This was straightforward enough until the industry demanded a new specification for a cleanliness grade that could cut costs by replacing White Metal in situations where near-white was good enough.
The two versions were not equal: Sa 2. ISO declined to shoe-horn the new specification into their system as Sa 1. Despite the differences, the grades of cleanliness are generally thought to be compatible. They reflect similar permissible levels of stains and tightly-adhered rust, mill scale and coatings, and can be summed up with a chart:. ISO is a visual reference and does not explicitly state percentages.
The specifications specifically mention stains, streaks and shadows, but they are practically the same: a difference in color but of no discernible thickness. Tightly adhered material refers to anything that cannot be peeled off with a dull putty knife. Surface preparations standards exist to maximize coating life and minimize costs.
White Metal is expensive to achieve, especially on maintenance jobs, and typically reserved for critical applications where the cost of failure is catastrophic. Near white is good enough for service in most severe environments. Commercial is less expensive and suitable for non-corrosive atmospheres and service environments. Brush Off will save the owner the most money in the short run, if he can get away with it.
When choosing a coating, the owner weighs the costs of blasting and painting against the risk of a premature coating failure. If the worst-case scenario is that he has to repaint in 5 years instead of 7, he might save money by cutting back from Commercial to Brush-Off.
Visible deposits of oil, grease and dirt must be spot cleaned prior to abrasive blast cleaning. The standards specify numerous methods for solvent cleaning. The most common method — and the least effective — is washing with soap, water and a rag.
A dirty rag will also smear grease and oil: care must be taken to wipe, fold, repeat, and replace often. For large surfaces, pressure washing with soapy water is recommended, although soap residue will inhibit coating adhesion and should be rinsed off. Brush Off is specified to remove loose rust, mill scale and coatings, and uniformly roughen up a surface in preparation for a new coat. Tightly-adherent materials are permitted to remain.
Brush Off is specified where the expected life of the coating is short, such as ship hull antifouling, or in mild atmospheres and non-corrosive service environments, such as the exterior of a tank, in a rural location. Industrial is specified for conditions when the existing coating is thin, well-adherent and compatible with new coating.
It is the most recent abrasive blasting standard, and not widely specified. ISO has no corresponding specification. Commercial Blast Cleaning specifies that all tightly-adhering matter must go. Commercial is specified when a high, but not perfect, degree of cleanliness is warranted. Near White is typically specified for high performance coatings over steel exposed to severe environmental conditions, such as chemical spills and fumes, high humidity, and proximity to salt water.
It is commonly specified for off-shore platforms, shipyards and other marine environments. White Metal is the highest grade of abrasive blast cleaning. No shadows, streaks or stains are permitted. When viewed without magnification, the surface shall be free of all visible oil, grease, dust, dirt, mill scale, rust, coating, oxides, corrosion products and other foreign matter.
White metal is specified for steel serving under high temperatures, high pressures, and corrosive environments, and in cases where the catastrophic consequences of coating failure justify the extra expense, such as nuclear reactors, turbines, chemical tank linings, submarines, etc. ISO is a pictorial standard containing reference photographs that illustrate what each blast specification looks like on a variety of rust grades and initial conditions.
It comes in a hardcover A5 format that can be directly compared to the surface. Judging percentages of stains is an imprecise art that often causes rulers to come out. Preparing a job standard is a best practice for avoiding disputes:.
Surface preparation standards provide a basis for a service level agreement between blasters, contractors, inspectors and project owners. Knowing the standards are important for any abrasive blaster, and is a necessity for certified blasters.
The specifications contain detailed methods and practices for preparing surfaces. They are frequently updated, so refer to them by name, date, edition number, and supplement when discussing project standards. Thank you for contacting Graco. We have received your message and will contact you shortly.
What you need to know to choose the right nozzle for your abrasive blasting application. Know the facts: there is no such thing as dustless or dust-free blasting in surface prep. A guide to calculating a bid that is designed to meet your target profit margin.
Cookie Agreement Welcome! TS EN ISO Preparation of steel substrates before the application of paints and related products - Surface roughness characteristics of sandblasted steel substrates - Part 1: For the evaluation of abrasive blasted surfaces. TS EN ISO Preparation of steel base materials before the application of paint and related products-Surface roughness characteristics of sandblasted steel base materials- Part 2: Grade the surface profiles of abrasive blasted steel.
TS EN ISO Preparation of steel base materials before applying paint-related products - Surface roughness characteristics of sandblasted steel base materials Section 3: Calibration and determination of surface profile of ISO surface profile compressors. TS EN ISO Preparation of steel base materials before application of paint and related products - Surface roughness characteristics of sandblasted steel base materials - Part 4: Calibration and determination of surface profile of Iso surface profile comparators.
Preparation of steel surfaces - Before application of paints and related materials - Test methods for non-metallic abrasives used in spray cleaning - Part Determination of particle size distribution. TS EN ISO Preparation of steel surfaces - Before the application of paints and related materials - Test methods for non-metallic abrasives used for spray cleaning - Part 6: Determination of water soluble impurities by conductivity measurement.
Preparation of steel surfaces - Before application of paints and related materials - Test methods for non-metallic abrasives used in spray cleaning - Part Moisture determination TS EN ISO TS EN ISO Preparation of steel surfaces - Before application of paints and related materials - Test methods for non-metallic abrasives used in spray cleaning - Part 7: Determination of water soluble chlorides. Preparation of steel surfaces - Before the application of paints and related materials - Test methods for non-metallic abrasives used in spray cleaning - Part Determination of apparent density.
Rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings.
Worldwide Standards We can source any standard from anywhere in the world. You may find similar items within these categories by selecting from the choices below:. Please download Chrome or Firefox or view our browser tips. This part of ISO is applicable also to steel substrates that show residues of firmly adhering paint and other foreign matter in addition to residual mill scale. You can help Wikipedia by expanding it. Preparation of steel substrates before application of paints and related products.
Learn more about the cookies we use and how to change your settings. The faster, easier way to work with standards. Take the smart route to manage medical fn compliance. Essentially, these methods are intended for hot-rolled steel, but blast-cleaning methods, in particular, could also be used on cold rolling steel of sufficient thickness to withstand any deformation caused by the impact of the or the effects of power tool cleaning. Find Similar Items This product falls into the following categories.
The various grades are defined by written descriptions together with photographs that are representative examples within the tolerance for each grade as described in words.
0コメント