Sherwin-Williams Heat-Flex M505 is an air drying silicone resin based heat resistant matt finish coating. It is used for application on to steel surfaces previously coated with Dox-Anode D5V2 or zinc or aluminium metal spray, where heat resistance is required. 

• Please note: Also available in White 5L and Aluminium 20L subject to a a minimum order quantity of 200L and an extended lead time of 14 working days. Please see Sherwin-Williams Heat-Flex M505 - Special Order

Recommended Primers/Topcoats

• Zinc Clad II EU (up to 400°C)

Topcoat not normally required, but indefinitely overcoatable with itself. 

Surface Preparation

Ensure surfaces to be coated are clean, dry and free from all visible traces of surface contamination. Any contamination of metal spray will prevent the M505 film penetrating and sealing, leaving it sitting on top and prone to blowing off.

M505 is not designed to provide anticorrosive protection, but it is possible to apply the product in 2 coats directly onto blast cleaned steel to Sa21⁄2 BS EN ISO 8501-1:2007 ( average surface profile in the range of 50-75 microns ) provided it is put into service quickly and kept at elevated temperatures. Steelwork coated with M505 should not be exposed to moisture prior to putting into service ( see additional notes below). 

Additional Notes

Over-application

Over-application of M505 must be avoided. If the recommended film thickness is exceeded, adhesion may be reduced especially when exposed to high temperatures. Adhesion of M505 may be adversely affected if the applied film is subjected to a very rapid rise in temperature when first brought into high temperature service, due to thermal shock effects - post curing of the applied film is therefore recommended, see note below.

Post-Curing

If M505 is to be exposed to ambient weathering or moisture before service, it is required that the coating is post-cured by gradually elevating the temperature to a minimum of 205°C and maintaining this temperature for 2 hours.

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

USE AS A SEALER FOR THERMALLY SPRAYED METAL COATINGS:

M505 is suitable for use as a sealer for thermally sprayed aluminium (TSA) or zinc (TSZ). Application spreading rate will be dependant upon the porosity of the substrate. Recommendation as stated in NORSOK M501 Rev 6 should be followed:- “The sealer shall fill the metal pores. It should be applied until absorption is complete. There shall not be a measurable overlay of sealer on the metallic coating after application”.

Post curing of M505 applied as a sealer for TSA or TSZ is not required.