CUTEK®
Mason’s Mill & Lumber stocks the complete CUTEK® system — CUTEK® Extreme clear oil, CUTEK® Colortones, cleaners and applicators — plus CUTEK® pre-finished wood milled right here in-house.
Wood protection, passed down through generations
CUTEK® loves the look and feel of wood, and sets out to provide the best wood protection solutions on the market. The company is passionate about the sustainability of the lumber industry — without wood, there would be no need for wood oils.
As a family business passed down through generations, CUTEK® is committed to helping the lumber industry thrive for generations to come.
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The CUTEK® system is built around two simple steps: Prepare and Protect. Start with CUTEK® Wood Stripper and/or CUTEK® Wood Reviver to get your wood clean and ready. Then protect it with CUTEK® Extreme clear oil, adding a CUTEK® Colortone to maintain or change the color. Then maintenance is as easy as a wash with CUTEK® Quickclean and a re-coat with CUTEK® Extreme, no sanding required.
Thermory Benchmark Ash — Vivid Walnut Stain Finish
Thermory Benchmark Ash is the flagship hardwood product in Thermory's cladding and decking lineup — a thermally modified White Ash that sets the benchmark for what modified domestic hardwoods can achieve in exterior applications. Sourced responsibly from naturally renewing North American and Northern European forests, the ash is transformed through Thermory's proprietary "Intense" thermal modification process at 215°C (419°F) using only heat and steam. No chemicals, plastics, or additives are introduced at any stage — the transformation is purely physical, altering the wood's cell structure to permanently eliminate the food source for fungi and insects while dramatically reducing the board's ability to absorb moisture.
The result is a stunningly beautiful hardwood with an exotic, deep chocolate-brown color that runs consistently through the entire board — not a surface stain that can chip or wear away. Because the color is produced by molecular caramelization during modification, whenever the board is milled, cut, or sanded, the same rich brown tone remains visible. Thermory Benchmark Ash carries Durability Class 1 ratings under EN 350 — the highest possible durability class — with proven rot resistance for 25+ years in exterior applications, placing it in the same durability tier as tropical hardwoods like teak and ipe, but sourced sustainably from managed North American and European forests.
The performance advantages are substantial: equilibrium moisture content drops to just 4–7% (versus 18–22% for untreated ash), radial and tangential swelling are cut to under 3%, and Janka hardness measures approximately 4,450 N. Because the wood is naturally hydrophobic post-modification, it twists, cups, and bends significantly less than untreated hardwood — critical for the tight, gap-free seams demanded by modern architectural cladding profiles.
Each board is finished with Vivid Walnut Stain, a penetrating oil engineered to stabilize exterior wood from the inside out. Rather than forming a surface film like paint or varnish, Vivid carries its oils deep into the wood fibers, where they work continuously to slow moisture movement — the primary cause of cupping, checking, and end-splitting. Because the finish penetrates rather than coats, it cannot peel or flake, and maintenance requires no sanding or stripping — just clean the surface and reapply when it looks dry.
Ideal for premium architectural siding, cladding, soffits, porch ceilings, feature walls, decking, and porch flooring where the aesthetic warmth of exotic hardwood is desired alongside the sustainability and performance credentials of a domestically modified species.
Specifications
| Spec | Detail |
|---|---|
| Species | White Ash (Fraxinus americana / Fraxinus spp.) — thermally modified |
| Product Line | Thermory Benchmark Ash |
| Modification Level | Intense — 215°C (419°F) thermal modification, heat and steam only |
| Origin | North America and Northern Europe (sustainably managed forests) |
| Finish | Vivid Walnut Stain |
| Finish Type | Oil-based, non-film-forming |
| Color | Rich, exotic chocolate brown; consistent through full board thickness |
| Weathering | Silvers to gray patina over time if not maintained with colortone |
| Durability Class | Class 1 ("very durable") per EN 350 — highest possible rating |
| Use Class | 3.2 — exterior, above ground, exposed to prolonged wetting conditions (EN 335) |
| Fire Rating | D-s1, d0 (EN 13501-1); Class B flame spread achievable per ASTM E84 |
| Janka Hardness | 4,450 N (~1,000 lbf) |
| Brinell Hardness | 35.6 N/mm² |
| Bending Strength (MOR) | 58.6 N/mm² |
| Modulus of Elasticity | 15,535 N/mm² |
| Compressive Strength | 80 N/mm² |
| Oven-Dry Density | 581 kg/m³ |
| Initial Moisture Content | 6.7% ± 2% |
| Equilibrium Moisture Content | 4% at RH 35%; 6.6% at RH 60%; 10.9% at RH 90% |
| Radial Swelling (35→90% RH) | 0.9% → 2.9% |
| Tangential Swelling (35→90% RH) | 1.6% → 3.3% |
| Screw Traction Resistance | 29.9 N/mm² |
| Grade | Select |
| Warranty | 25+ years rot resistance (Thermory) |
| Standard Lengths | 0.8 – 3.9 m (cladding); 0.8 – 3.9+ m (decking) |
| Applications | Premium exterior siding, cladding, soffits, porch ceilings, feature walls, decking, porch flooring, architectural millwork |
| Fixings | Stainless steel required (FG Screws or PaCS Clad clips recommended); pre-drilling advised |
| Maintenance | Clean and re-oil with Cutek Extreme as needed — no sanding or stripping required |
| Sustainability | Chemical-free modification; sustainable alternative to tropical hardwoods; sourced from managed forests |
| Environmental | EPD available; GWP-Biogenic A1-A3: -5.66E1 kg CO₂e/m³ (net-negative embodied carbon) |
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Learn More About CUTEK®
See CUTEK® in action. These short videos show how the CUTEK® 2-step system works, from preparing your wood to applying CUTEK® Extreme clear oil and CUTEK® Colortones, so you can take on your project with confidence.
Ask about Mason's Mill CUTEK® Pre-Finished Wood! Contact us for a free quote!
Retain Your Wood's Color
With CUTEK® Colortones you can enhance and maintain the natural beauty of your wood, or alter the color to meet the design requirements of your project. Colortone swatches are shown below in groups of Brown Hues, Red Hues, Yellow Hues and White/Black Hues.
Shop CUTEK® Samples
Revive, Strip or Clean Stained& Weathered Wood to Original Appearance
With the CUTEK® Wood Reviver, Wood Stripper and Quickclean products, you can brighten, clean and restore wood to look like new and prepare for CUTEK® Extreme with CUTEK® Colortone Pre-Mixed Stains. These powerful yet safe CUTEK® wood enhancing products are user-friendly, DIY-friendly and no professional experience is necessary. – CUTEK® needs to be added before the name of each of our products.
Frequently Asked Questions
Traditional varnishes and many "penetrating" oils form a film on the surface of the wood. Over time, UV rays and wood movement break down that film, causing it to flake or peel and letting water in, which leads to cupping, warping, splitting and rot. CUTEK® Extreme clear oil is a true penetrating oil. It diffuses deep into the wood and drives moisture out from the inside. Its protective components stay permanently mobile in the wood, migrating to any cut or fastener hole and sealing it against moisture. This "self-healing" effect is what makes CUTEK® the professional's choice for long-term wood protection.
Step 1 – Prepare: Clean and enhance your wood with CUTEK® Wood Reviver, CUTEK® Wood Stripper or CUTEK® Quickclean. Step 2 – Protect: Apply CUTEK® Extreme clear oil, with a CUTEK® Colortone added if you want to hold or change the color of your wood.
No. CUTEK® Extreme will not peel or flake. Over time, wood exposed to the sun will fade and a CUTEK® Colortone can wear with use. When that happens, simply clean and apply a maintenance coat — no sanding or stripping required.
Yes. CUTEK® Extreme stabilizes wood by controlling the free exchange of moisture between the wood and the environment. Because it stays mobile and self-healing, that protection continues even when the wood is cut or fastened, improving dimensional stability and extending service life.
Yes. Each additional coat of CUTEK® Extreme adds more protection against moisture. The more consistently you maintain your wood with CUTEK® Extreme, the better protected it becomes.
No. CUTEK® Extreme must be applied to bare, clean and dry wood. Existing stains, paints, linseed oil, polyurethane and water-based finishes block penetration and must be fully removed first with CUTEK® Wood Stripper followed by CUTEK® Wood Reviver, or by machine sanding.
CUTEK® Extreme can be applied to new wood without preparation. For the best results — and especially if you're adding a CUTEK® Colortone — we recommend CUTEK® Wood Reviver first to clean the surface, open the grain and remove tannins, mill glaze and other stains.
Use CUTEK® Wood Reviver. It removes the grey and brings back the original color and grain of your wood before you apply CUTEK® Extreme.
Clean it with CUTEK® Quickclean to remove dirt, grease and grime, then recoat. If maintenance has been neglected and the wood has greyed or become heavily stained, use CUTEK® Wood Reviver before recoating.
Stir CUTEK® Extreme thoroughly from the bottom of the can (with your CUTEK® Colortone mixed in, if using) before and during use. Apply thin, even coats with a brush or paint pad applicator. Two or three thin coats are much better than one or two thick coats.
Yes. Wood coated with clear CUTEK® Extreme can be installed immediately or block stacked wet for later use. We don't recommend wet stacking wood coated with a Colortoned CUTEK® Extreme, as it may create an uneven, smudged finish.
Request a CUTEK Quote
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