I have heard alot about cleaning wood with caustic. What is a good caustic mixture to use? I assume the ones using caustic are mixing their own solutions to clean with. Any help or advice greatly appreciated.
I have heard alot about cleaning wood with caustic. What is a good caustic mixture to use?
After the application of the stripper, a low-pressure wash is needed, followed by the neutralizer. As for when to stain/seal, it depends on the weather, but 48 hrs is about right for my area of VA. Fences can usually be done in 24 hrs as they dry much faster.
Cleaning a deck (speaking about pt pine) usually involves emulsifying the top layer of dirt and the killing of mold/mildew/algae. Using either bleach/chlorine (diluted, of course) or a sodium hydroxide stripper allows for the use of low, or at least lower, pressure to clean.
A 20 year old deck that has never been maintained will have crusted-on green gunk (a technical term) that will likely require the use of bleach/chlorine. Dwell time is important, regardless of how or what you are cleaning and this knowledge will come with experience. I will say that when the label says to keep the stripper wet, a light misting of water is all that's needed - you don't have to keep reapplying stripper. If the stripper dries, simply misting will re-activate it.
Regardless of how you clean, neutralizing is a must. How strong mix of oxalic? The best way to tell is that when applied at the proper rate, the wood will almost immediately lighten in color. Neutralizing must be done to stop the chemical reaction of the stripper/cleaner. If not done, the wood will tend to "fuzz". A too strong mix of sodium hydroxide will also tend to "fuzz" the wood.
Again, dwell time, strength of chem, pressure used and proper neutralizing as well as washing technique (its all in the wrist action!) all affect the outcome, so it's best to practice - on your on deck if possible.
I have helped local pwers with washing/stripping decks and fences. I'll extend that offer here as well. My phone is always on.
* In all fairness, I don't consider myself a "woody". I wash houses and many of my customers have decks - mostly PT Pine - and want to keep them looking nice. In 10 years, I have used a sander a few times, replaced a few boards and pounded more than a few nails but I don't consider myself a deck restoration expert...though my customers are always satisfied with my work and refer me constantly. I have many decks that I have been maintaining for years, so I know how to do what I do and don't mind sharing.