Carboline Carbomastic 20


Carboline Carbomastic 20 is a two-component, corrosion resistant epoxy mastic for steel, offering very good protection against fresh and salt water.

Not recommended for immersion service in aromates, ketones or strong oxidizing acids.

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£271.80 Tax incl.


Carboline Carbomastic 20 is a two-component, corrosion resistant epoxy mastic for steel, offering very good protection against fresh and salt water.

Not recommended for immersion service in aromates, ketones or strong oxidizing acids. Topcoats: May be topcoated with most two-pack topcoats.

Note: Epoxies lose gloss, discolour, and eventually chalk in sunlight exposure.

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Features and Benefits

  • Surface tolerant
  • Fast curing at low temperatures
  • High solids give good coverage and reduced solvent emission
  • Semi-gloss finish

Product Specification

Technical Data
Carboline Carbomastic 20
Volume Solids: 85 ± 2%
Theoretical Coverage Rate: 6,5 m²/l at 130 µm
Allow for loss in mixing and application
Dry Film Thickness: 100 - 300 microns (3.94 - 11.81 mils) per coat
Normally 130 µm
Wet Film Thickness: 120 – 350 µm per coat, normally 155 µm
Dry Temperature Resistance: Continuous: 120°C (248°F)
Non-Continuous: 150°C (302°F)
Shelf Life: 36 months at 24°C
Storage Temperature and Humidity: 5° - 45°C
0 - 95% relative humidity

Drying Times

Curing Schedule
Surface Temp. Dry to Recoat Final Cure
5°C (41°F) 24 Hours 30 Days
15°C (59°F) 10 Hours 20 Days
20°C (68°F) 8 Hours 10 Days
25°C (77°F) 5 Hours 10 Days

  • These times are based on 130 µm DFT. Higher film thickness, insufficient ventilation or cooler temperatures will require longer cure times and could result in solvent entrapment and premature failure

Surface Preparation


  • Surfaces must be clean and dry
  • Employ adequate methods to remove dirt, dust, oil and all other contaminants that could interfere with adhesion of the coating


  • For immersion service, blast clean to Sa 2½ (ISO 8501-1), for other service St 2-3 (ISO 8501-1) may be sufficient
  • Alternatively, ultra-high pressure water jetting to Nace No. 7 min. C Vis WJ-2. Max flash rust; C Vis WJ-2M

Application Methods

Product Information
Mixing: Power mix separately, then combine and power mix
Thinning: May be thinned up to 15% with Thinner 2
Use of thinners other than those supplied or recommended by Carboline may adversely affect product performance and void product warranty, whether expressed or implied
Ratio: 3:1 Ratio (A to B) by volume
Pot Life: 3 Hours at 20°C and less at higher temperatures
Airless Spray: Pump Ratio: 30:1 min
Volume Output: 3.0 gpm min
Material Hose: 3/8” I.D. min
Tip Size: 017”-.023”
Output PSI: 2400
Filter Size: 60 mesh
Brush and Roller: Recommended for small areas only

Application Conditions

Product Conditions
Condition Material Surface Ambient Humidity
Minimum 5°C (41°F) 5°C (41°F) 5°C (41°F) 0%
Maximum 35°C (95°F) 50°C (122°F) 40°C (104°F) 85%

  • Industry standards are for substrate temperatures to be 3°C above the dew point
  • Condensation due to substrate temperatures below the dew point can cause flash rusting on prepared steel
  • Special application techniques may be required above or below normal application conditions

Health and Safety

Clean Up

  • Use Thinner 2 or Acetone
  • In case of spillage, absorb and dispose of in accordance with local applicable regulations


  • Read and follow all caution statements on this product data sheet and on the safety data sheet for this product
  • Employ normal workmanlike safety precautions
  • Hypersensitive persons should wear protective clothing, gloves and use protective cream on face, hands, and all exposed areas


  • When used as a tank lining or in enclosed areas, thorough air circulation must be used during and after application until the coating is cured
  • The ventilation system should be capable of preventing the solvent vapor concentration from reaching the lower explosion limit for the solvents used


  • This product contains flammable solvents. Keep away from sparks and open flames
  • All electrical equipment and installations should be made and grounded in accordance with the applicable local regulations
  • In areas where explosion hazards exist, workmen should be required to use non-ferrous tools and wear conductive and non-sparking shoes
  • Refer to the product and safety data sheet in the attachments section above for further details

It is your responsibility to read the Product Data Sheets (available below) before you place an order and prior to application of the product. The content of this website is our best recommendation and is not advice. Coverage rates quoted are approximate, you agree that coverage depends on the condition of the substrate, surface absorption, texture and application method. We ALWAYS recommend a trial area is coated to ensure the product meets your requirements before use.

Product Details

Data sheet

For Use On
Application Method
Brush, Spray, Roller
Standard / Ready Mixed
Single, Two or Three Pack
Pack Size
Mixing Ratio
3:1 Ratio (A to B) by volume
Dry to Recoat (at 20°C)
8 Hours
Fully Cured (at 20°C)
10 Days
Pot Life (at 20°C)
3 Hours
6,5 m²/l at 130 µm
Recommended Thinner/Cleaner
Carboline Thinner 2
Max. Application Temperature
Material: 35°C (95°F) - Surface: 50°C (122°F) - Ambient: 40°C (104°F) - Humidity: 85%
Min. Application Temperature
Material: 5°C (41°F) - Surface: 5°C (41°F) - Ambient: 5°C (41°F) - Humidity: 0%
Solids by Volume
85 ± 2%
Shelf Life (from date of manufacture)
36 months at 24°C
Recommended Dry Film Thickness
100 - 300 microns (3.94 - 11.81 mils) per coat. Normally 130 µm
Recommended Wet Film Thickness
120 – 350 µm per coat, normally 155 µm
UN Number

Customer agrees that before placing an Order, Customer has read and understood the most up to date Product Data Sheet for the Product. Where we have access to the Product Data Sheet from the manufacturer, we will either provide a copy on request, or include a link to the Product Data Sheet available on the manufacturer’s website. Customer further agrees that we have no liability for any errors or omissions contained within the Product Data Sheets. For more information, please see our Terms & Conditions of Sale.

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