Mark, thanks for the detailed and informative response. I learned a great deal from your post.
Based upon your experiences, can you share some recommendations regarding the best (ie most durable) exterior stain products for wood? Please include products sold commercially, as opposed to only at the local BORG's.
Thanks.
Scott
I have used products made by Phillips, Sherwin Williams, Pittsburg, TWP, Cuprinol and Wohlmans. None lasted more than 3 years in direct sun without significant coating deterioration. (loss of moisture and mildew resistance, pigmented stains were chalking and mostly gone). The Phillips and Sherwin Williams had wood deterioration beginning in that time. The Cuprinol copper based coating (green) for wet wood areas did work well for up to about 7 years. I would say that I had best results from the Pittsburg and Cuprinol .
No transparent coating made it past two years (most were mostly gone after one) and the translucents were only slightly better. (Most of what I used and/or evaluated was in FL and other southern climes (Pacific Islands, Cal, Arizona, NM, La, Texas, etc so some extended life can be expected this far north).
In well shaded areas, there was a lot less chalking, but they still lost a lot of the moisture and mildew resistance.
IMHO, if you want to see the wood grain, plan on recoating every other year in the sun, and every third year in the shade.
If you are going with opaque route, a good quality acrylic latex (the $20+ per gal variety) will provide better and longer protection (about 7 years direct sun and 10+ in the shaded areas) at about the same materials cost, but will require initial priming and 2 coating. Repainting, if done before the wood is showing and water saturated, can be power washed and one coated. An opaque oil-based stain in the high foot-traffic areas on a deck would probably stay more attractive and be easier to refinish than latex, but it will need doing every 3 years or so, depending on exposure. I would not use a floor & deck enamel on an open PT deck, as the moisture from underneath will cause the enamel to peel. I have used the cheap "barn paint" from Lowes on handicap ramps and they are still holding up well after 2+ years, probably because the wood sucked up the paint about as fast as I could apply it.
I have not used Penofin, Rhinogard, Ready Seal, or Cabots. They have gotten good reviews, but all still recommend recoating in 2 -3 years, and I have not heard of them lasting any longer anywhere this far south.
Sorry if this doesn't answer the question, but the word durability and exterior stains have not gone together in my experience..
Go:wsad: