Wood Finishes – Water Repellency Test Results
The Latest Independent Wood Finish Test Results as of 11/2000
NOTE FROM TIM CARTER - Founder of AsktheBuilder.com - posted October, 2016: I no longer would apply Defy deck sealer to any exterior wood that I own at my own home.
The information below is very dated and what's more, just about all deck sealers will look good after six months. In 2012, I began an extensive test of my own on many popular deck sealers. CLICK HERE to read about this test. TC
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On November 1, 2000, the Earlham Analytical Testing Labs located in Richmond, Indiana started a weathering test of 30 penetrating wood finishes. To make sure apples were being compared with apples, only penetrating semi-transparent finishes were tested. This is important! In other words, clear finishes that contain little UV protecting pigments were not included in the study.
It is not uncommon for the testing procedure to look at the samples after six months and then continue on with the testing until certain products begin to fail. Preliminary results of this ongoing, independent testing on penetrating semi-transparent wood finishes indicates that the products listed below are ranked in the top five, based on performance in ASTM water repellency testing and six months of outdoor exposure. The five products listed in alphabetical order are:
- DEFY Penetrating Water Repellent Wood Finish manufactured by SaverSystems is a water-based, synthetic resin formula. Defy comes in a range of colors which are illustrated on their web site.
- F & P Premium Wood Finish manufactured by Wolman Wood Care Products is an oil-based formula.
- Sikkens Cetol SRD manufactured by AKZO Nobel Coating, Inc. is an oil-based formula.
- Storm Stain Linseed Oil Alkyd Decking Stain manufactured by California Products Corp. is an oil-based formula.
- TWP Total Wood Preservative manufactured by Gemini Coatings, Inc. is an oil- based formula.
These are the six months preliminary results as of 2001. For an update on this topic, read my column on Clear Epoxy Deck Cleaner.
Synthetic Resins vs. Natural Oils
Only one of the top five performers is a synthetic resin based product. Natural oil products often become food for mildew and algae once the mildewcides and fungicides in the finishes are damaged by sunlight and/or dissolved away by repeated rainfall or snow melt. This may be the biggest reason your past deck finishes have turned black or green. The mildew and algae were actually eating your deck finish. This is often not a problem with synthetic resin finishes.
No matter what product you choose to use, read the directions and follow them closely. I have personally used Defy on my wood porches over the years and have had great success. Many, many past readers of my columns and bulletins have also had huge success with Defy. I get phone calls, emails and letters with photos on a regular basis from homeowners just like you that love the performance of Defy. Remember, follow directions of any of the above products to get long lasting results.
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