It is a well know fact that the Foundry Coatings are widely used to improve the surface casting finish and to achieve the best cosmetic look of the castings. But at the same time we all know that the best of the Foundry coating can never achieve this on a bad core or moulds. A conventional foundry using Sodium silicate CO2 gassed binder system uses mostly solvent based refractory coatings. In view of improving productivity, castings quality, to reduce rejection %, to have cleaner environment in the foundry, all modern foundries are shifting to modern resin systems such as phenolic ester cured, cold box resins, shell sand (Hot-Box), Furan Resin, Alpha set etc. Most of these sand resin systems whether for moulds or cores utilizes water based coatings to avoid casting defects such as metal penetration, sand erosion, veining etc.

Challenges before a Foundryman

• Complete de-hydration of coating
• Drying Oven parameters working efficiently

Above process is critical as wet coatings results into serious casting defects

• Scabbing
• Metal penetration
• Blowholes
• Surface Porosity

Foundryman needs visual confirmation of complete drying of coating

• To eliminate all moisture related defects
• To identify poor sand compaction in a core or mould [as these areas will absorb more moisture from coating and will take longer time to dry]
• To optimize on cost of drying Avoid over heating by oven/torch
• Avoid over dilution of coating as color of coating will fade
• Coating will take more time to change color due to higher moisture content
• Easy to apply multiple coats as Pink color coating will be applied on dried yellow coating