Hardwood floor sanding in Durban and Cape Town is normally done by making use of a specialised company such as The Wood Joint. Some wooden floor sanding companies hire them in when needed but if you are sanding floors regularly then you may want to consider buying one. There are, broadly speaking, two different types of floor sanders or floor grinders. They are relatively expensive to buy and therefore expensive to hire.
The drum sander is an older technology machine that uses a drum with sand paper of varying grits attached to it. The drum spins in a horizontal direction and removes sealer or coating from the wooden floors. One would typically start with a rough grit like a 40 grit paper or rougher and then proceed through the grits to get a finer, smoother finish on the floors before sealing them. These machines come in different widths and different size motors. All of these machines do a similar job. The wider ones at 300mm wide obviously remove sealer a lot quicker as they are covering more surface area. There are two type of paper one can use. A paper-backed sandpaper which is cheaper but will tear or rip more easily if the drum catches a nail or rough edge on the floor. There is also a cloth backed paper which is about 3 times the price. Being cloth backed it is a lot more durable and won’t tear or rip as easily as paper-backed sand paper. Also because it doesn’t get as hot, it last a bit longer than paper-backed before it becomes dull. This is well worth the investment especially if you have a floor that has rough edges or nails protruding or if the drum sander is an older machine. Older machines tend to rip paper more easily because of worn parts. These machines, if calibrated properly work fairly well as they remove 300mm of sealer at a time. They can be difficult to “drive” as they are continually trying to run away from you in a forward direction and the machine needs to be pulled back against the direction of turn. They can also be very messy because the drum is rotating in a horizontal direction and throwing saw dust up into the air. A word of caution when using these machines. When they are switched on make sure the sand paper is not making contact with the floor as the machine will move on its own, probably slap bang into the wall if no-one is hanging on to it. Or worse still slap bang into the pool if you are sanding a deck. The machine can be tilted back so that the paper doesn’t engage the floor,or they are sometimes lever driven. Always work the floor sander in the direction of the boards to avoid scratching the boards against the grain.
Planetary System Floor Grinder
The other type of machine is essentially a floor grinder and is the same machine used to grind concrete floors to a smooth finish. It works with a motor in a vertical position and the shaft spins vertically as opposed to horizontally. Below the motor are three disks of 180mm diameter which can accept various tools, with varying grit, for different applications. Each disk spins in one direction while the whole set of three disks spins in the opposite direct. It is called a planetary system. They move a lot slower than the drum sander but because they are moving in the vertical direction they tend to keep the dust down rather than throwing it into the air. With the correct tool you can achieve the same result more quickly, with less effort and less mess. Even without dust extraction they are a lot less dusty and the dust can be controlled and extracted up as the machine works. Because they spin slower they are a lot easier to use and can be pushed along with one hand. Dust extraction can be fitted to the machine to result in a 99% dust free process. The idea is to start with a course grit tool, or paper, and move through the tools, or papers, until the desired level of smoothness is achieved. There are also other steel tools which act as rasps or files that can be used for stubborn sealer or to level a newly installed floor where small ridges have been left between boards after installation. These machines sand about 10mm to 20mm from the edge of the skirting so the edge sanding is minimised greatly. These machine can be used with or against the grain as they are spinning cross grain anyway.
At The Wood Joint we use both machines depending on what the application is.
A good finish to use is a water based polyurethane as you will be able to apply multiple coats in one day as it dries very quickly. Apply by roller and brush in the corners. Attach a broom stick to your roller so you can stand and do it rather than kneeling on the floor. A light sand with a very fine grit should be performed after the first coat as the first coat will raise the fibres in the wood. Once these have been sanded off very lightly the second and third coats can be applied. Make sure to vacuum properly to remove all dust before the second coat. Dust settles into the polyurethane and dries leaving it rough. Allow it to dry as per the manufacturer’s specification which should be dry enough to walk on after a short while but it will take several days to hard dry. It is best to take your shoes or boots off when sealing and walk in your socks.
This machine can also attend to concrete floor grinding. There is a separate article on this blog regarding concrete floor grinding.
For a free no obligation quote on dustless wooden floor sanding, please contact us on 082 496 5444 or use the contact us form below.