Sherwin Williams Macropoxy 646 Epoxy Primer Finish

Part A and B: UN1263 (Class: 3, Pk Grp: III)
A versatile high performance polyamide cured epoxy designed to fulfil the needs of both new construction and maintenance painting to steel, aluminium or galvanised steel.
Available in 5 and 20 Litres
From £189.68 £158.07
In stock
Only %1 left
Product Description

Sherwin Williams Macropoxy 646 Epoxy Primer Finish is a versatile high performance polyamide cured epoxy designed to fulfil the needs of both new construction and maintenance painting to steel, aluminium or galvanised steel.

Best Uses

Sherwin Williams Macropoxy 646 is best used as a primer finish for marine applications, pulp and paper mills, refineries, power plants, chemical plants, offshore platforms, tank exteriors, nuclear power plants, and water treatment plants. White colour is acceptable for immersion use for salt water and fresh water. Suitable for application to concrete floors.

Not acceptable for potable water. Tinting is not recommended for immersion service.


Prepare steel substrate to SSPC-SP10/NACE 2/Sa2½. Surface must be clean, dry, and in sound condition. Remove all oil, dust, grease, dirt, loose rust, and other foreign material to ensure adequate adhesion. Stripe coat all crevices, welds, and sharp angles to prevent early failure in these areas.

When using spray application, use a 50% overlap with each pass of the gun to avoid holidays, bare areas, and pinholes. If necessary, cross spray at a right angle. Spreading rates are calculated on volume solids and do not include an application loss factor due to surface profile, roughness or porosity of the surface, skill and technique of the applicator, method of application, various surface irregularities, material lost during mixing, spillage, over thinning, climatic conditions, and excessive film build.

Excessive thinning of material can affect film build, appearance, and adhesion. Do not mix previously mixed material with new. Do not apply the material beyond recommended pot life.

Technical Details


  • Norsok M-501 System 1 (Pre Qualified)
  • Norsok M-501 System 2B
  • Norsok M-501 System 4 (Pre Qualified)
  • Norsok M-501 System 5B (Pre Qualified)
  • Norsok M-501 System 6A
  • Norsok M-501 System 6B
  • Norsok M-501 System 7B (Pre Qualified)

Technical Info

Components: Two Pack
Type: Epoxy Primer Finish
Finish: Semi-Gloss
Stock Colours: White
Tintable: Yes. Please note, bespoke tints are non refundable / exchangeable
VOC Content: Unthinned:     <250 g/ltr
Thinned 10%: <300 g/ltr
Volume Solids: 72% ± 2%,
Suitable Substrates: Steel
Application Method: Brush, Roller, Airless Spray, Conventional Spray, or Plural Component Spray
Theoretical Coverage: Min: 5.76 m2/ltr, Max: 2.88 m2/ltr
Wet Film Thickness (WFT): Min: 175 Microns, Max: 347 microns
Dry Film Thickness (DFT): Min: 125 microns, Max: 250 microns
Induction Time: 30 minutes at 25°C
Pot Life: 4 hours at 25°C
Touch Dry: 2 hours at 25°C
Overcoatable: Min: 8 hours at 25°C, Max: 1 Year at 25°C
To Cure - Service: 7 days at 25°C
To Cure - Immersion: 7 days at 25°C
Cleaner / Thinner: C50
Shelf Life: 36 months from date of production unopened or 'use by' date where specified
Packaging: Available in 5 and 20 Litres

The manufacturers data sheets are available for download from this website. It is your responsibility to read and understand all aspects of the data sheets before you place an order and prior to application. Please pay special attention to the preparation, mixing and application temperatures of the product, cleaning of substrate and environmental factors such as temperature, rain etc. Quoted coverage rates are based on the manufacturers theoretical rates and may vary depending upon substrates absorption, texture and application. We always recommend a test is carried out to ensure suitability.

Customer further agrees that Promain have no liability for any errors or omissions contained within the Product Data Sheets and are not liable for failure due to misapplication or inadequate substrate cleaning and preparation. For more information please refer to our Terms & Conditions.

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