• Board Replacement Techniques

    One of the advantages of wood as a flooring option is that it can be renewed to look new again. There are times, however, when this can be a challenge. One example is when there is a single board, or several, that cannot be touched up or repaired. In these cases, the damaged boards must be replaced. This article will focus on nail down or glue down board replacements. Floating floor board replacements will be covered in a future issue.

    Board replacement is a valuable service you can provide for your customers. It
    is a specialized skill that will increase your marketability.

    The most important consideration for board replacements is locating a replacement piece of flooring. It must be the same species, width, length, thickness, profile, color, finish and cut as the original flooring material. For factory finished or engineered flooring, make sure to identify and locate replacement material prior to cutting into the floor.

    Once the material is secured, you must ensure the replacement product has been properly acclimated to the environment. The acclimation process will vary depending on the product and the job site.

    As part of the acclimation process, take moisture readings of the existing flooring and the new flooring. These two readings should be no more than 2 percent different from each other.

    Before you make any cuts, make sure that you are aware of radiant heat systems that may be installed below the flooring. For easy identification, you can tape off the board that is to be replaced. To protect the unaffected flooring, apply 3-6 runs of tape along the edges of the base plate of the circular saw and set the depth to the thickness of the flooring.

    The first cut you make should be parallel with the length of the board about 1/2” from the edge, end to end.

    Your second cut should be about 1/2” from the edge on the opposite side of the board.
    The third cut you make should be across the center of the board at an angle. To make extraction of the material easier, make a fourth angled cut that is parallel to the third cut. You should have split the ends of the two parallel cuts where the circular blade left uncut material.

    You should be able to remove the center piece of the cut board easily. Use a sharp wood chisel to remove any remaining pieces of board, being careful not to damage any adjoining boards.

    Remove any remaining fasteners and adhesive from the subfloor. When possible, try to leave the original underlayment material intact. If removal is necessary, replace it with a similar material to maintain the vapor retarding membrane. Clean all debris from the replacement area.

    Measure the replacement area and cut the replacement flooring to length, removing the tongue on the butt-end of the board. Cut off the bottom groove side of the replacement board on the butt-end, as well as along the run of the board.

    You may need to chamfer, or back-bevel, the underside of the board where the groove was removed to allow the piece to fit into the opening without damaging adjoining boards or adjust the thickness of the board with factory finished or previously sanded floors. Dry-fit the piece and make adjustments as necessary.

    Apply a quick-setting adhesive, such as epoxy or carpenter’s wood glue, to the tongues of the adjoining boards. For glue down floors, replace the glue on the subfloor as was previously existing, same trowel notch and spread rate. Carefully insert the new board into place, using a wood block and mallet if necessary. Clean the entire area surrounding the repaired board and ensure the repair is complete.

    Board replacement is a valuable service that is especially desirable when working on historical floors. Whether the board replacement is happening on a nailed floor, a glued floor, or a floated floor, the process may be similar and will be a specialized skill that will enhance your business.

    You can learn more about board replacement techniques from the NWFA’s Installation Guidelines, by attending NWFA training events, and by engaging with NWFA University. For more information, contact the NWFA at 800-422-4556 or visit NWFA.org .

  • Shades of Gray: How to Use Vinegar & Steel Wool to Darken a Floor

    A few years ago, we had a situation where a reclaimed floor had to be repaired in a hurry, but it was going to take six weeks for us to get the same reclaimed flooring, which was a red oak and white oak unfinished product. The customer couldn’t wait that long, so we had to be more creative. We were able replicate the same appearance of the reclaimed floor with new wood flooring by using an old-school method: a vinegar and steel wool solution.

    This solution is often referred to in our trade as “iron acetate,” although from a chemistry perspective, a true iron acetate would need to be more refined. Whatever you call it, the solution has a chemical reaction with the tannins in wood. When applied to a wood floor, the reaction changes the wood to a gray color. How dark the wood gets depends on the species: the more tannins, the more dramatic the color change. The color change is different from the color change created by stains and dyes, which use solvents and pigments to color the wood; the color change with the iron acetate is a chemical change in the wood itself.

    Today this solution is a typical process in our wood flooring business. While we do plenty of wood floors for your average wood flooring consumer, we also do a fair amount of business for high-end clients and designers, and we find this process useful when they are trying to match their wood floor to a custom cabinet or to accentuate their granite. They want something different from their neighbors, and we can combine this process with different stains, dyes, paints and finishes to offer almost endless possibilities in terms of custom color effects. Because the cost is so low—just vinegar and steel wool—it saves a substantial amount of money both for us and our customers, too, compared with other methods to achieve the same effects.

    How-To Basics

    Sometimes people are skeptical when they hear about this method because it sounds too simple. The process is straightforward: You soak steel wool (I usually use 4/0 pads, but you can use different grades and/or bolts) inside a bucket of vinegar. I use plain vinegar, although I’ve read online where people have used red wine or other vinegars, which I assume would create a different color.

    The soaking time affects how dark the vinegar will turn the floor. I’ve done testing where I let the mixture soak for 12, 24, 36 and 48 hours. After 36 hours I don’t notice much of a difference in how dark the floor gets, but I usually let my mixture soak for 48 hours as a standard practice. The solution should stay a clear color; in my experience if it soaks so long that the solution starts to turn a rusty color, it seems to lose its strength.

    Before applying the mixture, I strain it through coffee filters twice. This is a good idea no matter what finish you plan to use, but particularly important if you plan on using waterborne finish, which could react with any steel wool particles on the floor to create small black spots.

    Applying the vinegar mixture to the floor is similar to the process for water-popping a floor: You want to apply it evenly and make sure it is completely dry before going to your next step, whether that’s a stain, dye, paint or finish. Just as when water-popping, take a moisture meter reading of the wood floor before you apply the solution, then wait for it to go back to that same moisture content before the next step.
    For small jobs, I apply it with a rag just like I would when staining the floor, although you can also use a T-bar or lambswool applicator. On bigger jobs, I’ll use a bug sprayer. It’s easier and also avoids the potential issue of too much wood dust from the floor collecting on the rag and affecting the solution every time you re-dip the rag in the bucket. The iron acetate solution isn’t nearly as difficult to apply as an aniline dye, for example, but you do want to apply it as evenly as possible.

    Different Effects

    Just as with stain, how open or closed the grain is will affect how dark the solution makes the floor. Unlike stain, this solution will make the floor darker each time you apply it and won’t cause problems with multiple coats.

    Since this solution creates the color reaction with the tannins in the wood, the amount of tannins in each species and each board makes a dramatic difference on how much color change is created by this solution. As we all know, white oak has a lot of tannins, so it experiences a lot of change: Iron acetate typically makes a white oak floor look gray with brown undertones. Where the white oak has a tighter grain, the color will be lighter.

    Tight-grained species with low tannin levels such as maple and hickory won’t show much change with just a straight vinegar/steel wool solution, but there is another old-fashioned, low-cost option to help with those species. It may sound strange, but to make the effect darker, we coat the wood floor with black tea first. You can simply steep some black tea with water, then coat the floor with it just like you do the vinegar/steel wool solution. Again, you need to wait for the floor to dry before your next step.

    You can get other color effects by adding other colors right into the vinegar/steel wool solution. We’ve used food coloring as well as aniline dye mixed in with the solution to create different colors. Of course, if you do that, you need to be extremely careful with even application to avoid lap marks and other issues that commonly happen when using dyes.

    Reducing Your Risk

    As you’ve already realized, this process, while being tested throughout the years, falls into the category of what I refer to as “tailgate chemistry.” Any time you venture into tailgate chemistry territory, you need to do plenty of testing on the floor with the exact process you intend to use on the job site, because your finish manufacturer isn’t going to stand behind products not used as directed. Test the product with your finish: Does it bubble? Flake? Turn a weird color? You don’t know until you try it. Do adhesion tests and see if you can make the finish fail.

    Experimenting with this process is kind of like being a mad scientist. You can try different species, stains, sanding effects, etc., and mix up the order of the steps you use for different looks. Note that the reaction with the vinegar/steel wool solution doesn’t necessarily happen right away. One day I was experimenting in the shop with my young son, and he said I should apply the solution after I put a white stain on the boards. When I tried it, I thought it didn’t do anything, but when I came back 45 minutes later, it had turned more of a blue color. I set the sample in my showroom, and we sold a job with that color four days later.

    As you go forward with your experiments, be diligent and record everything precisely. I keep a detailed recipe for every single sample so I can reproduce it accurately. I used to keep the recipes on the back of the samples, but I learned that when I was letting customers take samples home, I was also giving our competitors our exact formulas for these custom effects. Now I create a proprietary name and keep the recipes on file.

    One straightforward use for the iron acetate solution is creating a black floor. By far the easiest ebony floor we have ever done was created by using the iron acetate solution on the floor, then applying a black stain. When creating a black floor, you usually water-pop the floor anyway, so using the solution doesn’t add an extra step but has the added bonus of making the floor even darker (I find it makes the floor just as dark as using a dye).

    Another helpful way to use this solution is to help make the floor darker when buffing on stain. Many contractors like to buff on stain but sometimes avoid it because the floor ends up being lighter than it would if you ragged the stain on. If you use this solution first, you can buff the stain on and get the floor just as dark as if you ragged it on.

    As you can tell, the possibilities for using this old-school technique for darkening floors are nearly limitless. In a wood flooring market like the one today, where customers are asking for more unusual and varied custom effects than they ever have before, this is a good technique to have on hand—for little cost—in your wood flooring arsenal.