I've always said one of the most durable (not practical) floor finishes is the polyurethane varnish. Doing it right means applying at least 3 coats and scuffing between coats. You must allow enough drying time between coats , and the finish must cure for 2-4 days before you use it. It's a long and drawn out process, but up till now it's been worth it. My desk sits over a 100 year old white oak strip floor, that I put through this process 20 years ago. Now it has 5 coats of poly on it, and looks beautiful with a warm amber satin glow. But I dread the thought of recoating it. It means moving out for a couple of days. So I put it off , and off, and off........
Up to now I've not been impressed with the new water-based finishes. Most off- the- shelf brands are sold without the catalyst hardener aziradine. Without it, the finish's molecules will not crosslink , so it will not form a tough barrier like an oil based poly. In fact, the lacquer finish I currently use is more durable than most non-catalyized water based finishes. And this particular lacquer has a nice warm amber tone to it , unlike the washed out pale look of the water-based.
Now as pro, I'm allowed to buy and use the catalyst, and I can add an amber dye to the finish, but I like to use finishes right out of the can. Keep it simple , stupid, I always say to myself. Also, I don't like to handle the poisonous aziredine. I've been exposed to enough toxins , I'm looking for a water-based finish that I can use safely and simply every day.
Enter Dura Seal ® . Just recently they have introduced the next generation of water-based finishes, called Dura Seal ® 1000. None of these , thank goodness , requires an additive to make it as durable as an oil based polyurethane. And the material itself gives the wood a nice amber colour. That's because it is essentially a 100% urethane finish, not an acrylic. (the sealer is an acrylic , used only as the first coat)
I've had a couple of long conversations with Bob , the DuraSeal ® rep in Toronto, Canada and one of the first things I asked him was "Is it safe ? ". He quipped back "Yes, as long as you don't drink it". And I would add " as long as you handle it carefully".
Understand that water is not the true solvent in these finishes. It's similar to latex paint in that it contains small amounts of the solvent family called glycol ethers. These disperse the urethane into the water, which simply carries the solids, hence the name water - borne , not really water based. I'll use both terms, as " water based" is easier to say.
Even though these glycol ethers are very toxic by themselves , they are present in the finish in very small amounts. Dura Seal ® 1000 water based finish contains as little as 1% of the most toxic triethyamine, and no more than 3% of the less toxic propylene group. Now compare this with up to 50% mineral spirits contained in most oil based urethanes. Mineral spirits is a skin irriant and is present in the air for days as the finish cures. The only other ingredient you should know about is NMP ( I won't inflict you with the long chemical name). I've been told that this is the stuff that gives the finish the bite it needs to bond with the coat below it . By the way I use NMP at 80% strength in a product called Citrus Strip ® (one of the new safe paint strippers) . I'm very careful handling this product and have suffered no ill affects in 5 years use. I'll show you in a future piece how to chemically strip your floors safely. The NMP present in Dura Seal 1000 ® finish is only at 5%. So like Bob said " Don't drink it." . And I would add " Wear rubber gloves.".
The good news about these water based finish solvents is that the fumes come off the drying finish in such small amounts that open windows and a fan will quickly eliminate them. In 2-3 hours the finish will be dry and you can walk across the floor and cross-ventilate the whole room. If all this talk about toxic chemicals scares you don't be too alarmed. Every time you use a latex or acrylic paint you'll be exposed to those same glycol ethers, you may have experienced dizziness when painting in a closed room. Just open the windows !!!!!!
Although this material was really meant for professional use, only 5% of the pros actually use any water based finishes, and most of them use the non-catalyzed acrylic finishes (very pale). It's up to consumers to demand the use of specific finishes that look good , and wear well. You can have your cake and eat it too. Durability and low toxicity, I believe Dura Seal 1000 ® water based finish will deliver both. I' ll soon find a client wanting these features and I'll report back to you on tips and techniques. I can't wait to try it out.