Floor finishes: offgassing and what to use for tight house?
We’re building a very tight house, and are trying to figure out what floor finishes to use.
Our floor contractor (who we very much like and respect) is recommending an analine die (with 0 VOCs), 2 coats of Bona Woodline Satin (510 g/l VOC!), and a top coat of Bona Traffic (180 g/l VOC). A few questions:
*He says that after 2 weeks of curing, that there will absolutely zero VOC offgassing with these products – will that be the case?
*Is there any reason not to use the Woodline 350 product instead of the Woodline?
*He says that the 2 coats of oil based finish (e.g. Woodline) are necessary to prevent the waterborne die from moving around and in order to have even coloration. Is there any other combo of die and finishes that are healthier and would still provide even coloration and durability? Would using their DriFast Stain (550 g/l VOC) instead of the analine die with 2 coats of the the 350 g/l Woodline be better or worse or make no difference with respect to VOCs in the long run??
*Anybody know anything about Bona Traffic HD (which is lower VOC and advertised as more durable than regular Bona Traffic)? He’s worried about its usability compared to regular Traffic…
Thanks for any and all advice!
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Replies
Karen,
Your questions here may be too specific, because I for one have never heard of the Woodline brand. The manufacturer should help you choose among their products. As for zero VOC after two weeks, that sounds credible because VOC is volatile by definition and dissipates quickly.
Instead of installing two coats of satin under a top coat, use gloss varnish for the first two coats and satin only in the top coat. Satin varnish includes a flatting agent that can cloud the finish if used all the way through.
As an update, we're being presented with two choices, but each has problems:
1) Use the analine dye, which produces a great look, but as per above would require 2 coats of an oil based finish with VOCs, and worse, would bleed into and stain all of our baseboards, and require multiple coats of high VOC primer and paint to repaint.
2) Use a conventional stain that is relatively high VOC, but then would not require any oil-based finish (we could use just the waterborne finish) and would only require minor touch-ups for the baseboard. However, the ebony stain is resulting in a much lighter color than the dye, and we don't yet know how to achieve the same darker/richer color as the dye produces...
Anyone have any suggestions on how to improve on either of those alternatives, or any other suggestions?
Thanks very much.
I'm guessing the issue with dye is that it's water soluble, so it will bleed into water based clear coats. Oil based finishes avoid disturbing the dye. However, you should be able to capture the dye with a seal coat of shellac. Better yet, dye the wood and seal with shellac before installation, say in the garage. That should keep the dye out of the baseboards. But maybe your installer prefers to apply the color in place. I would think at least the baseboards could be installed after the floor is dyed or stained, if you want to keep the colors separate.
You're right that the dye is water soluble. And, unfortunately, all of the flooring is already installed, and the baseboard is already painted with water based paint...
Karen, you've painted yourself into a corner! There may not be an easy fix for your dilemma, but on the plus side it may serve as a cautionary tale that those who aim to build a high performance green home need to plan ahead even more carefully than usual, especially if you're jonesing for a very particular style of finish to go with your new green abode. The deep ebony stain is problematic in a field-applied finish at the best of times - if you hadn't already installed your floors I would have suggested Teragren's pre-finished woven bamboo product - available in a dark chocolate through-color, quite spectacular appearance, and with a 25 year residential warranty.
Depending on what species of wood you have down, there is a technique for ebonizing high tannin hardwoods (red oak, red cedar, redwood) that is much easier to apply than dyes or stains and seems to me to be quite non-toxic. It's an iron acetate treatment, sometimes called Liquid Nightmare. ( http://www.woodweb.com/knowledge_base/Ebonizing_Wood.html )
You soak fine 0000 steel wool in gallon bottles of white vinegar (stuff the jugs full) until the steel reacts with the vinegar to create iron acetate. You get a clear liquid that aggressively reacts to tannins to "rust" the wood a deep brown / black.
We used it on the floors in our house using the original 1960's red oak strip flooring, it turned out great, if a bit nerve-wracking to apply.
Sealed with low-VOC Bona Mega water based polyurethane:
You can use a waterborne product from Vermont Natural Coatings. They have tints that you can mix with the waterborne finish to get the desired color. This is the lowest voc way of getting a dark color. Here is a link to their site. http://www.vermontnaturalcoatings.com/our-products/woodtone-concentrated-tints/ I Usually apply an oil based stain over the anilne dye to make it look more uniform. And then do my coats whether its Bona woodline or Traffic. Hope this helps. Elite Floorcraft
Jesse's suggestion is right on the money for ebonizing, and I'd like to add that you could do a wash with diluted India ink instead--either works. Nice and clear. They do both need a little bit of warming up afterward, at least in my limited experience.
Edit: nice-looking floors, Jesse.