Key Takeaways
- Wash media blasted wood with Log Wash before staining to remove dust, blasting media, mold spores, and other material left on the surface.
- For media blasted wood, Perma-Chink Systems recommends mixing Log Wash at two cups per gallon of clean water.
- Blowing off the surface with compressed air does not replace washing because dust, old finish residue, and other contaminants can remain on the wood.
- If more than seven days pass after chemical cleaning, wash the bare wood again with Log Wash before applying stain.
If a home has been media blasted, is it really necessary to wash down the wood with a Log Wash™ solution before it is stained? We believe it is and here’s why. If corncob grit or walnut shells are used, and you take a close look at a blasted wood surface, you will find lots of particles embedded in the wood. Along with the particles are invisible mold spores that can germinate and feed on these biodegradable media sources.
To prevent mold spots from developing under the stain, these mold spores need to be removed, preferably by washing the surface with a solution of Log Wash (2 cups per gallon of clean water). Even if glass, dry ice, or other types of blasting media are used, we still recommend washing down the blasted surface to remove any remaining foreign matter that may be adhering to or embedded within the wood.
Blowing high-pressure air on the wall will not completely remove all of the dust and old finish residue. Without washing the surface, you run the risk of compromising the adhesion of the new finish.
On the other hand, most chemical strippers and cleaners do a good job of eliminating mold spores and dust particles, which is why it may not be necessary to use Log Wash if the home is going to be stained within a few days of stripping or cleaning. However, if the stain application is delayed more than seven days after the wall has been chemically cleaned, apply a Log Wash solution mixed at two cups per gallon, rinse thoroughly, and allow the wood to dry before applying the stain.
It only takes a few days for enough mold spores, pollen, and dirt to accumulate on bare wood to create a problem.
Perma-Chink Systems recommends thorough cleaning and preparation because careful surface preparation helps prevent unsightly fungal growth beneath the finish and supports the adhesion and longevity of exterior stain and topcoat systems. For more information about preparing stripped wood, see our Clean and Restore recommendations.
Frequently Asked Questions
Do you need to wash logs after media blasting?
Yes. Perma-Chink Systems recommends washing media blasted wood with Log Wash before staining. Washing removes dust, old finish residue, embedded blasting media, mold spores, and other contaminants that compressed air can leave behind.
How much Log Wash should I use after media blasting?
For media blasted surfaces, mix Log Wash at two cups per gallon of clean water. Rinse the wood thoroughly after washing and allow it to dry before moving forward with the stain or primer specified for your finish system.
Is compressed air enough to clean wood after media blasting?
No. Compressed air removes loose dust and debris, but Perma-Chink Systems recommends washing afterward to remove remaining dust, loose wood fibers, blasting residue, and other contaminants before finishing.
What if the logs were chemically stripped instead of media blasted?
Chemical strippers and cleaners can remove mold spores and dust during the stripping process. If you plan to stain within a few days, another Log Wash application may not be necessary. If more than seven days pass after cleaning, Perma-Chink Systems recommends washing the surface with a two-cups-per-gallon Log Wash solution before staining.
Prepare the Wood Before You Stain
Shop Log Wash for preparing bare wood before staining, or review Perma-Chink Systems’ Clean and Restore resources for more surface-preparation guidance. If you’re considering media blasting but don’t have experience with the process, Find a Contractor Near You or call Perma-Chink Systems at 1-800-548-3554 to discuss your surface-preparation options.
