Easy dose it: gently remove the coating or stain
Going slowly will reduce the need for sanding any raised grain (fur) after the stain or coating is rinsed away. Yes, rinsed away. Using a power washer correctly will work well to remove the existing product.
A word on power/pressure washers
Used properly, a power washer can effectively clean and maintain the wooden surface of your deck. Unfortunately there are many who use a power washer without knowing how it works.
First, it is not the PSI that gets the job done…it’s the GPM (gallons per minute).
Second, the power washer is a water broom not a water chisel.
Third, the machine maybe two tools in one…a water broom and a products (soap) applicator.
In closing, a tool used properly will yield positive results. Some claim power washers “inject” water into the wood fiber, permanently damage or in other ways render wood unable to finish, to those claims I say again, “a tool used properly will yield positive results.”
What coatings dissolver/stripper to use
There are many products on the market today for removing/stripping coatings or stains from your deck. I will say here and now that “Wood refinishing of cabinet doors or dresser drawers is nothing like refinishing wood out of doors.”
Hot solvent strippers like methylene chloride work well on interior projects but lack the staying power for exterior use. When you consider temperature, the drying effects of wind, hot solvents gas off too quickly for most applications.
Products with high a pH or solvents that have a slow evaporation rete are called for. However and for whatever product you choose, you need to determine product suitability, dwell time and application procedure.
Thicker viscosity products will offer you a longer dwell time. Often you may find that the product cuts through the coating quickly. If this is the case, look to see if the manufacturer offers a liquid version of the product. Also, read the directions and see if the liquid product can be diluted with water. If it can, it makes the product that much more economical.
Before beginning the overall operation TEST to determine
- Product suitability
- Dwell time, and,
- Application procedures.
Once you have determined what product to use and how long it will have to sit on the surface to remove the coating to your satisfaction, begin.
Don’t bite off more than you can chew
Look at the overall project and break it up into manageable segments. Vertical, horizontal, large and small, are aspects to consider when you begin the removal process. Some tomes it’s best to work from the outside, in. The railing, spindles and fascia board can be treated first allowing for any over spray or drips to land on the decks walking surface. The walking surface is last to be done. WARNING! Deck floors treated with strippers maybe very slippery. Take care when walking on treated areas. Treat an area no larger than you have time for. If the product allows, mist it with water so it will not dry out. If you have to cover with plastic make sure the stripper stays active by checking for drying. Again mist with water or apply more stripper.
Now that the coating has been removed
Once you have successfully stripped your deck, look over the woods surface for raised grain or dark, discolored areas. If the stripper you used requires neutralizing, the application of a neutralizer will often brighten and make the surface ready for staining. If you have raised grain and sanding is a must, use 60-80 grit paper to sand the wood. Do not sand too smooth.
NO “SAND THE FLOOR”
It was a cool movie when it came out. The old Japanese guy, teaching the Kid karate by doing manual labor, saying stuff like, Wax on, wax off.” Neat… But sand the floor? Not gunna duit. Don’t sand if you don’t have to. Over sanding or smoothing out the surface can work to close the grain and interfere with adhesion or penetration of the finish you choose.
Allow the stripper to do the work
Let the paint/stain remover you’ve chosen do the work of lifting and dissolving the coating from the woods surface. Brute force will only make more work for you. Most coatings removers are not cheap. Don’t waste your money by rushing the process. By your test you have determined the dwell time so…let it dwell.
And again easy with the PSI, remember a power washer, it’s a water broom, not a water chisel or worse, grinder.