Your Plans call for Blasting and Priming – what you need to know?
Why Blast and Prime?
Do your construction drawings call for blast and prime or galvanized material? There is a significant difference between the Blast and Prime (B&P) process and Hot-dipped galvanizing. Blasting metal for preparation of a primer application is necessary to ensure that the metal primer adheres to the surfaces successfully preventing chipping and erosion of the paint. When we don’t follow this process, the paint will wear faster and so more maintenance will be required.
But how is it done?
It is necessary to remove the mill scale and residue to ensure that once the primer is applied, it will last longer without chipping or cracking. Just as when you paint a room in your home, preparing the surface brings longevity to your finished product. While galvanizing is similar in some respects, these two processes are not created equal.
In a controlled environment, a blasting hose with nozzle is used to remove the substrate surfaces of mill scale, rust and other visible contaminants. Once completed it is then primed to a color, usually called out by the engineer, and allowed time to dry. For optimal adherence and proper application this should not be done when it is raining outside. The most common colors used are red, safety yellow, blue and black. If your plans do not call this out, check with the structural engineer because often they will have designated a specific product and color for the project specifications.
FDOT Projects and other applications
Here in Florida, FDOT requires not just a blast and prime but also the process of galvanizing which will be addressed in our next blog. FDOT plans typically call for pipe bollards to be blasted and primed safety yellow AND galvanized. While doing one is often considered the same as doing the other and produce the overall same protection, galvanized metal will last far longer than painted. If you the structural plans call for both processes, it is important to know there is a specific process whereby galvanized material can then be painted to meet your project specifications.
Architects and structural engineers will call for priming of the structural materials before installation to prevent atmospheric conditions from corroding the material. The goal is to protect the structure internally and externally for moisture intrusion. We all know the atmospheric conditions here in Florida is corrosive to steel and therefore this process is essential to the integrity of the structure over time.
Blasted and primed materials you might see in your everyday world are things like parking lot bollards. You seem them in front of handicapped designated parking, emergency access points, at bus stations and in front of businesses.
At Spirit Metals we are Contact Uscommitted to providing the ultimate customer experience along with value pricing. Whether you are looking for standard structural steel or something special like Stainless Steel, corrugated metal, Corten or HD Bar grating, look no further! We can provide whatever you need for your next project, just click here to contact us today and one of our dedicated team members will call you back immediately to discuss what you need and answer any questions you may have.