Macropoxy 400 (formerly known as Sherwin-Williams Macropoxy C400V3 and as Epigrip C400V3) is suitable for the protection of steelwork in a range of exposure environments from C1 to C5 as defined in BS EN ISO12944-2:2017, including buildings, car parks, petrochemical plants, breweries and power stations. Not for immersion service. Often specified for use as a primer for structural steel on blast cleaned steel for internal and external environments, it may also be used as a high build intermediate coat as well as the final coat where a low sheen industrial and functional finish is required.

All Epoxy products will lose gloss and colour when exposed in an external environment and so where good colour and gloss retention is required in an external environment, or a full decorative finish is required in an internal environment, a topcoat designed specifically for this role should be chosen. A selection of available topcoats is listed below in Recommended Topcoats.

Macropoxy 400 may be applied between 75 and 275 microns DFT in one coat depending on specification requirement. As many projects will differ in terms of client requirements and exposure environments, detailed project specifications are available from Sherwin-Williams separately.

Recommended Primers/Topcoats

Indefinitely overcoatable with epoxy systems provided the surfaces to be coated have been suitably cleaned. Where a high degree of gloss and colour retention is required overcoat with Acrolon C137V2, Acrolon C237, Acrolon 1850 and Acrolon 7300. Refer to the Product Data Sheet for details on surface preparation, drying times, etc.

Recommended thinner: No 2 (for thinning), No 9 or No 13 (for cleaning) 

Endorsements

• BS 476-7:1997 - Surface Spread of Flame
• BS EN 45545 Appendix D - Smoke Emissions - For details of substrate/scheme, consult our technical team.

Surface Preparation

Blast clean to Sa2½ BS EN ISO 8501-1:2007. Average surface profi le in the range 50-75 microns. Ensure surfaces to be coated are clean, dry and free from all surface contamination. Welds and repairs to previously blast cleaned substrate may be prepared to a minimum standard of St3 BS EN ISO 8501-1:2007 at the time of coating.

Application to such surfaces should be by brush or roller where the mechanical action will aid adhesion.

Application Equipment

Suitable for applying by brush and roller. Application of more than one coat may be necessary to give equivalent dry film thickness to a single spray applied coat.

The airless spray details given above are intended as a guide only. Details such as fluid hose length and diameter, paint temperature and substrate shape and size all have an effect on the spray tip and operating pressure chosen. However, the operating pressure should be the lowest possible consistent with satisfactory atomisation. As conditions will vary from job to job, it is the applicators’ responsibility to ensure that the equipment in use has been set up to give the best results. If in doubt Sherwin-Williams should be consulted. For MIO shades, use the 125-300μm recommendations.

Conventional Spray

• Nozzle Size: 1.27mm (50 thou)
• Atomising Pressure: 2.8kg/cm² (40 psi)
• Fluid Pressure: 0.4kg/cm² (6 psi)

The details of atomising pressure, fl uid pressure and nozzle size are given as a guide. It may be found that slight variations of pressure will provide optimum atomisation in some circumstances according to the set up in use. Atomising air pressure depends on the air cap in use and the fl uid pressure depends on the length of line and direction of feed i.e. horizontal or vertical.

For application by conventional spray, it may be necessary to thin the paint by the addition of up to 10% Cleanser/Thinner No. 2. Where thinning has been carried out the wet film thickness must be adjusted accordingly.

Application Conditions & Overcoating

This material should preferably be applied at temperatures in excess of 10ºC. Relative humidity should not exceed 90% and in these conditions good ventilation is essential. Substrate temperature shall be at least 3ºC above the dew point and always above 0°C.

At application temperatures below 10°C, drying and curing times will be significantly extended, and spraying characteristics may be impaired.

Application at ambient air temperatures below 5°C is not recommended.

In order to achieve optimum water and chemical resistance, temperature needs to be maintained above 10ºC during curing. If it is desired to overcoat outside the times stated on the data sheet, please seek advice of our technical team.

Additional Notes

Drying times, curing times and pot life should be considered as a guide only. The curing reaction of epoxies commences immediately the two components are mixed, and since the reaction is dependent on temperature, the curing time and pot life will be approximately halved by a 10°C increase in temperature and doubled by a 10°C decrease in temperature. Refer to the Product Data Sheet for details on colour stability and tropical use.

Typical Thickness and Coverage

Dry film thickness

75 microns

Wet film thickness

107 microns

Theoretical coverage

9.33m² /ltr*

*This figure makes no allowance for surface profile, uneven application, overspray or losses in containers and equipment. Film thickness will vary depending on actual use and specification.

Practical Application Rates

Microns per coat

Maximum sag tolerance typically 571μ wet (400μm dry) by airless spray and 179μm wet (125μm dry) by brush.

Average Drying Times

These figures are given as a guide only. Factors such as air movement and humidity must also be considered.