Sherwin-Williams Macropoxy L574 (formerly known as Metagard L574) is a two-pack temporary protective primer for steel surfaces prepared by abrasive blast cleaning.

• Suitable for use in conjunction with cathodically protected steel. Suitable for welding and fabrication and for overcoating with most paints in common use except high content metallic zinc products (see note on fabrication overleaf).
• As a sealer for aluminium and zinc metal spray.
• As a primer for use over stainless steel and non-ferrous metallic substrates. 

Endorsements 

• Network Rail item No. 7.1.2 

Recommended 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 within 7 days at a minimum dft of 50 microns or in the case of Acrolon C750V2 overcoat within 4 days. These overcoating times refer to achievement of optimum adhesion at 23°C and will vary with temperature.

For overcoating with alkyd systems, consult Technical Team for advice. 

Application Conditions & Overcoating

Epoxy paints should preferably be applied at temperatures in excess of 10°C. In conditions of high relative humidity, i.e. 80-85% good ventilation conditions are essential. Substrate temperature shall be at least 3°C 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 10°C during curing. If it is desired to overcoat outside the times stated on the data sheet, please seek advice of Rawlins Paints. 

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.

Fabrication: While Macropoxy L574 Primer is classed and approved as a welding primer, under certain types of welding operations e.g. high speed twin-fillet welding, fabricators are advised to satisfy themselves that the product is suitable for their particular welding process.

Epoxy Coatings - Tropical Use: Epoxy paints at the time of mixing should not exceed a temperature of 35oC. Use of these products outside of the pot life may result in inferior adhesion properties even if the materials appear fit for application.

Thinning the mixed product will not alleviate this problem.

It is not advisable to apply epoxy coatings when the air and substrate temperatures exceed 45oC. These conditions can introduce paint film formation defects, such as dry spray. bubbling and pinholing etc.

Numerical values quoted for physical data may vary slightly from batch to batch.