Why Wood Turns Gray If You Use a Clear Finish

Effect of 18 Months of Sun Exposure on Bare Northern White Cedar
Effect of 18 Months of Sun Exposure on Bare Northern White Cedar-Image courtesy Perma-Chink Systems

 

 

“The bottom line is that if only clear coats are applied to exterior bare wood they provide only temporary protection against UV damage.” – Perma-Chink Systems

Our customers often ask us for a clear finish that will protect their wood.  The truth is, clear finishes may provide water repellency, resistance against mold and mildew and insecticidal properties, but clear finishes do not  protect your log home from damaging UV rays that cause graying of your home’s exterior walls, decks and rails.  With most clear finishes you will notice graying wood within 6-24  months of initial application.

Why will the exterior of your home turn gray if you only use a clear finish to protect it?   Clear finishes do not contain the appropriate pigment load to absorb UV rays from the sun. Clear finishes often contain little to no chemical UV inhibitors and the inhibitors they do contain are often “sacrificial, in other words the more UV light that they are exposed to, the quicker they get used up” according to Perma-Chink Systems. The result is a clear finish that breaks down rapidly from exposure to the sun, leaving wood unprotected and exposed to damaging  UV rays.  Wood will then start to turn gray, which is the natural reaction of bare wood fibers when exposed to the sun for extended periods of time.

We like to compare pigmented wood finishes to sunblock. Your body’s natural reaction when exposed to the sun over time is to tan or burn, it’s just how your body manages UV exposure. You apply sunblock to create a protective layer between you and the sun.  When you apply a wood finish that contains pigments or tints, you are accomplishing the same thing as you are with applying sunblock before you go to the pool, which is to provide a layer of pigment protection between the wood and the sun.

Semi-transparent, tinted wood finishes provide your wood with UV protection. Different wood finish brands contain various UV inhibitors, but the rule of thumb is the darker the tint of the stain, the better the UV protection for your house.  If your house is located in a high sun area, where it is fully exposed for hours at a time, LogFinish.com recommends using a finish with a medium to dark tint.

If your deck or wood exteriors are weathered and gray and you have decided to re-finish them with a tinted product it is important to first remove the gray, weathered surface. To do this, we recommend using a cleaning and brightening product that will leave your wood at the proper pH for staining as well as remove any dirt and pollen that has collected on the wood.  We do not recommend using household bleach and water to brighten wood because of its ability to dramatically change the natural pH of the wood. Instead, try out an oxalic acid based product like X-180 Weathered Wood Restorer, a wood cleaner and brightener for mild to severely discolored wood.

Thanks to the good folks at Perma-Chink Systems and LogFinish.com for inspiring this article and providing a wealth of information on this subject.

What You Should Know Before Using a Clear Wood Finish

Our customers often ask us for a clear or “natural” finish that will protect their wood.  The truth is, clear finishes may provide water repellency, resistance against mold and mildew and insecticidal properties.  However,  clear finishes do not  protect your log home from UV rays that cause weathering and graying of your home’s exterior, decks and rails.  With most clear finishes you will notice graying wood within 1-2 years of initial application.

Why will the exterior of your home turn gray if you only use a clear finish to protect it?   UV rays break down the lignan fibers in the wood which in turn causes the wood to gray.  

Semi-transparent, tinted wood finishes provide your wood with UV protection.  Different stain brands contain various UV inhibitors, but the rule of thumb is the darker the tint of the stain, the better the UV protection for your house.  If your house is located in a high sun area, where it is fully exposed for hours at a time, LogFinish.com recommends going using a finish with a medium to dark tint.

If your deck or wood exteriors are weathered and gray and you are looking to clean them up, re-stain and bring the wood back to it’s natural color, we recommend using an oxalic acid based product like X-180 Weathered Wood Restorer from American Building Restoration.  This product is a wood cleaner and brightener and will take the gray out of lightly to severely discolored wood.

Another option for cleaning gray, weathered wood is oxygen based detergent and brightening cleaners like All Wood Cleaner from New Image Coatings.  This is cleaner has very low environmental impact, can be used safely over water and will not harm plants.  All Wood Cleaner harnesses the power of oxygen to clean and brighten wood without harsh chemicals.

When cleaning your deck or exterior wood we do not recommend using bleach.  Bleach can cause streaking, spotting and even break down wood fibers.

 

New Exterior Stain from Perma-Chink Systems

 Perma-chink Systems, Inc., has released a new two-coat only exterior wood finish that is amazing for many different reasons.

Appearance+Longevity

1. Ultra 7‘s state-of-the-art resin ensures that the seal is continuous, providing protection from holes and gaps that might otherwise develop with a lower-quality finish.  What is a polymer resin?  A polymer resin is a clear liquid plastic product that hardens to create a thick, durable, glossy coating. Once hardened, polymer resin is fade-proof and water-resistant (1).

 2. Ultra-7’s water-resistant film breathes just like Gore-Tex® to allow trapped moisture to evaporate from your logs.

 3. Ultra-7 includes transparent oxides (sunscreen for your wood) and mildew inhibitors to protect against UV degradation, color fading and mildew collection on your home.

  •  Value+Environment

1. Ultra-7 can be used in nearly every application around your home, making it a great one-stop shop product for all of your finishing needs. It works on exterior walls, decks, railings, siding, while also being compatible with all existing Lifeline coatings to help streamline your maintenance routine.

2. Perma-Chink Systems is offering up to a 5-year warranty against UV exposure when applied to bare wood and covered with Lifeline Advance clear topcoat. Click here for more details.

3. Easy clean-up!  The tools you use to apply your home’s finish need only soap and water for clean-up, eliminating the need for any harsh chemicals during the initial application or maintenance.

4. Ultra-7  meets and exceeds all standards for low-VOC exterior finishes in the most restrictive regions in North America.

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So there we are.  Lifeline Ultra 7 is supported by a 3 year warranty against UV degradation, it is a two-coat only system finishing with a one coat of Lifeline Advance gloss or satin which increases durability, and can be used for multiple applications around the home!  Whats not to like?  Please let us know your experiences with Ultra-7 in the comments below so we can develop a good understanding of the performance and usage of Lifeline Ultra-7 in the industry.  Please keep in mind that you do need to register your home with Perma-Chink Systems, Inc., in order to qualify for the warranty.

 

Thank you to Perma-Chink Systems, Inc. for providing information for this post.  Want to see Lifeline Ultra 7 colors and read more? Visit www.LogFinish.com or give us a holler for some friendly help at 1-888-208-2248.  Ready to finish your home?