Finishing FAQs
Not finding what you want? Ask us directly through our Contact Us page.
Q: What kinds of finishes can you apply?
A: Water based polyurethanes, oil based poly, epoxy, conversion varnish, shellacs, lacquer, varnish, water based P1K (polyurethane pre-catalyzed), P2K (additional catalyst added at time of use). We can spray most finishes (this makes for a better quality finish). We use more traditional finishes as appropriate. Overwhelmingly, we use water based finishes. They have too many advantages to ignore: client and worker safety, environmental impact, and they perform very well compared to there VOC (volatile organic compounds) counterparts.
Q: What is the difference between dry and cured?
A: Dry (to the touch) means a product can be handled to some degree. The biggest value is that dust can no longer adhere to it. Usually the state a material needs to be in prior to adding a second coat.
Cured means a product is as stable a state as it will ever be in. The chemical process is complete, the outgassing is past. As an example of the value add to changing to water based products: Our previous pre-catalyzed lacquer would take about 3 days for the primary solvent to largely complete outgassing. Our current water based product (P1K) is about 5 minutes. Note that doesn't mean it's cured, just that the outgassing levels have dropped significantly enough to not need respirators.
Q: Why not use a polyurethane?
A: Polyurethanes are a great finish, but have their own unique qualities. Water based poly is reasonably durable, applies relatively easily, but requires a thick layer of finish. In some cases that may not give the desired impact. Water based poly out of the can is what the finishes industry calls ‘water white’ — it leaves a clear coat when it hardens. It can be colored/dyed to resemble the effects of oil based poly; there is at least one brand that makes a line specifically for that reason. Water based poly also raises the grain when it is applied. This requires more sanding during the finishing process.
Oil based poly is more durable, requires chemicals to clean it up and will out gas while drying. It adds an amber affect to the wood it is applied to. The final finish is also usually thinner, which in some cases is important.
Q: What is a ‘flattening agent’?
A: A flattening agent is added to a finish to create the various levels of shine or reflection in a finish: sheen. In a clear finish it is the cloudy material at the bottom of the can.
From Sherwin-Williams: Gloss and sheen reflectance are measured on a scale of 0 (no gloss) to 100 (mirror-like). Reflectance is typically measured by deflecting a single beam of light at a 60 or 85 degree angle off a surface. The light is deflected into a receptor, which measures the intensity in units. The higher the number of units, the shinier the surface.
Applying the lower sheen it in base coats will mute the depth of the finish and make it appear murky/opaque. That may be acceptable or even intentional (it can help even out the range of color in a material). When possible, the lower coats should be gloss coats.
Q: Why do I care about UV protection? When should it be used?
A: UV protection must be used when a product will have more than a casual exposure to direct sunlight. It makes the finish more expensive
Q: What makes a finish 'exterior grade'?
A: UV protection, and flex agent additives to help manage movement due to changes in temperature & humidity. The longest lasting will include pigments -- the more the merrier. Otherwise the product may require more frequent refinishing.
Q: Wait a minute — changes in color will only be slowed down?
A: All woods change color with exposure to light. Woods that are stained will change some, depending on the degree the stain has changed the base color of the wood, as well as how much pigment is in the stain. Woods that are lightly stained, not stained, or exposed to a lot of light will change the most. In addition, many species are particularly light/UV sensitive. One of the most common species is cherry. It will darken over time, usually most obviously in the first 6 months. It can be stained to look darker at install, but it’s hard to say to what degree (or speed of change) their will be over time. Other woods tend to change color, such as many red, purple, and orange colors, etc. Most will darken.
Q: What about stains?
A: Stains come in three main variations: oil, water, and gel. Oil takes longer to dry, but doesn’t raise the grain in the wood. It requires chemicals to clean up, and takes longer to dry. Water based stains dry fairly quickly, but raise the grain when applied; this requires extra effort to sand the finish off to remove the raised grain. Gel stains are used most often for two different reasons: on closed grained wood, or for a dramatic change in color (some grain will still show; not to be confused with a grain filler). As a gel, it can be left on a surface for a longer period with out running off or drying out, and it has a LOT more pigment and dies.
Q. What are closed cell woods? Why do they need to be treated differently?
A: Closed cell woods tend to have a ‘blotchy’ look when stained — if they have not had a conditioner applied. Sometimes that’s okay, sometimes it is not. Closed cell woods include: pine, spruce, maple, cherry. If you look closely at the wood, the cellular openings are much smaller than open celled woods, as well as other structural differences in the wood. Common species of open cell woods include oak, walnut, mahogany. If you look at a finished piece of these woods with the light reflecting off of the wood you can see how smooth the closed cell type are, and how there are little dashes on the surfaces of the open celled wood (or even open pores like skin). A wood conditioner is usually a thinned clear coat product, or a specialized product just for this purpose. Shellac is a common choice. Open celled woods can have the pores filled for a smoother surface; see below.
Q: I understand that you can’t mix oil and water based finishes?
A: Not true. You can’t mix finish layers that are not hard (or, not cured). For example, latex paint has latex (or similar performing products) in it. Latex is what rubber is based on. It never quite hardens, at least in this context. Most oil and water based products we might use will harden. As long as the finish is hard/dry/catalyzed, it can be coated with out worry. There are finishes that require intermediate coats of other products, but that has much more to do with the way thinners and the chemistry of bonding occur. For most concerns with our methods, the oil/water based controversy relates to stains and clear finishes. It's not likely to be an issue for us. But it does require a certain amount of time.
Q: Can you color the wood or fill voids? Fill pores?
A: Yes. There are a number of methods that can be used to color woods. Two different coloring methods can be used, a pigments, or dye. Pigments leave tiny little pieces in the wood, and tend to highlight grain or other details (such as distressing; oak grain color range after staining is a prime example). Dyes are more like food coloring, they change the color in general. They can be used together: that is what stain is. Additional affects can come by using grain fillers (for open pore woods) that are a different color, or two tone paints (cerusing). Epoxy can be colored, including with a glow in the dark agent, to fill voids or strengthen/stabilize a weak area in material. In the case of clear/opaque applications, objects can be included (such as stones, badges, or momentos).
Q. What finishes are safe to use around my children or around my food?
A. All current finishes that are cured/hard are safe for use in food based areas, including children’s products. That may take a lot longer than expected — as much as a month for the final cure. Some finishes are ready to use very quickly; they usually require regular maintenance. Such as walnut oil, mineral oil, or beeswax. The last two are often used for cutting boards; where surfaces are subject to sharp damaging use, just about any finish would fail due to ‘death by a thousand cuts’. Oils that do not go rancid are a better choice. As long as you are willing to maintain them, oils & waxes are good choices for cutting board or similar environments.
Q: So what is your process for client color selection?
A: We work with the client first for material selection. Then we gather a sample they want matched. No matter what, local lighting (room, time of day, area within a room, etc) will play a big part in how a sample will look. We make up several samples of the materials that will be used (solid wood, sheet good, veneered materials, etc), sanded to the level expected. We arrange for a local finish/paint company to make up samples, including a layer of the clear coat finish (as applicable) and then for the client to review them.
The client is encouraged to take the samples that look correct and view them in the room the finished products will be installed with the lighting that will be installed. If the room is to be painted the sample needs to be checked against the new color as well. They should be viewed in daylight (morning and evening) as well as night lighting. The client will work with the paint store to adjust the color as required.
When the color is acceptable, the client will sign off literally ON the match. We will manage the purchase and pickup of the product from there. This saves the client money & time, and gets the result they require.
Q: What if I want more than just a paint or stain?
A: We will discuss with the client the outcome they desire. We accept that there are limits to our knowledge & experience. We have a couple of local finishers that may be better choices to color your project and will gladly put you in contact with them .