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1. Product Description

Durabak-18 Outdoor / UV is a single-component, moisture-cured aliphatic polyurethane coating containing recycled-rubber granules (Textured grade) or cast as a smooth film (Smooth and White grades). The curative is isophorone diisocyanate (IPDI, CAS 4098-71-9), an aliphatic isocyanate that resists UV degradation without chalking or yellowing -- the property that distinguishes Durabak-18 from Durabak Indoor, which uses an aromatic MDI curative and is not suitable for sustained sun exposure.

The coating cures by reaction with atmospheric moisture and releases carbon dioxide as a by-product. No mixing, no catalyst, and no pot-life countdown are required for normal use. An optional accelerator (sold separately) shortens cure time. The cured film is abrasion-resistant, slip-rated in Textured grades, fuel- and chemical-resistant, and bonds to most prepared substrates.

Formulation type: One-part (single-pack) moisture-cured aliphatic polyurethane.

Curative: IPDI (aliphatic; UV stable).

Finish options: Textured (recycled-rubber granules) | Smooth | White.

2. Recommended Uses and Features & Benefits

Primary applications

• Truck bed liners (roll-on or brush)
• Marine decks, boat hulls below the waterline, dock surfaces
• RV roofs and exterior panels
• Automotive undercoating and wheel-well protection
• Industrial and commercial floors subject to foot traffic, vehicle traffic, and chemical exposure
• Any outdoor surface requiring a durable, UV-stable, slip-resistant finish

Features and benefits

Feature	Detail
UV stable	Aliphatic IPDI curative; resists chalking and yellowing under prolonged sun exposure
Slip-rated (Textured)	Recycled-rubber granules embedded in the wet film; ASTM D1894 / D2047 coefficients of friction on file
Abrasion resistant	Taber abrasion 30.5 mg weight loss at 1,000 g load / 1,000 cycles (ASTM D4060)
Chemical and salt resistant	100% salt-water resistance; salt-spray test no effect (ASTM B-117 / D-610); 7-day immersion data available (see Section 8)
One-part convenience	No mixing; moisture-cure; no pot life under normal use
Bonds to most substrates	Steel, aluminum, concrete, wood, fiberglass, rubber, rigid plastics, cured epoxy/primer
Spot repairable	Bonds to itself; recoatable after light abrasion
Elongation / flexibility	497% elongation (ASTM D2370); passes 1/8 inch mandrel bend with no cracking (ASTM D522)
Wide service temperature	-60 F to +254 F, including freeze-thaw cycling

Variant summary

Grade	Finish	Coverage (2 coats)	Slip-rated
Textured	Granule rubber texture	60 sq ft/gal (15 sq ft/qt)	Yes
Smooth	No granules; semi-gloss	75 sq ft/gal (18 sq ft/qt)	No
White	Smooth; white pigment	75 sq ft/gal (18 sq ft/qt)	No

Coverage is practical coverage at the rubber-granule textured profile; actual coverage varies with surface porosity and application method.

3. Product Data / Physical Properties

Composition (hazardous constituents above reporting thresholds)

Constituent	CAS	Approximate %	Notes
Xylene (mixed isomers)	1330-20-7	30-60%	Solvent carrier
Ethylbenzene	100-41-4	5-10%	Constituent of the aromatic (xylene) solvent
Isophorone diisocyanate (IPDI)	4098-71-9	(see SDS)	Aliphatic curative; UV stable

Physical properties

Property	Value	Test method
Type	One-part moisture-cured aliphatic polyurethane	--
Curative	Isophorone diisocyanate (IPDI, CAS 4098-71-9)	--
Liquid density	0.985 g/cm3 at 20 C (approx. 8.2 lb/gal)	ASTM D1475
Packaged weight (approx.)	approx. 10 lb/gal (filled container)	--
Flash point	27 C (80.6 F)	ASTM D56
pH	~8.0	--
Viscosity (product spec)	67-72 KU (Krebs)	--
Viscosity (uncured liquid, SDS)	80-110 KU (Krebs) at 20 C	--
Solids by weight	66%	per Navy F-718 + Durabak Tests & Data
Solids by volume	75.8%	--
VOC	250 g/L (2.08 lb/gal)	--
Boiling point	140 C	--
Decomposition temperature	200 C	--
Auto-ignition temperature	>200 C	--
Physical state	Liquid	--
Odor	Mild sweet / solvent	--
Service temperature	-60 F to +254 F (freeze-thaw cycling)	--
Gloss (Smooth grade)	~84.7%	--
Abrasion resistance	30.5 mg weight loss	ASTM D4060 (Taber, 1,000 g, 1,000 cycles)
Elongation	497% (ASTM D2370); passes 1/8 inch mandrel bend with no cracking (ASTM D522)	ASTM D2370 / D522
Shelf life (unopened)	12 months at 32-104 F	--

Wet film thickness (per coat): 17-25 mils.

Dry film thickness: 29-39 mils total (2 coats) (per Durabak Company datasheet).

Footnote: The Navy ASTM F-718 / SSPC-PA 2 dossier gives a measured alternative of 12-18 mils per coat; 24-35 mils total (2 coats).

4. Surface Preparation

Proper surface preparation is the single largest variable in adhesion and service life. Do not skip abrasion on any sound but glossy substrate.

By substrate

Substrate	Preparation required
Bare steel / iron	Remove all loose rust, scale, oil, and grease. Abrade to minimum SSPC-SP3 (power tool) or SP6 (commercial blast). Apply DuraPrime EP-90 epoxy primer or Zinc Phosphate primer before topcoat. Bare unprimed steel is not recommended for sustained immersion service without a primer.
Rusty or pitted steel	Wire-brush or grind to remove loose material. Spot-prime with Zinc Phosphate spray, then apply EP-90 over the full panel before Durabak-18.
Painted / sound-coated metal	Remove loose, peeling, or chalking paint. Scuff-sand the remaining sound paint to break gloss (80-100 grit). Wipe clean. Durabak-18 bonds to sound, abraded paint.
Aluminum	Degrease with solvent wipe. Scuff-sand (80-100 grit) or etch-prime with NS5 Metcote (dries 30 min at 77 F). Oxide layer must be removed or disrupted before topcoat.
Concrete	Clean, dry, and free of oil, curing compounds, and laitance. Acid-etch or grind to open the surface. Allow to dry fully (moisture reading). Concrete moisture content must be below the substrate-temp / dew-point limit stated in Section 5.
Wood	Dry (below 15% MC), clean, sanded to 80 grit. Knots and resinous areas: spot-seal with shellac or epoxy sealer.
Fiberglass / GRP	Degrease. Scuff-sand the gelcoat or existing finish (80-120 grit). Wipe off sanding dust. No primer required on well-abraded gelcoat.
Rubber	Clean and degrease. Light scuff with 80-120 grit. Durabak-18 bonds well to cured EPDM and neoprene.
Rigid plastics (most)	Clean, degrease, scuff-sand. Adhesion varies by plastic type; test an inconspicuous area. Polyethylene, polypropylene, and other low-surface-energy plastics: standard abrasion will not bond; flame/plasma treatment or a dedicated adhesion promoter is required, and a test patch is essential.
Cured epoxy / primer	Scuff-sand (120 grit) if more than 24 hours old. No additional primer needed.

What Durabak-18 will NOT bond to: glass; marble and polished stone; any non-porous, non-abraded surface that cannot be scuffed to a dull, open profile.

5. Application

Environmental conditions

Condition	Requirement
Ambient air temperature	32 F to 95 F
Substrate temperature	45 F to 90 F
Substrate-to-dew-point margin	Substrate surface must be at least 5 F above the dew point
Humidity	Normal ambient humidity drives cure. Avoid standing water or condensation on the surface. Higher humidity accelerates cure.
Standing water	Do not apply over wet or damp surfaces

Equipment

Method	Equipment / tip
Brush	Natural or synthetic bristle; suitable for cut-in, edges, and small areas
Roller -- Textured grade	Stipple roller sleeve (the stipple sleeve is required to key granules into the film; a standard nap roller will not work)
Roller -- Smooth grade	3/16 in short-nap mohair roller
Airless spray	Tip: 0.021-0.023 in; approx. 2.9 gpm class (e.g., Graco Bulldog 33:1)

Technique

1. Stir thoroughly before use. Do not shake the can -- shaking entrains moisture and air bubbles. Reseal the can immediately after each pour.
2. First coat: apply a uniform film at the wet film thickness target of 17-25 mils. Work in one direction. On textured grades, the roller action keys the granules into the wet film.
3. Second coat: apply after the first coat reaches the recoat window (see Section 7). Cross-coat direction (perpendicular to the first pass) improves uniformity.
4. Minimum 2 coats required to reach the specified dry film thickness of 29-39 mils total.
5. Accelerator (optional): add 1 packet of Durabak-18 Accelerator per quart or per gallon immediately before application. Mix thoroughly. The accelerator shortens cure time by up to 50% with no change to cured-film performance.
6. Working / open time after opening: approximately 3 hr at 25 C (4 hr at 20 C; 6 hr at 10 C). Reseal the can between coats.

6. Thinning / Reducer

Thinning is not required for most applications. If viscosity needs to be reduced for spray application or warm-weather brushing, use ONLY:

• Solvide reducer -- VOC-exempt; legal in all 50 states including California. This is the recommended reducer.
• Xylene / Xylol -- not sold to California or Utah residents. May be used in other states by operators who have confirmed local VOC compliance. (The VOC restriction applies to the xylene thinner product itself; the Durabak-18 coating VOC is 250 g/L regardless of reducer choice.)

Do NOT use generic lacquer thinner, acetone, MEK, or mineral spirits. These solvents are not approved reducers and can affect adhesion or cure.

Overthinning lowers the solids per coat and reduces dry film build. When thinning for spray, add the reducer in small increments and test on a scrap panel before applying to the work surface.

7. Dry / Recoat / Cure Schedule

Times are at 77 F (25 C) and moderate relative humidity (approximately 50% RH). Higher humidity and higher temperature accelerate cure. Lower temperature and lower humidity extend these times.

Stage	Time at 77 F / 50% RH
Tack / flash-off	1.5-3 hr
Touch dry	~1.5-3 hr
Minimum recoat (light tack)	~1 hr
Nominal recoat window	6-12 hr
Maximum recoat without abrasion	24 hr
Walk-on / dry-to-handle	6-12 hr
Full cure / return to service	4 days (full cure; allow longer at cooler temperatures or low humidity)
Working / open time after opening	~3 hr at 25 C; ~4 hr at 20 C; ~6 hr at 10 C

Maximum recoat note: if more than 24 hours elapse between coats, abrade the first coat lightly (120 grit) and wipe clean before applying the next coat. This restores mechanical adhesion.

Accelerator: reduces cure time by up to 50%. Full-cure timeline compresses proportionally; follow the recoat intervals as observed, not the clock alone.

8. Performance and Test Data

Physical and weathering performance

Property	Result	Test method
Abrasion resistance	30.5 mg weight loss (1,000 g load, 1,000 cycles)	ASTM D4060 (Taber abraser)
Slip resistance -- static CoF dry (Textured)	0.95-0.98	ASTM D1894
Slip resistance -- static CoF wet (Textured)	1.41	ASTM D1894
Slip resistance -- CoF dry (Textured, D2047 method)	1.21	ASTM D2047
Slip resistance -- CoF wet (Textured, D2047 method)	0.67	ASTM D2047
Smooth / White grades	Not slip-rated	--
Salt-spray resistance	No effect	ASTM B-117 / D-610
UV / weathering (500-hr QUV)	Gloss loss only; no cracking or checking	Internal test data
Flame spread index	01	ASTM E-162
Smoke generation	06	ASTM E-662
Service temperature	-60 F to +254 F	--
Water immersion	No effect (7-day)	ASTM D1308

Fire test note: the E-162 and E-662 values are tested results, not a fire rating. They do not constitute a UL or NFPA classification.

Chemical resistance (7-day immersion)

Results from the Durabak product manual immersion table. All results at 7-day exposure.

Chemical / medium	Resistance rating
Acids (general)	Excellent to Good
Alkalis (general)	Excellent to Good
Potable water	Not certified or suitable for potable-water contact or potable-water submersion.
Salt water	Excellent
Diesel fuel	Good
Gasoline	Fair
Concentrated chlorine	Discolors if not rinsed promptly -- rinse immediately
Acetone	Poor

"Excellent" = no effect on film. "Good" = minor or no visible effect. "Fair" = minor softening or discoloration on extended exposure; film recovers on drying. "Poor" = significant softening or swelling; avoid prolonged contact.

9. Clean-Up

Uncured material: clean tools and equipment immediately after use with xylene / xylol or Solvide. Once the coating cures, it cannot be dissolved by common solvents.

Cured overspray or drips: mechanical removal (scraping, sanding) only.

Skin contact: remove uncured coating with waterless hand cleaner or Solvide, then wash with soap and water. Do not use xylene as a skin wash. Cured film on skin will wear off over time.

Disposal of spent solvents and rags: comply with local hazardous-waste regulations. Rags and applicators soaked with solvent-thinned coating are combustible -- spread flat outdoors to dry before disposal, or treat as flammable waste.

10. Storage and Shelf Life

• Shelf life (unopened): 12 months from manufacture date, stored at 32 F to 104 F.
• Storage: store sealed in a cool, dry location at 32 F to 104 F. Keep away from heat, sparks, and open flame.
• After opening: moisture cure begins once the can is opened. Reseal promptly and firmly after each use. Purging the headspace with dry nitrogen or argon before resealing extends the in-can life of a partially used container.
• Do not freeze. Freezing will damage the product.
• Signs of degradation: significant viscosity increase, skinning, or gelatinous texture in an opened can indicates moisture contamination; do not use.

11. Packaging and Colors

Packaging

Size	Coverage (Textured, 2 coats)	Coverage (Smooth/White, 2 coats)
1 quart	~15 sq ft	~18 sq ft
1 gallon	~60 sq ft	~75 sq ft

Custom quantities available for commercial and fleet orders.

Available colors

Textured (16 colors): black, dark grey, light grey, brick red, bright red, military olive, white, brown, dark blue (vivid), orange, tan, light blue, sand, forest green, yellow, cream.

Smooth (15 colors): black, bright red, clear/colorless, cream, dark blue (vivid), dark grey, forest green, light blue, light grey, military olive, orange, sand, tan, white, yellow.

White grade: available as a smooth finish in both Outdoor/UV and standard formulations.

Custom color matching: available at 75-gallon minimum order with lead time. Colors are also hand-mixable by the user. UV-grade and non-UV-grade products look identical in the can; confirm the SKU before ordering for UV-exposed applications.

12. Limitations and Health & Safety

Limitations

• Durabak-18 is NOT suitable for: glass; marble or polished stone; any non-porous surface that cannot be scuffed to a dull profile.
• For UV-exposed applications, use Durabak-18 Outdoor / UV (this product), NOT Durabak Indoor. The indoor product uses an aromatic MDI curative and will amber and fade under sustained sun exposure.
• Do not apply over standing water, frost, condensation, or any substrate surface within 5 F of the dew point.
• Do not apply below 32 F or above 95 F ambient temperature.
• Substrate temperature must be 45 F to 90 F.
• Avoid recoating beyond the 24-hour maximum without abrading the first coat.
• Gasoline and acetone resistance is limited (Fair / Poor); for applications with prolonged fuel contact, verify suitability by field test.
• VOC: 250 g/L (2.08 lb/gal). This product meets the Federal EPA AIM 450 g/L limit and the CARB/OTC statewide 250 g/L Industrial Maintenance limit. Sold in California. CARB SCM-compliant as an Industrial Maintenance coating at <=250 g/L VOC. NOT available in the SCAQMD (greater Los Angeles) district or other air districts that enforce a 100 g/L Industrial Maintenance limit.

Personal protective equipment (PPE)

• Eyes: splash goggles or safety glasses with side shields.
• Skin: chemical-resistant gloves (nitrile or neoprene). Cover exposed skin.
• Respiratory: in confined or poorly ventilated spaces, use an organic-vapor respirator (OV/P100). For airless spray, a supplied-air or NIOSH-approved OV/P100 half-face respirator is required. IPDI is a respiratory sensitizer at elevated vapor concentrations; do not rely on odor as a warning -- provide adequate ventilation.
• Ventilation: apply in well-ventilated areas. Force-ventilate enclosed spaces (confined hold, cab, enclosed trailer). No open flame or spark sources.

VOC statement

VOC: 250 g/L (2.08 lb/gal) per ASTM D3960. Meets Federal EPA AIM Rule for Industrial Maintenance coatings (limit 450 g/L) and CARB/OTC 250 g/L. Sold in California. CARB SCM-compliant as an Industrial Maintenance coating at <=250 g/L VOC. NOT available in the SCAQMD (greater Los Angeles) district or other air districts that enforce a 100 g/L Industrial Maintenance limit.

California Proposition 65 warning

WARNING: This product can expose you to ethylbenzene, which is known to the State of California to cause cancer. For more information go to www.P65Warnings.ca.gov.

Flammability

Flash point 27 C (80.6 F), ASTM D56. GHS Flammable Liquid Category 3. Keep away from heat, sparks, welding, and open flame. Ground metal containers during transfer to prevent static discharge. Do not smoke near open containers.

First aid (summary)

For detailed first-aid, exposure, and emergency response information, consult the paired Safety Data Sheet.

Emergency telephone: 1-800-222-1222 (Poison Help - US national poison control hotline)

13. Disclaimer / Warranty

The information in this Technical Data Sheet is based on tests and data believed to be accurate as of the revision date. Durabak provides this data as a guide and makes no warranty, expressed or implied, regarding the fitness of the product for any particular purpose. Performance depends on surface preparation, application conditions, film thickness, and end-use environment, all of which are outside Durabak's control.

It is the user's responsibility to determine suitability for the intended application, to test the product on a small inconspicuous area before full application, and to comply with all applicable local, state, and federal regulations, including VOC limits, flammable-liquid handling requirements, and waste-disposal rules.

Durabak reserves the right to modify formulations, specifications, or these instructions without prior notice. Always use the most current Technical Data Sheet, available at durabakcompany.com.

This document is not a Safety Data Sheet. For complete hazard, exposure, and emergency information, refer to the paired SDS.

Revision date: 2026-06-18

Version: 1.0