Surface cleanliness and profile are the cornerstones of proper surface preparation, but those standards are not always met. Frequently, metal fabrication projects suffer from bad surface prep. When steel is cut with flame or plasma, the edges that have been cut become harder than the middle part of the steel. This creates challenges for those trying to follow coatings application best practices.
Flame and plasma cut steel is notoriously hard to profile with abrasive blasting. When regular abrasives like garnet or steel grit collide with hardened steel, they bounce off without imparting a profile. This indicates that the steel’s cut edge is harder than the garnet, steel grit, or whatever common abrasive is being used. On metal fabrication projects like bridge construction and repair, these hardened edges are often manually ground because many believe this is the only option. Metal fabrication industry professionals have discovered that Sponge-Jet’s Silver Media is capable of easily and consistently profiling plasma cut or other hardened steel.
Sponge Media is unique in the abrasive blasting world. Very hard ceramic abrasives combine with sponge to form each composite particle. The sponge like component of the composite abrasive allows for unique transfer of energy of each abrasive into the hardened steel. The result is a properly profiled surface that is similar to the rest of the steel. This consistent profile leads to better coatings application and ultimately longer coatings life. Additionally, this process, often referred to as “Dustless Blasting” can easily be implemented outside of a traditional blast room so that large fabrications need not be transported back to the blasting room after cutting.
Ultimately, coatings fail at the weakest point. Blasting hardened edges with Sponge-Jet is one way to ensure consistent surface cleanliness and profile suitable for any steel fabrication or repair project.
To learn more about Surface Preparation, click below to get our Guide to the 5 Keys to the Best Surface Prep.