Macropoxy L574

Technical Information

Macropoxy L574 (formerly known as metaguard L574) is a two-component, epoxy temporary protective primer.

Where To Use

Temporary protective 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.

Advantages

• Chemical resistant
• Water resistance properties

Application

Airless Spray
Nozzle Size : 0.38mm (15 thou)
Fan Angle : 80°
Operating Pressure : 155kg/cm² (2200 psi)
The airless spray details given above are intended as a guide only. Details such as fluid hose length and diameter, paint temperature and job 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.

Conventional Spray
Nozzle Size : 1.27mm (50 thou)
Atomising Pressure : 3.5kg/cm² (50 psi)
Fluid Pressure : 1.0kg/cm² (15 psi)
The details of atomizing pressure, fluid 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 fluid pressure depends on the length of line and direction of feed i.e. horizontal or vertical.

Brush
The material is suitable for brush application to small areas and for touch up purposes.

Roller
The material is suitable for roller application.

Preparation and Build-Up:
Metagard L574 is not intended to replace a coat of primer in the main paint specification, it is designed to provide temporary protection, until the specified paint scheme can be applied. However in practice, the use of Macropoxy L574 does make a substantial contribution to the performance of the complete paint specification in terms of ultimate durability and resistance to corrosion. The applied dry film thickness of prefabrication primers is normally below 30 microns. At this level of dry film thickness, factors such as blast profile, unevenness of application and severity of exposure conditions may signifi cantly affect the performance.

Epoxy paints should preferably be applied at temperatures in excess of 10ºC. 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 signifi cantly 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 Sherwin-Williams.