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.
Thermac Ash Light Roast — CUTEK® Extreme Clear Finish
Thermac Ash Light Roast is a thermally modified White Ash produced by Bingaman & Son Lumber, one of the leading domestic manufacturers of thermally modified hardwoods in North America. Sourced from responsibly managed Appalachian and Pennsylvania forests, the ash is transformed through a chemical-free process that uses only heat and steam — no chemicals, plastics, or additives — sustained for 14–16 hours in an oxygen-deprived kiln. The "Light Roast" designation refers to a lower peak modification temperature, producing a warm caramel-to-amber tone rather than the deeper chocolate brown of a standard or dark roast. The result is a domestic hardwood with the color character of exotic species like teak or light walnut, while retaining more of ash's natural grain contrast and figure.
The performance story is where thermally modified ash really shines. The modification process breaks down the sugars and hemicellulose that fungi and insects feed on, and permanently reduces the wood's ability to absorb moisture — by as much as 45% compared to untreated ash. Independent testing per EN 350 standards rates thermally modified ash at Durability Class 1 ("very durable"), placing it in the same durability tier as tropical hardwoods like teak and ipe, with an expected exterior service life of 25+ years. Dimensional stability improves dramatically as well: radial and tangential shrinkage drop to under 1%, virtually eliminating the cupping, warping, and seam-opening that plague untreated ash outdoors.
Each board is finished with CUTEK® Extreme Clear, a penetrating oil engineered to stabilize exterior wood from the inside out. Rather than forming a surface film like paint or varnish, CUTEK® 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. The clear formulation adds no pigment, allowing the Light Roast's warm caramel tone to show through initially before gradually silvering to a soft gray patina if left unmaintained with a colortone.
Ideal for high-end exterior siding, cladding, soffits, porch ceilings, feature walls, and covered outdoor living spaces where the warmth of a lightly roasted domestic hardwood is preferred over the deeper tones of standard thermally modified ash.
Specifications
| Spec | Detail |
|---|---|
| Species | White Ash (Fraxinus americana) — thermally modified |
| Product Line | Thermac by Bingaman & Son Lumber |
| Modification Level | Light Roast — lower-temperature thermal modification for lighter tone |
| Origin | Appalachian / Pennsylvania hardwood, USA |
| Modification Process | Heat and steam only, no chemicals; oxygen-deprived kiln for 14–16 hours |
| Finish | CUTEK® Extreme Clear (penetrating oil) |
| Finish Type | Oil-based, non-film-forming |
| Color | Warm caramel-to-amber 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 |
| Janka Hardness | ~820–1,325 lbf (varies by modification intensity) |
| Dimensional Stability | Radial shrinkage ~0.1–1.0%; tangential ~0.4–1.0% — significantly improved vs. untreated ash |
| Density | ~554 kg/m³ post-modification (roughly 12% lighter than untreated ash) |
| Equilibrium Moisture Content | ~4–6% (vs. 18–22% for untreated ash) |
| Water Absorption | Reduced 60–70% vs. untreated ash |
| Service Life | 25+ years in exterior applications with proper maintenance |
| Fire Rating | Class B/C flame spread achievable (ASTM E84) |
| Applications | Exterior siding, cladding, soffits, porch ceilings, feature walls, decking, trim |
| Fixings | Stainless steel recommended; pre-drilling advised near board ends |
| Maintenance | Clean and re-oil with Cutek Extreme as needed — no sanding or stripping required |
| Sustainability | Domestic hardwood from sustainably managed forests; chemical-free modification |
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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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