Background Prepare background Re-point and dub out as necessary with compatible mortar. Stipple Coat Cast or sprayed on only Must be used on poor suction, dense / smooth surfaces. Leave as Cast Cure 2 - 4 days First Coat Cast, spray or lay on. Well-keyed background. Control suction. Leave Keyed Cure 4 - 7 days Second Coat Cast, spray or lay on. Control suction. Straightening coat. Leave keyed. Cure 7 - 10 days. Finishing coat in 2 coats work. Finish Cast, spray or lay on. Control suction Finish as required. Cure min 3 - 10 days Cob / Earth Mix 1A - Sand SG3-5mm Mix 1B - Sand SG10-15mm Mix 1C - Sand SG5-10mm Mix 1C - Sand SF / FS3-5mm Wooden Lath   Mix 2B/3B - Sand SC12-15mm (8-10 cover) Mix 2C - Sand SC8-10mm Mix 1C - Sand SF3-5mmMix 2C - Sand SM5-8mm Metal Lath   Mix 3B - Sand SC10-15mm (8-10 cover) Mix 2B - Sand SM10-20mm Mix 1C - Sand SF3-5mmMix 2C - Sand SM5-8mm Soft Brick / StonePorous Blocks   Mix 1B - Sand SC10-15mmMix 2B - Sand SC10-15mm Mix 1B/C - Sand SC/SM10-12mmMix 2B/C - Sand SC/SM10-12mm Mix 1C - Sand SF3-5mmMix 2C - Sand SM5-8mm Medium Brick / Stone / Blocks Mix 2A/3B - Sand SG*3-5mm Mix 2B/3C - Sand SC10-20mmMix 2B/3B - Sand SG**10-15mm Mix 2C/3D Sand SC/SM8-12mmMix 2C/3C Sand SG**6-10mm Mix 1C - Sand SF3-5mmMix 2C - Sand SM5-8mm Dense Brick / Stone/ Blocks/ Concrete Mix 2A/3A -Sand SG3-5mm Mix 2B/3C - Sand SC10-20mmMix 2B/3B - Sand SG**10-15mm Mix 2C/3D Sand SC/SM8-12mmMix 2C/3C Sand SG** 6-10mm Mix 1C - Sand SF3-5mmMix 2C - Sand SM5-8mm NHL binder : sand mixes (by volume)   * Stipple coat optional, depending on background suction and conditions. ** For harling applications. Note: a wide variety of finishes can be achieved by adopting different binder and sand mixes to satisfy all requirements. Coat thickness and optional mix ratios are related to exposure and background conditions and are the responsibility of the designer.  Curing and protection must follow best working practice. Lime Mix A 1:1.5 Mix B 1:2 Mix C 1:2.5 Mix D 1:3 Mix E 1:4 NHL 2 1A 1B 1C 1D 1E NHL 3.5 2A 2B 2C 2D 2E NHL5 3A 3B 3C 3D    Sands Type Particle sizes SG Sharp gritty  5mm down to 0.075 SC Sharp coarse 3.35mm down to 0.075 SM Sharp medium 2.36mm down to 0.075 SF Sharp fine 1.18mm down to 0.075 FS Fine soft 0.8mm down to 0.075 This document is a guide only and is not intended to be a specification. Its purpose is to provide the reader with helpful information that may assist in determining the correct choice of materials, methods of application and the best working practice. The guidelines refer to our experience with St. Astier NHL binders and some recommendations might not be applicable to other products.