One of the lesser discussed aspects of hardwood finishing and refinishing projects is the role of time. The reality is that finishing time is not only determined by the product but also by other specific external factors and application choices too. So if your floors need to be used fairly quickly, it may impact your finishing project choices.
Here are some factors to consider when deciding on your hardwood finishing project:
Swedish, Water-Based and Oil-Based Finishes
Conversion varnish finishes also known as Swedish finishes are our most popular finishing option. They look great and really bring out the color of the floor while providing superb durability. Glitsa finishes are our favorite Swedish Conversion Varnish Finishes and they suggest a full cure can take up to 90 days depending on the products used but that 80 to 90% of the cure happens within 3 days.
In most cases water-based finishes dry and cure faster than other finishes, sometimes you can even walk on water-based finishes 8 hours after the final coat. A full cure will take between 7 and 10 days (70 to 80% cured within 3 days).
We don't do very much oil-based finishing at Ralph's but oil-based polyurethane finishes take about 30 days for a full cure based on average temperature and humidity conditions.
Be Gentle on Your Floors
The more gentle you are with your floor while it’s curing, the more satisfaction you will get for years to come. Being gentle with your floors doesn’t mean you can’t live on them. Allow 24 – 96 hours to return to your home when conversion varnish finishes are applied. 2 – 3 days before placing, not dragging, furniture into your home. It is a good idea to install floor protectors to the bottom of furniture legs to help prevent scratching and marring.
Impact of Weather
Weather, or perhaps more accurately humidity, is an important factor to consider. Floor finishes contain many independent ingredients such as water, polymer, resin, wax, plasticizers, coalescing agents, and defoamers that, when combined, form a stable liquid emulsion.
Once applied to a floor, most of the ingredients evaporate. What doesn’t evaporate (and is left on the floor) is the non-volatile matter (NVM) or “solids” portion of the finish (polymer, resin, wax, and plasticizers). For best results, this evaporation process must be complete before another coat is applied as a lot of water must evaporate for a coat of finish to dry.
Humidity means that the air is saturated with water and this, in turn, means that the water in the floor finish evaporates more slowly. In very high humidity situations this can lengthen the time a finishing project may take. In the midwest, this is less of a problem and we can refinish floors all year round.
Number of Coats
When choosing the number of coats for your floor finishes, you must take into factor the kind of finish you chose. Water-based polyurethane will typically need more coats than oil-based polyurethane. In the case of water-based polyurethane for a water-based finish, you’ll put down two seal coats and two top coats; however water-based finishes will cure faster than oil-based products, with only about two hours needing to pass between each coat of finish depending on conditions. Typically, a day needs to pass between each coat of oil-based polyurethane, but again, this will depend on the conditions of the job site.
If you need access to the space quickly, you may opt for the water-based finish which dries the fastest. Keep in mind that these are general pointers. Always check the finish label for specific instructions. You’ll find application methods, dry times, and spread rates provided by the manufacturer.
It's always best to work with a professional hardwood finishing service provider like Ralph's Hardwood because they will give you realistic expectations and help you choose the right finishing product that meets your needs.