4 Finishing Options for Cast Iron Trench Grating
Several finishing options are available for those who would like their cast iron trench grates to have an aesthetic appeal. This article discusses some of those finishing options that you can consider when you order cast iron grates.
Uncoated Surface Finish
Many fabricators offer cast iron grates that are raw (uncoated). People who prefer this surface finish argue that cast iron will rust and eventually develop a patina due to its exposure to the elements. Such people see it as pointless to finish the grates in any other way. While this option reduces the cost of acquiring the grating system, it leaves the grates at the mercy of the elements. In other words, the grates will rust based on the intensity of the corrosive conditions to which they are exposed. You may therefore have to replace those grates sooner than you had anticipated.
Epoxy Surface Finishes
Epoxy paint can be applied on the surface of the grates in order to provide a measure of protection against rust. The coating keeps moisture away from the cast iron. Epoxy coatings tend to be durable due to their rugged nature. However, the coatings eventually chip or wear. This creates an opportunity for localised rusting to occur.
Powder-Coated Surface Finishes
Another way to finish cast iron trench grates is by powder-coating them. This finish provides a stronger bond between the paint and the substrate in comparison to using liquid paint. However, frequent vehicular traffic eventually causes the powder-coat to chip. It is for this reason that this surface finish is mainly recommended for residential applications. You can improve the longevity of your powder-coated grates by applying an epoxy primer before the powder-coating process begins. In this way, the epoxy will protect the parts that have been exposed when the powder-coat chips.
Bituminous Surface Finishes
You can also protect the grating from rust by applying a coating of bitumen on their surface. This coating makes the grates to become waterproof for some years. You can have a new coating applied once you notice that the previous one has degraded. However, the underside of the grating will not lose its protection as quickly as the exposed upper part. Consequently, the grating will not rust as quickly as cast iron grating with an uncoated surface finish.
Weigh the strengths and weaknesses of each of the finishes above before you make a final selection. You could also consult an expert for additional guidance so that you avoid making a costly mistake