Our oil-modified polyurethane finish of choice is made by Dura Seal.
Dura Seal is the professional line manufactured by Minwax, but we've tried Minwax floor polyurethane from the big box stores, and it is not the same product.
We’ve been using Dura Seal on our contracting side for about 17 years because
- its quality and color are extremely consistent from year to year and batch to batch.
- it is extremely hard-wearing for the price.
- its perfect viscosity makes it very easy to spread and it levels extremely well.
Dura Seal's Quick-Dry sealer is intended as a primer coat. While there is nothing magic about using this seal coat (their straight, full-strength polyurethane will seal the wood just as well) it can save you an enormous amount of time.
Their sealer is a carefully diluted version of their polyurethane that will dry to the touch before it cures. This allows you to get a coat of polyurethane down over the sealer after only four hours of dry time and without abrasion of any kind.
Most oil-based polyurethanes require 12 hours between coats and you must abrade between all coats. On large jobs, this is hugely time-consuming and the Quick-Dry sealer will save you time and money.
On small jobs (100sqft or so) is is more cost effective to skip the sealer and use three coats of regular DuraSeal polyurethane, but you will only to do one coat a day and you will have to abrade between each (click here for full coating instructions for DuraSeal).
Quick Dry Sealer covers 350-400sqft per gallon and costs $45. Also available in quarts for $18. VOCs are 4.27lbs per gallon.
Dura Seal polyurethane come in three gloss levels: satin, semi-gloss and gloss. When in doubt, we recommend the satin because glossy floors will dull down in high-traffic zones and the contrast against the unworn high gloss areas will be unsightly.
DuraSeal polyurethane covers 500sqft per gallon and costs $50. We also carry the satin finish in quarts for $20. VOCs are 4.09lbs per gallon.
Most of our customers assume that oil-based finishes are the best and toughest coating for hardwood floors, but that is not necessarily the case. Good quality oil-based finishes are still great for floors, but the the 2-part catalyzed commercial waterborne finishes have surpassed them, at least as far as abrasion resistance is concerned. But that hasn't made oil-based finishes obselete; they still have plenty of positive qualities that waterborne finishes don't:
A little bit of color, the easy way
Oil-modified polyurethanes are not tinted with pigment, but they do have a pleasant, amber color that gives wood depth and richness. Modern waterborne finishes do not have any color whatsover and so far all attempts to add pigment to waterbased finishes have fallen far short of the color that oil-based finishes give to wood.
Oil-based finishes take longer to dry because it takes longer for their solvent to evaporate. You may find that annoying if you're trying to get your job done quickly, but the fact that it takes longer for these finishes to skin over means that they continue to flow and find their own level for a long time.
This means that bubbles, skips, and small puddles are more likely to melt away on their own. Waterborne finishes are more weather senstive and can flash dry when the air is very warm and dry.
The main problem with oil-modified finishes is their odor. Enormous quantities of paint thinner have to evaporate out of the finish in order for it to cure. Paint thinner is a neurotoxin and is very hard on respiratory systems. You must coat wearing a respirator with filter cartridges designed to remove organic vapors (dust masks are not adequate) and you must have windows cracked in the affected rooms for the entire drying cycle to make sure the evaporating solvent has a place to escape.
Do not sleep in a house on the same day when an oil-based polyurethane has been recoated and don't let your pets stay there either.