum wind speeds of 2 m/s (4.3 mph). The layer may become too thin and overspray may occur.

THE APPLICATION

The day before:

  • Set the correct pump flow. Use our handy calculation tool for this.

  • Make sure the travel speed of the Top Cleaner is 25 meters per minute.

  • Make sure the nozzles are adjusted about 30 centimeters above the glass, and cover the entire surface from ridge to gutter.

  • Always do a test run with water first. Do this also a day in advance.
On the day of:
  • Prepare the spray mixture. Use our handy calculation tool for this.

  • Before starting the machine, rinse it until the coating comes out of the nozzles.

  • First open the vents so that condensation on the vents can disappear. This reduces the chance of striping in the coating under the vents.

  • Once started with the application, do not stop until all spray mixture has been sprayed and the entire machine has been flushed with water. The adhesive in the coating will dry up quickly and clog the nozzles.

  • Before rinsing the machine, move it to a part of the greenhouse where the coating is already completely dry, or where no coating has been sprayed yet.

  • If there is spray mixture left in the mixing tank, run the mixer until it is sprayed. This will prevent sedimentation.