With wood floors, you get the opportunity to change the look and feel of things by having the floor sanded and refinished. That way, whether you’re dealing with an old wood floor whose surface has got worn out over time, or you simply want to set a new tone for the décor by applying a different wood stain and varnish, it can be done. However, the success of this is tied to the results obtained at each stage of the process, right from the sanding itself.
This is arguably the most laborious part of the restoration project. The old finish coats need to be removed, and the surface made uniform, ready to receive the new coats of treatment. Damaged sections should be repaired, gaps filled, and the wood grain left open that way the finish coats that will be applied will bond strongly with the structure.
During the sanding, there is lots of room for error, and this is especially for the DIY and rookie projects. For instance, one may make the mistake of turning on the sander when the drum is on the ground. This slight oversight will cause it to spin on that spot, creating a divot. When working on wavy floors, it takes great skill not to leave chatter marks. Even how the sanding machine is moved over the floor matters. Going too slow will cause the floor not to be excessively sanded, reducing the wear layer more than required. Remember that the goal is to sand just enough that the old finish coats are removed and the bare wood surface is ready to receive the wood stain and finish coats – not grind through loads of wood tissue. Each wood floor has a limited number of times that it can be sanded, thus the need to ensure that it is not overdone.
On the other hand, there are those who sand too fast, in an attempt to avoid oversanding the floor. However, this usually leaves patches of the old finish coats on the floor. For these sections the new treatments will be prevented from bonding with the underlying wood – meaning that the resultant finish will be weak, and require to be replaced much earlier than had been anticipated.
After the floor sanding has been completed, the next stage is the finishing, where different products can be applied based on your particular needs. From the wood stains for those who want to give the floor a particular colour, sealants to increase the resistance of the boards to spills, to the lacquers and varnishes that come in to protect the underlying floor from effects of wear and tear. When applying the various coats, there are also some mistakes that rookie contractors tend to make, especially when rushing the process.
Take during water-topping for instance. Many tend to water-top the surface before the staining, and then wait for the floor to dry before they proceed to apply the wood stain. There are also those who choose to wait overnight. The goal is usually to wait for the floor to feel dry to the touch. However, this cannot be accurately determined unless a moisture meter is used before and after the process. This is why you will find the professionals using the meter to check the reading before and after water-topping, to ensure that the same readings are obtained – which will indicate that the floor is ready for the staining.
The drying times for the stains are usually rushed as well – even though nowadays many of the stains on the market have cut down their drying time to as little as 2 hours. This duration that’s recommended by the product manufacturer is to ensure that the formulation has been given sufficient time to bond with the wood. What’s more, the drying times that are used when setting these limits can vary with the environment of the actual site – such as when there are conditions in the environment that prolong the drying time – like during those cold and humid days. Particular note should be taken for those sections where the wood stain does not get sufficient exposure to air circulation – such as for the cracks and gaps, since in these sections the solvent that is in the wood stain will not evaporate easily, causing the drying to slow down.
What happens when you apply additional coats over a wood stain that has not properly dried? Well, this will vary based on the type of finish that is used. For instance, if you’re working with oil-based polyurethane finishes, then there can be issues like solvent lock, where a white haze develops in the finish coat. There may also be white lines on the edges, which are an indication of lack of adhesion. On the other hand, for the waterborne finishes, there will be while lines that bridge across the gaps, a hazy finish, and cases of peeling.
Some situations will call for two or more finish coats to be applied. Even for these, you will need to allow sufficient drying time between the consecutive coats. When one rushes, the final result is ruined. For instance, with the oil-based finishes, there will likely be alligatoring effect, or a texture like an orange peeling, which is due to the uncured solvent trying to find a way to escape. There will also be peeling and white lines for the rushed water-based finishes.
The risks of rushing the process are simply not worth it. From DIYers to rookie contractors looking to get through the job fast, it ends up costing more in the long run due to the amount of effort and resources that will need to go into rectifying the situation. The instructions that come on the product label should be followed, keeping in mind that the environmental conditions of the job site will also affect the process, especially the temperature and the humidity. Note that even if the applied coats appear dry enough for more topcoats to be added, you should stick to the recommended drying time at the very least.