Quick Sanding in Abu Dhabi


09. March 2015

The Probst Easyfill EF-H Stone Tile Jointing Machine in Action

Abu Dhabi is a city of builders. Today, you will hardly find more than a few larger or more impressive construction projects anywhere in the world. The new presidential palace with numerous side buildings was built on 150 hectares [538 acres]. A large plaza in front of the palace measuring about 300,000 m² is covered with natural stone tiles of superb quality. Perfect workmanship and the use of precious materials create palatial splendour. Project engineers require first rate quality from hired builders and service providers. Every detail counts. This includes using the proper tools and machines for the sanding of the precious ground covering. Probst Easyfill EF-H Paver Jointing Device is the natural choice for creating the required perfection.

In Abu Dhabi, a rapid shift to cool nights follows the heat of summer days. Daytime temperatures above 40 degrees Celsius [140 ºF] are quite common in Abu Dhabi. Rapid temperature changes are liable to cause stress fractures in natural stone surfaces. Engineering prevents this problem. The tiles are placed so that the joints have just the right dimensions and the grouting material consists of a specially adapted elastic material, which conforms to the tiles as they expand and contract. The joints must be completely filled with stable granulous grouting material to show the elasticity, which is essential for durability. In this way, local stress is distributed across large areas. This makes the surface cover stable and capable of absorbing stress.

How long would it take workers to sand and finish an area as large as 28 soccer fields? The answer of the construction experts in charge was quick and easy: too long! Therefore, the construction firm decided to buy several Probst surface jointing machines. The workers move the Easyfill EF-H jointing machines by hand. Replacing the traditional broom with the Easyfill EF-H jointer increases the speed by a factor ten. Working with the Easyfill EF-H jointing machine is also far easier than the traditional method. Workers will appreciate this fact on hot days.

The floor tile jointing machine features two crosswise arranged brushes, which are geared into each other, thus creating a forward drive. The brushes are powered by a 5.5-PS gasoline motor. This motor provides 80 % of the required sliding force. As a result the machine moves forward almost on its own. The operator's main task is keeping the jointing machine moving in the desired direction.

The jointing machine determines the speed. Therefore, the joints are optimally filled in the first pass. This eliminates the need to ensure proper sanding in a second pass. The front of the machine hood slopes back so that the operator can reach even small and hard to reach areas.

Still, the workers must move the machines about 250 km on foot to sand the huge plaza. The machines are regularly passed from one worker to the next. Fortunately, it takes only one click to adjust the machine handle to the body size of every operator. Guiding the machines is virtually child's play. Most importantly, it is gentle on the back.

Before the joints can be filled, the sand must be spread on top of the tiled floor. If the spreading is very uneven some brushes may not be able to handle the load. This is no problem with Easyfill brushes. Probst engineers spend a lot of effort on selecting the optimal parameters for bristle rigidity, elasticity, and resistivity. As a result, the bristles never lose contact with the tiled surface. This ensures highly efficient bristle movements.

The individual bristles have a reserve of 50 mm to account for wear and tear. This guarantees a long bristle life and minimum maintenance requirements. The patented quick-adjustment spindle allows the continuous adjustment of the bristle length. This keeps the bristle wear and tear to a minimum.

While sand is certainly more common than stones in Abu Dhabi, every now and then, a small stone or a piece of debris will lodge between the crossed brush arms and stop the brush rotation. Fortunately, an overload protector is a standard feature of the EF-H. This safety feature prevents damage to the bristles and the drive mechanism. A long productive life of the EF-H is the result.

The wheels of the Easyfill machine are made of undyed natural rubber. This is an important advantage. Unlike commonly used wheels, the Easyfill wheels do not leave streaks or chaff marks on the top-quality natural stone tiles.

Soon our work in Abu Dhabi will be done. The Easyfill machines will then be moved to the next project. For the upcoming project the grout will not be filled into the joints in the form of sand but rather as wet material. Another standard feature of the Easyfill machines are the integrated water taps. The machine operator uses the tap to optimise the consistency of the water-sand mixture. Whenever the grouting process stops, the operator can turn off the water right at the machine.