Applying White Wood Floor Finishes in the Current Climate
I don't think anyone can dispute that the climate is changing. You may argue about why, but the facts are it IS changing. We all know about its impact on our lives with increased flooding and heatwaves, but what about the impact on our chosen floor finish, not important? Like everything in life, if you are the one affected, it is essential.
So, let's quickly recap on past blogs; the world has gone over to low solvent finishes because of the impact that solvents have had on the ozone layer and, thereby, our climate. As with many things, there is an ironic twist in that the replacement products we now quite often use (water-based lacquers) are much more climate-sensitive than those old solvent-based products and the very conditions that those old products helped create can cause havoc with modern finishes.
Why is it that water-based finishes are trickier to apply than solvent-based ones? Solvent-based finishes are straightforward, and they contain about 4 or 5 ingredients and the solvent which "flashes off" reliably irrespective of climatic conditions. In contrast, water-based finishes can contain 14 or 15 different elements, all of which need to be in the right place at the right time in the drying process and this is all done purely through evaporation. It is this evaporation process that becomes tricky when the climate is unpredictable, and it is this that can cause problems with some specific products.
So which water-based products can suffer the most when the temperature and humidity go up or down? Well, they all suffer to some extent, but if you stay largely within the manufacturer's guidelines of 18 to 22 degrees centigrade air temperature, 50 to 65% relative humidity, 8 to 12% wood moisture content and a floor temperature that is broadly inline with the air temperature, you will be okay.
However, the current fashion for lighter finishes has been causing some contractors to have problems because those guidelines need to be rigidly adhered to, and not everyone is using the correct measuring equipment.
Why the difference? To make the wooden floors look lighter, the manufacturers add small amounts of white pigment to their products that may be branded "white", "pure", "natural", or something similar. They do this as any liquid applied to wood will darken it to some extent, which is not what current fashion dictates. For these pigments to be even across the whole floor, the finish has to be applied and allowed to dry in a very controlled fashion which does not happen if the wood is too dry, the temperature too high or the humidity too low. Because clear finishes are errr…. clear, a few extra microns here or there makes no difference, but add any colour, and we get the proverbial piebald pony.
So how can we get over this? If you are applying any pigmented product, it is essential to measure air temperature, floor temperature, humidity and wood moisture content. If the room or floor is too warm, cool them down by covering windows and using fans or air conditioners. If the wood is too dry, you will need to humidify the room and let the wood naturally absorb the moisture and the same if the air is too dry (they go hand in hand naturally). If it isn't possible to control these things, put the job off until the conditions become more suitable (early mornings or late in the evening can be cooler) or consider using pigmented oil-based products which are still solvent-free but not susceptible to the problems beset by water-based products.
Whatever product you use, bring it into the property as soon as you arrive to do the job A product that has sat in a boiling hot van all day will not be ready to apply and if it is pigmented BE SURE TO STIR AND SHAKE IT TO ENSURE EVEN DISTRIBUTION OF THE PIGMENT before use. Finally, if you are finishing a resinous floor such as pitch pine, or an oily floor such as Merbau, let the wood settle after the sanding as the heat generated in the sanding process brings resins and oils to the surface, causing more issues.
If like me you are a Pallmann fan the these are the revant products in their range.
Pallmann Pall Pure – Extremely tough two component water based pigmented lacquer. It can be applied directly to the floor in commercial applications or used over Pallmann 325 Primer or Pallmann Pall X 330 Pure or white to create different effects.
Pallmann Pall X333 – a solvent-free two-component oil-based primer that can have Pall 333 colour concentrate added to create various colours or be used in a white format as a base for water-based lacquers.
Pallmann Pall X330 Colour Concentrate - 23 different concentrated colours for addition to Pall X333 Natural or Magic Oil Ergo
Pallmann Magic Oil Ergo: A two component solvent-free oil that can be tinted with Pallmann Pall X333 colour concentrate in any colour (including white).
Pale floors can be beautiful. They bounce light around, creating the illusion of space and tranquillity, don't let them create stress. Make sure the conditions are right.