The biggest problems outdoor wooden structures face are water (moisture). Pressurized water from sprinklers, or rain falling off a roof without a gutter, will pound away any stain on a deck or fence. Moisture will create problems for the absorption and adhesion of stains and will degrade both the stain and the wood sooner than later. Even if a stain is applied when wood moisture is low, a high moisture environment will create problems. Poor air circulation and ventilation is the most common cause of higher moisture content in wood. Improper air flow forces moisture coming up from the ground to travel through the wood to escape (or stay trapped and grow mildews, molds, and fungi). If your wood is already installed your options to deal with this may be limited. If you have not yet installed your wood there may be some options to take into consideration.
New wood has a number of contributing factors that limit the color, absorption, and durability of an applied stain. In addition to higher moisture content (in wood that is not kiln dried), new wood has higher concentrations of natural oil. This natural oil inhibits the absorption of an oil stain because there is nowhere for the oil in stain to go. The pores of new wood are closed and smooth cut wood will have a mill glaze on the surface that must be removed. Lastly, chemicals in pressure treated wood can also inhibit the absorption of stain.
For these reasons new wood needs to weather for a period of time after installation so that the pores of the wood can open up. The timing of when a stain can be applied and properly absorbed is a balance of a number of variables including species of wood, cut of wood (smooth or rough), and exposures (covered verse full exposure sun, rain, and snow). Wood does not need a year, but typically it needs at least a few months.
The mill glaze can be removed and the pores can be opened up (marginally) by lightly sanding with 60 grit sandpaper, applying oxalic acid/brighteners, or cleaning with a liquid bleach solution. Some wood restoration professionals will even apply a light stripper (and then a brightener) to help “beat up” the wood for better absorption. Testing for absorption and conducting the sprinkle test to determine when the wood will accept stain.
Drying only addresses moisture content in wood and helps to prevent warping and cupping otherwise more prevalent in the natural drying process. It does not remove the existing oil concentration inside the wood. When there is existing oil in the wood there is no room for
additional oil to absorb.
When wood is sitting in a lumber yard it is not weathering and moisture can get trapped in the boards that are on the inside of the wood stacks.
Back priming is the process of staining the back side of wood siding prior to installation. Typically this is common with cedar siding to provide an additional moisture barrier to prevent tannin bleed. “Pre-staining” often refers to the process of staining all sides of wood prior to installation.Typically this is done for cedar shingles at a factory, to provide an additional ground moisture barrier when installing decking that is close to the ground or otherwise has poor air circulation, or installing a second story deck where color is desired on the underside. These processes often present the dilemma of staining wood that is not ready to accept stain. Although there may be a requirement for back priming or staining, the expectations for stain longevity on the exposed surface of the wood need to be reduced.
Pre-staining is sometimes performed indoors, especially in winter months. Staining indoors presents additional drying and curing challenges as there is inadequate airflow as compared to staining outdoors. It is just as important to have air flow over stained wood as having temperatures above 50 degrees Fahrenheit. Dry times can be extended from days to weeks in temperatures below 50 degrees or when there is inadequate airflow.
New softwood often requires a maintenance coat 12-18 months after an initial stain application. Only apply one coat of stain to wood that has been installed for less than one year. In the first year after installation DO NOT apply semi-solids to smooth cut or horizontal wood. Semi-solids can be applied to rough cut vertical wood under a year old from installation. Stain applied to newly installed exotic hardwoods may only last one to three months. We do not recommend staining exotic hardwoods for the first six months after installation unless pre-staining is required for the project, or the wood manufacturer recommends it for their product.
Get a glass of water. Stick your fingers into the water. Bring your fingers close to the wood and shake off some droplets. The goal is not to have the droplets drop a far distance and “splat” on the surface of the wood. The wood is ready to accept stain when the droplets start spreading out and soaking into the wood within 2 minutes. Wood will absorb stain just like it absorbs water. If the wood is absorbing water it is too soon to stain. Note - this test does not work well on exotic hardwoods as their tight grain naturally inhibits water absorption.
Regardless of the general timing listed here testing for absorption is always recommended.
Generally need about six months after installation before staining. This does not mean you cannot have success in 2-3 months from installation.
Generally need about six months after installation before staining.
Generally needs 2 to 3 months after installation before staining.
Both redwood and western red cedar are notorious for having higher concentrations of natural oil in them as compared so many other woods. Until some of this oil has disappeared there is nowhere for new oil to go. Typically these woods need 3+ months before an initial staining. Unfortunately many people who install these woods want to enjoy the beauty of the two tone wood are prompted to apply stain as soon as possible to preserve the look (and often do so prematurely). When trying to preserve the new look consider waiting a minimum of four to six weeks, or until the color of the wood starts fading to allow the wood to open up to better absorb stain. Note that nothing can be done to stop the fading and graying out of the natural two tone of the wood. Once it fades it can only be brought back with sanding. Any gray can be treated with a brightener to restore a more natural blonde color to the wood.
Most stains other than Armstrong-Clark oil based stains require that the previous coat of stain be removed using a chemical stripper followed by a brightener, and/or sanding before applying a maintenance coat. Failure to remove the previous stain can result in absorption and adhesion failure.
Stripping is a chemical process to emulsify a stain (turning a stain into goop) which is then rinsed away. The stripping process pulls out oil from the wood leaving the wood dry. Stripping also darkens wood. A brightener needs to be applied after stripping to neutralize the caustic pH of the stripping chemicals on the surface of the wood while also bringing back a more natural blonde color.
Sanding is often part of the process to remove a previous stain for several reasons. The first reason is that many people are afraid of the stripping process and prefer to manually remove a stain via sanding.
A second reason for sanding is that stripping does not always remove all of a previous stain, even after multiple applications of stripper. Therefore stripping is often used to help reduce the amount of sanding that needs to be done by removing a majority of the existing stain that will “gum” up sand paper.
The final reason for sanding as part of the preparation process is that the surface of wood can be damaged during the cleaning process resulting in “fuzz” or “fur”. Chemicals that are too strong or chemicals that dwell on the wood too long will chemically damage the surface of the wood. Scrubbing too hard, using a brush with too stiff of a bristle, or pressure washing with too much pressure will also damage the surface of the wood. All of these will result in the wood looking fuzzy, furry, or like there are little tiny splinters on the wood. This fuzz or fur needs to be removed before the wood can be stained by sanding. Click here to learn more about fuzz or furr.
Wood that has been aged and untreated for a significant amount of time is most likely to have layers of gray, decayed, and loose wood fiber. If these fibers are stained, there is a risk that these fibers will take the stain with them as they are displaced from the wood. The result is the appearance of stain failure when in fact it is the inability of loose fibers to remain intact. To prepare you must first clean the wood. Wood restoration professionals will follow the cleaning process a light sanding to remove the loose would fibers to ensure longevity of the stain. For hardwoods they may use 80 grit, with softwoods they will use 60grit sand paper. If the wood is in poor shape wood restoration professionals may start with 35 grit before finishing with 60 grit.
Tannins are water soluble natural extractives produced in living wood that protects trees from insects and infestation. When the tree is killed the tannin remains in the wood. The heartwood (inner darker wood) has higher concentrations of sap wood (outer lighter wood). Although tannins are found in all woods, some species like redwood, cedar, and ipe can have much higher concentrations than other woods like pine or douglas fir. Additionally, new wood has higher concentrations of tannin than older wood.
Tannin presents itself in a variety of reddish brown, dark brown, and even a black like colored stains. When leaves and sticks land on wood surfaces and are not promptly removed the tannin will bleed out. The second way in which tannin presents itself is in the form of a blotchy appearance. This is known as diffuse tannin bleed and is common in redwood, especially new redwood, and even more so in new heartwood redwood. Unfortunately customers pay a premium for heartwood only to fight a blotchy look when initially stained. The third and final form of tannin is known as rundown or streaked tannin bleed. This is a visible dark streak often seen in cedar shingles.
The primary cause of tannin bleed is moisture. Some scenarios where tannin bleed can be a
problem include water sitting on the surface of the wood, running behind wood (in the case
of siding), water vapor coming through a wall, or ground moisture that is trapped due to
poor ventilation under a deck. Applying a stain can also get the tannins flowing.
The primary cause of tannin bleed is moisture. Some scenarios where tannin bleed can be a problem include water sitting on the surface of the wood, running behind wood (in the case of siding), water vapor coming through a wall, or ground moisture that is trapped due to poor ventilation under a deck. Applying a stain, whether water based or oil based, can also get the tannins flowing. It is very common for new redwood to look very blotchy when stained.
For wood with poor ventilation (siding or decks with air flow problems) back priming or pre-staining is used to help create a moisture barrier. Additionally the use of a cleaner brightener, or an oxygenated bleach cleaner followed by a brightener, before staining can help remove surface tannin. However, there is no guarantee you can prevent tannin stains with any preventative measures taken.
As part of the preparation process wood restoration professionals will always sand smooth cut wood
prior to applying a stain. This ensures any loose wood fibers remaining on the surface of the wood
(especially if there is fuzzing or furring) are removed to ensure maximum longevity of an applied
stain. Any required sanding should be completed before testing for color.
To clarify wood "fuzzies" or "fuzz" are the result of a chemical reaction from the application of a caustic chemical, and wood "furring" or "fur" is the result of a mechanical process of using too much pressure when power washing. Regardless, they look pretty much the same and used interchangeably even by most professionals.
"Wood fuzzing" results from an over application of strippers. These are caustic chemicals that will create fuzz if applied with too strong of a concentration for a given wood, left to dwell on wood for too long, or a combination of the two. To minimize the chances of fuzz it is a common practice to start with lower strength stripper and work your way up to a higher strength stripper as needed. Do not let the chemicals dwell any longer than recommended in their instructions. Pay extra special attention if you have horizontal tongue and groove wood. This can be found in some exterior applications of hardwoods like IPE. Tongue and groove creates the problem of not allowing water to drain. When water cannot drain even a light strength stripper formula can create wood fuzzies because the solution sits longer during the rinsing process.
Wood Furring is caused by using too much pressure when power washing. The softer the wood the more careful you need to be. Cedar is a very soft wood and will fur quicker than many other woods. You will want to use a fan pattern resulting in lower pressure output. Often this is a white tip on a power washer. Think of power washing wood as using a higher pressure garden hose. You do not want to use the pressure to actually clean the wood. You want soaps and strippers (depending on your need) to do majority of the cleaning and the pressure washing is just a little extra help to remove the unwanted contaminants. When you use too much pressure you will see small specs of wood coming off. If you see this, back off the pressure and or distance your nozzle is from the wood.
In addition to chemical and mechanical causes of wood fur and wood fuzz in the prepping process, we have seen new wood that has not been prepared with power washing or chemical strippers with furring or fuzzing. We are not sure of the causes of this phenomenon, but we do recommend that you inspect your wood before preparing and or staining to insure that there isn't a larger problem that may be difficult to address.
We always recommend testing for color before proceeding with a project. Never rely on a photo for an accurate color representation of how a particular color will look on you wood. Test for color after wood preparation is completed as the preparation method used can affect the final color of a stain. Typically you need to wait 48 hours for wood to dry after washing before applying a sample can to test for color. After applying a sample wait at least 24 hours before viewing color. Never assess color in less than 24 hours. It will take 48-72 hours for final color. Account for this in your project schedule. Armstrong-Clark provides free sample cans at stocking retailers. They can also be purchased online from some distributors. The online fee is to cover the cost of freight. Testing should also be completed for absorbency, especially on new wood. Both the water test and sample cans can be used for absorbency testing.
Factors that can affect the color of an applied stain:
As consumers we can never look at a picture of a stain color in a photo nor a sample of stained wood and assume our project will look the same. There are too many variables that can affect the color of a finished project including wood species, age of wood, cut of wood, the number of coats applied, the exposure older wood has had, and how the wood is prepared.
This is a picture that illustrates how different wood preparation processes can affect color on the very same piece of aged and grayed wood. The photo depicts a single piece of ipe with 2 vertical grooves cut into the wood. The top row is untreated and the color was consistent all the way across. The middle row shows the wood after cleaning. The left side was prepared with bleach, water, and liquid dish detergent. The middle was cleaned with just liquid dish detergent and water. The right side was prepared with a cleaner/ brightener. All sections were stained with the exact same Mahogany stain.
All Armstrong-Clark colors are intermixable. On your own you can create a custom color by blending any of our colors. (Neither stores nor Armstrong-Clark custom blend). We recommend blending whole can ratios when mixing for a project (do not mix partial cans like a ½ gallon). When blending colors for testing color use a measuring spoon and mix in a separate container. Start over from scratch for each blend you test. Do not assume sample cans have equal amounts of stain in them. Once a blend is decided upon mix whole gallons cans in a 5 gallon bucket.
The day you stain wood is the best the wood will look. After application stains are designed to slowly deteriorate. Get on a stain application schedule so wood looks its best during the months you will be using it most. For most of the country this means applying stain in the spring. For the hottest parts of the country this may mean applying stain in the fall.
Do not start the cleaning process and apply stain during the pollen season. Pollen can land on cleaned surfaces after cleaning and can remain under an applied stain. Pollen can also mix into the stain. Mildewcides in a stain are designed to prevent mold and mildew from growing in a stain, but not from growing underneath a stain. Excess pollen can provide more “food” for mold growth than a mildewcide can combat. If this happens a stain must be removed to treat the mildew or mold and prevent wood deterioration.
If painting outside surfaces like a house, and staining a deck, consider the cleaning and application sequence you will want to use. Cleaners/ strippers used in preparing a deck can scar painted surfaces, but house cleaning chemicals that contain bleach can remove soft coat stains like Armstrong-Clark.
Initial review (3 to 6 months out)
Preparation (2 to 7+ days)
Application – (1 to 2+ days)