Applied Plastic Coatings, Inc.applicators of
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It has been said, that the cheapest coating on a properly prepared substrate will out perform the most expensive coating over a improperly prepared substrate. And for the most part this is true. This is why we have an extensive prep process to get you the best service life possible from your selected coating. For many coatings the ultimate preparation is a “Sandblast,” however selecting the right blast can be a challenge. Often when cost is a concern, a chemical process is selected instead (our minimum prep is a degrease, and an iron phosphate.) We also offer preparation that meats or exceeds Society for Protective Coatings' Surface Preparation guidelines seven (SSPC-SP7), six (SSPC-SP6), ten (SSPC-SP10), and five (SSPC-SP5), and guidance to help you select the right one for the job. Choice of appropriate media is critical. You need to select the appropriate size, shape ,and material. The cheapest material is silica sand, but silica when used as blast media releases small silicon dioxide particles, which can cause silicosis of the lung and other health problems. We have several media we routinely use. We use coal slag (a coal byproduct), garnet (rock), and Aluminum Oxide. These blast media have the advantage of being environmentally friendly (no known concerns for the people who use it, the air, the water, the flora, or fauna) and these are both angular media. Using an angular media produces a jagged or angular profile, unlike glass bead which produces a cratered profile. The angular profile gives an anchor for the maximum mechanically bond for optimum adhesion. When we take this and combine it with the appropriate size of blast media we have a profile depth (form the highest peak, to the lowest valley) that is 20% of the recommended dry film thickness (DFT) of the coating. This is to insure that at least 80% of DFT over the tallest peak, to prevent rust bleed or permeation with a coating that is too thin, and provide a good bonding surface, without the concerns of drips, sags, and runs. All this while removing rust, mill-scale, surface contaminates, and minor grind marks, leaving a surface that is ready to coat. Two final concerns, are that the blast does not leave contaminates on the part, and flash rusting. Freshly blasted ferrous parts can form iron oxide very rapidly and must be kept dry. Steel blast media can leave iron fragments in nonferrous parts causing them to rust. Air compressors often put small but significant amounts of oil into the air, which can be transferred to the part during blasting. Contaminates in the blast media can be transferred to the part. To manage this we keep our blast media as clean as possible, we use air dryers to remove oil and water form our compressed air, and store blasted parts in a controlled environment until coating, or customer pickup. Other available Media include plastic chips for removing some coatings without affecting the substrate, glass bead which is commonly used for frosting stainless steel, and walnut shell. If this seems like to many choices, we can help you chose the right media for your application. |