CUTEK® Extreme is a true penetrating exterior wood and deck oil — not a stain, and not a sealer in the traditional sense. Instead of building a film on top of the wood, it diffuses deep into the fiber and stays mobile there, which is why it won’t peel, crack, or flake the way surface coatings eventually do. It’s formulated for decks, siding, fences, and pergolas, and it performs especially well on hardwoods like Ipe and Cumaru that resist traditional finishes.
CUTEK® Extreme is available clear, which lets wood weather naturally to a silver-gray patina, or mixed with one of 18 CUTEK® Colortones for UV protection and richer, longer-lasting color. Not sure which route to take, or how to prep your wood first? See our How CUTEK Works guide and wood prep guide — and if your project needs a cleaner or stripper before the first coat, check out the full CUTEK Extreme & Prep Products lineup.
Frequently Asked Questions
Is CUTEK® Extreme a stain, a sealer, or an oil?
It’s a penetrating wood oil and stabilizer. Unlike a stain or sealer, it doesn’t form a surface film — it diffuses into the wood fiber to control moisture from within, which is what allows it to fade evenly instead of peeling or cracking.
Can I use CUTEK® Extreme on siding and fences, or is it just for decks?
It works well on any exterior wood surface, including decks, siding, fences, and pergolas. The oil’s penetrating, self-healing properties benefit vertical and horizontal surfaces alike.
Does clear CUTEK® Extreme still protect the wood, or do I need a Colortone?
Clear CUTEK® Extreme protects the wood fully on its own. Without a Colortone added, the wood will simply weather to a natural silver-gray patina over time rather than holding its original color.
How often will I need to reapply?
Most projects need a maintenance recoat every 6–12 months, depending on sun exposure and foot traffic. Because the oil fades evenly rather than peeling, reapplication is a clean-and-recoat job — no stripping or sanding required.
Will CUTEK® Extreme work on a deck that’s never been oiled before?
Yes, new or bare wood is an ideal starting point. If the deck has mill glaze, old coatings, or years of weathering, prep it first — see our prep guide to find out whether you need a brightener or a stripper before applying.