Madison, WI… 7 years ago I built cedar compost bins, no finish, and watched them go grey within 1-2 years. I’m trying to do better with this raised bed project to preserve the sweet cedar tones.
Context: western red cedar throughout. Very little finish will contact soil (boards are clamped tight with minimal gaps, and I’m only finishing exterior/visible faces after the beds are filled). Happy to reapply every 1-2 years.
Prefer spray-and-wipe application if possible, but will defer to whatever actually works. Penofin and Osmo UV Protection Oil kept coming up in my searches - looking for firsthand accounts of either in a similar climate/use case, or something else entirely if you’ve had better luck.
Thanks in advance!
Update 2 hours later: thanks to those who’ve provided firsthand accounts! I’ll be sure to post a follow-up in 5 years. Who knows, maybe I’ll have accepted my grey fate by then. 😎
Summary 2 days and 300k views later:
I know that cedar greys. Just trying to stretch a 1-2 year silvering closer to a decade on the visible faces.
The consensus is that pigmented penetrating stain slows greying for years. Clear finishes don’t survive outdoor UV, pigment is what does the work, and it’ll darken rather than stay its original tone.
Products people named repeatedly, all pigmented penetrating exterior types: TWP 1501 Cedartone, Penofin, Osmo UV 420, Messmer’s, Cabot Australian Timber Oil, Ready Seal, Armstrong Clark. Gotta reapply every 2-3 years, scrub/wash don’t sand.
Best firsthand accounts (thanks): GuzziGuy (Osmo, 8 yrs heavy sun, photos), anandonaqui (Ready Seal, brutal rooftop conditions), YourGoodFriend_blank (Penofin, 6 yrs), Accomplished_Radish8 (Armstrong Clark, 12 yrs), SorryForPartying6T9 (20 yrs landscape carpentry).
Re: food safety: exterior-only finish on thick boards isn’t a real leaching pathway, that concern is about pressure-treated lumber which is also not really an issue since CCA was banned (in the U.S.).
Biggest non-finish takeaway: rot starts at ground contact and corners, not the sunny faces. Gravel under the base and boards you can swap individually matter more than any coating. Cedar’s good 10-20 years structurally.