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Carbomastic 615 Surface Tolerant Epoxy Mastic by Carboline

Carbomastic 615 Surface Tolerant Epoxy Mastic

by Carboline
$293.59 - $1,365.48
$293.59
$293.59 - $1,365.48
$293.59

Carbomastic 615 is a high-performance, surface-tolerant epoxy phenalkamine mastic engineered by Carboline for superior corrosion protection in industrial, marine, and maintenance environments with minimal surface preparation.
This high-solids coating offers exceptional moisture tolerance on damp/wet substrates, low-temperature cure, rapid return to service, and enhanced film strength via inert flake reinforcement (micaceous iron oxide), delivering reliable barrier protection against corrosion in fresh/salt water immersion, atmospheric exposure, and harsh conditions—ideal for steel structures, tanks, vessels, piping, and equipment where ideal prep is challenging. 

Carbomastic 615 PDS >
Finish: Semi-gloss 
Theoretical Coverage: approx. 100-200 SF/Gal depending on DFT

VIEW THE ENTIRE LINE OF CARBOLINE COATINGS HERE>

Key Features:

  • Outstanding Surface & Moisture Tolerance: Applies reliably over damp/wet or marginally prepared surfaces (e.g., hand tool cleaned, power tool cleaned, or existing coatings), with excellent wetting and adhesion in challenging conditions.
  • Low-Temperature & Fast Cure: Cures down to 20°F (-7°C) with rapid cure response for quick return to service, ideal for fast-turnaround projects or cold-weather applications.
  • High Solids, Low VOC & Enhanced Barrier: High-build formulation with micaceous iron oxide flakes for improved film strength, corrosion barrier, and durability in immersion and atmospheric exposures.

Common Industry Applications:

  • Marine & Offshore: Hulls, decks, structures, pilings, and equipment in saltwater immersion or splash zones; excellent for maintenance in harsh marine settings with limited prep.
  • Industrial Maintenance & Refurbishment: Steel structures, tanks, vessels, piping, and equipment in refineries, plants, and facilities requiring surface-tolerant coatings over rusted or existing systems.
  • General & Heavy-Duty Protection: Atmospheric and immersion service on bridges, power plants, wastewater facilities, and other aggressive environments needing durable, fast-cure epoxies with minimal downtime.

Carbomastic 615 is a TWO-COMPONENT SYSTEM (PART A & PART B).

Product type: Surface Tolerant Epoxy Phenalkamine Mastic.
Finish: Carbomastic 615 has a semi-gloss finish. 
Applied via: Airless Spray, Conventional Spray, Brush, or Roller

Shipping & Delivery: Carboline orders typically ship within 1-2 business days following receipt of order. Most orders are received in less than a week. Expedited shipping NOT available on most orders. 

Looking for a surface-tolerant epoxy mastic?
Contact our customer support today to discuss your project: 
(800) 567-5358

Size: 1Gal
Color: Light Tan (0200)
Coverage Calculator

Recommended Coating Systems

Surface Tolerant Wet, damp, or lightly rusted steel — no dry-down required
Cold Weather Cures to 20°F — apply during winter shutdowns
Fast Return to Service Immersion-ready in 60 min at 75°F
High Solids / Low VOC 80% solids by volume — fewer coats, less waste
Marine Maintenance — Hull & Structural Steel
Surface prep: SSPC-SP10 / NACE No. 2 — 2.0–3.0 mil profile (immersion)
Primary Coat Carbomastic 615 5–10 mils DFT · wet surface OK
→
Topcoat (Optional) Carbothane 134 HG 2–3 mils DFT · color & UV stability
⏱ Immersion-ready after 60 min cure at 75°F. At colder temps, minimum immersion cure is longer — see cure schedule.
Wastewater / Treatment Plant Steel — Immersion Service
Surface prep: SSPC-SP10 / NACE No. 2 — 2.0–3.0 mil profile required for immersion
1st Coat Carbomastic 615 5–10 mils DFT
→
2nd Coat Carbomastic 615 5–10 mils DFT · allow min. recoat time
⚠ Allow minimum dry-to-topcoat time between coats (2 hrs at 75°F). If maximum recoat time is exceeded, abrade before recoating.
Industrial Atmospheric — Oil & Gas / Structural Steel
Surface prep: SSPC-SP6 / NACE No. 3 minimum — 2.0–3.0 mil profile for maximum protection
Primer / Single Coat Carbomastic 615 5–10 mils DFT · direct to metal
→
Finish Coat Carbothane 134 HG or 133 LH Color, UV & chemical resistance
💡 Dry surface job? If your steel is dry and conditions are standard, Carbomastic 15 may be a better fit — aluminum-pigmented, CUI rated to 300°F.

Frequently Purchased Together

Carboline Thinner No. 2
PDS-Specified Thinner
Carboline Thinner No. 2
Preferred thinner for CM615 per PDS. Thin up to 12% by volume. Also used for tool and equipment cleanup.
From $129.87
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Carbothane 134 HG Polyurethane Topcoat by Carboline
Finish Coat — High Gloss
Carbothane 134 HG
High-gloss aliphatic polyurethane. Color, UV resistance & long-term service life over CM615. ISO 20340-tested system.
Call for pricing
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Finish Coat — Satin / Low Sheen
Carbothane 133 LH
High-build satin aliphatic polyurethane. Low HAPs, indefinite recoatability. Use when a low-sheen finish is preferred over gloss.
Call for pricing
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Carbomastic 15 Epoxy Mastic by Carboline
Dry Surface Alternative
Carbomastic 15
Use when surface is dry. Aluminum-pigmented epoxy mastic. CUI rated to 300°F. Ideal for insulated pipe and dry steel.
Call for pricing
Shop Now

Product Specs — Carbomastic® 615

Carbomastic 615 — Phenalkamine Epoxy Mastic (MIO-Reinforced) by Carboline.
High performance, self-priming epoxy with outstanding moisture and surface tolerance during application. Reinforced with Micaceous Iron Oxide (MIO) for enhanced barrier protection. Cures down to 20°F (−7°C). Suitable for fresh water and salt water immersion after 60-minute cure at 75°F.

Property Value
Product TypePhenalkamine Epoxy (MIO-reinforced)
Mix Ratio4:1 by volume (Part A to Part B) — 1 gal kit: 0.8 gal A + 0.2 gal B — 5 gal kit: 4 gal A + 1 gal B
Pot Life1.5 hours at 75°F (24°C) — decreases at higher temps
FinishSemi-gloss
PrimerSelf-priming
Standard Colors0200 (Tan), 0700 (Grey)
Special Order Colors0500 (Red), C900 (Black)
Minimum Cure Temp20°F (−7°C) surface / ambient
DFT per Coat5–10 mils (127–254 microns)
Solids by Volume80% ± 2%
Dry Temp Resistance200°F (93°C) continuous — 250°F (121°C) non-continuous
Application MethodsAirless Spray, Conventional Spray, Brush, Roller
SubstratesSteel, damp/wet steel, concrete, non-ferrous metals, existing coatings (not over latex)
Shelf Life24 months (Parts A & B) at 75°F in original unopened containers
✔ Wet & damp surface tolerant  •  ✔ Cures to 20°F (−7°C)  •  ✔ Fresh & salt water immersion rated  •  ✔ Immersion-ready after 60 min cure @ 75°F

✏ Need a project quote? Request Online

📞 Questions? Call (800) 567-5358 — Mon–Fri 8AM–5PM EST

Carbomastic® 615 by Carboline

Carbomastic 615 phenalkamine epoxy mastic coating kit by Carboline
Carbomastic® 615 — MIO-Reinforced Phenalkamine Epoxy (Parts A & B)

Wet surface specialist. Applies directly to damp or wet steel — no surface drying required. Not for use into standing water or ponded conditions.

Cold weather capable. Cures down to 20°F — ideal for winter maintenance shutdowns where most epoxies cannot be applied.

Fast return to service. Immersion-ready after just 60 minutes cure at 75°F. Dry to handle in 2 hours at 75°F.

Dry surface alternative: For dry steel or CUI service to 300°F, see Carbomastic 15 instead.

Shipping Map — Carboline Delivery Timing

Carboline US regional warehouse shipping map showing typical 2, 3, and 4-day delivery transit zones 🔍 Click to enlarge
Typical transit times vary by destination zone. Click map to enlarge.

Shipping Time

Call (800) 567-5358 for pricing and logistics questions.

Carboline orders ship from regional warehouses nearest to your location, with full product stock maintained at each facility.

Most orders ship within 2–3 business days of order placement. Transit times shown on the map are typical but not guaranteed.

Carbomastic 615 — Coverage Rates by DFT

Typical DFT: 5–10 mils per coat. Solids content 80% ± 2% by volume. Coverage varies significantly with DFT — size your order from the table below, not by eye. Allow for loss in mixing and application.

DFT per Coat Theoretical Coverage Typical Use Case
1 mil (25 microns) 1,283 ft²/gal Reference only — below recommended DFT range
5 mils (125 microns) 257 ft²/gal General maintenance — dry or damp steel, atmospheric
7 mils (175 microns) 183 ft²/gal Marine maintenance — moderate exposure
10 mils (250 microns) 128 ft²/gal Heavy marine / wastewater / severe immersion

Theoretical coverage per Carboline PDS March 2023 (1049) — 80% solids by volume, 1,283 ft²/gal at 1 mil. Actual coverage varies with surface profile, application method, and operator technique. Allow for loss in mixing and application.
Source: Carboline Carbomastic 615 Product Data Sheet (March 2023)

Curing Schedule — Carbomastic 615

Based on 5–10 mil DFT per coat. Higher film thickness, insufficient ventilation, or cooler temperatures require longer cure times. Any surface haze from humidity must be water-washed before recoating.

Surface Temp. Dry to Topcoat (Min) Max Recoat Time Min Cure for Immersion
20°F (−7°C) 72 Hours 45 Days 7 Days
35°F (2°C) 2 Days 30 Days 5 Days
60°F (16°C) 8 Hours 15 Days 3 Hours
75°F (24°C) 2 Hours 7 Days 1 Hour
90°F (32°C) 90 Minutes 3 Days 1 Hour

If maximum recoat times are exceeded, abrade surface by sweep blasting or sanding before applying additional coats. Source: Carboline Carbomastic 615 PDS March 2023.

Good to Know Before You Buy

Carbomastic 615's wet-surface capability is genuinely useful — but there are specific limits. These are the things contractors get wrong most often.

⚠ Critical Clarification "Wet Surface" Does Not Mean Underwater Application CM615 can be applied to surfaces with surface moisture — but you cannot apply it into standing water or submerged conditions. Remove standing water and ponding before application. The steel can be wet to the touch; it cannot be sitting in water. For immersion service, follow SSPC-SP10 surface prep requirements.
ℹ Color & Appearance MIO Finish = Dark Gray to Greenish Appearance Standard colors are Grey (0700) and Tan (0200). Special order: Red (0500) and Black (C900). The MIO reinforcement gives grey shades a dark, slightly greenish cast. CM615 is not a finish coat. For a specific finish color and UV stability, topcoat with Carbothane 134 HG.
⚠ Mix Ratio — Critical 4:1 Ratio (A:B) — Not 2:1 Carbomastic 615 uses a 4:1 ratio by volume (Part A to Part B). This is different from some other Carboline mastics. Confirm the ratio from your kit labels and the current PDS before mixing. Do not mix partial kits — the ratio must be maintained exactly.
⚠ Cure Windows Phenalkamine = Longer Cure Times at Very Cold Temps While CM615 cures at temperatures down to 20°F, cold temperatures extend cure times significantly. At 20°F, dry-to-topcoat is 72 hours and minimum immersion cure is 7 days. Pot life is 1.5 hours at 75°F — plan your mix quantities accordingly and do not apply past pot life.
⚠ Coverage Estimate Wide Coverage Range — Size Your Order from the DFT Table Coverage ranges from 128 to 257 ft²/gal depending on DFT (theoretical, per PDS). That is a 2x swing — ordering by guesswork is a common and expensive mistake. Use the TDS DFT table or the Coverage Calculator on this page to size your order correctly.
⚠ Substrate Restriction NOT Over Latex Coatings Like most epoxy mastics, Carbomastic 615 must not be applied over latex (water-based) coatings. Adhesion failure will occur. Test or identify any existing coating before ordering.

Frequently Asked Questions — Carbomastic® 615

What is the coverage rate for Carbomastic 615?
Per the Carboline PDS (March 2023), theoretical coverage is 257 ft²/gal at 5 mils DFT and 128 ft²/gal at 10 mils DFT, based on 80% solids by volume. Allow for loss in mixing and application. Use the Coverage Calculator on this page and verify against the current PDS DFT table before ordering.
Can I apply Carbomastic 615 to a wet surface?
Yes — CM615 is specifically formulated for wet and damp steel surfaces. However, "wet surface" does not mean standing water or submerged conditions. The steel can have surface moisture; it cannot be sitting in or ponded with water during application. Remove all standing water before coating. For non-immersion applications over damp surfaces, brush and roller is the preferred method per the PDS.
How cold is too cold to apply Carbomastic 615?
Carbomastic 615 can cure down to 20°F (−7°C) surface and ambient temperature. This is significantly colder than standard epoxies. At 20°F, dry-to-topcoat minimum is 72 hours and minimum cure for immersion service is 7 days. Do not apply to substrates with ice or ice crystal formation — dehumidify or raise temperature to eliminate ice before coating.
What is the mix ratio for Carbomastic 615?
Carbomastic 615 uses a 4:1 mix ratio by volume (Part A to Part B). For a 1-gallon kit: 0.8 gal Part A to 0.2 gal Part B. For a 5-gallon kit: 4 gal Part A to 1 gal Part B. Mix each component separately, then combine and mix until homogeneous. Do not mix partial kits. Pot life is 1.5 hours at 75°F.
What surfaces can Carbomastic 615 NOT be applied to?
Carbomastic 615 must not be applied over latex (water-based) coatings — adhesion failure will occur. It must not be applied into standing water or ponded conditions. Do not apply to substrates with ice or ice crystal formation. Always verify existing coating type before application.
What color is Carbomastic 615?
Standard colors are Grey (0700) and Tan (0200). Special order colors are Red (0500) and Black (C900). The MIO reinforcement gives the grey shade a dark, slightly greenish appearance. CM615 is not a finish coat. For a specific finish color and UV stability, topcoat with Carbothane 134 HG.
Is Carbomastic 615 rated for immersion service?
Yes — CM615 is suitable for fresh water and salt water immersion after a minimum 60-minute cure at 75°F. For immersion service, surface prep must meet NACE No. 2 / SSPC-SP10 with a 2.0–3.0 mil surface profile. Confirm minimum immersion cure time for your job temperature using the curing schedule table on this page.
What is the difference between Carbomastic 15 and Carbomastic 615?
Key differences: CM15 is aluminum-pigmented, requires a dry surface, and is rated for CUI service to 300°F. CM615 is MIO-reinforced, tolerates wet and damp surfaces, cures to 20°F, and is immersion-ready after 60 minutes at 75°F. For dry steel with elevated temperature requirements, CM15 is the better choice. For wet, damp, or cold-weather maintenance, CM615 is the right product.

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