Measuring dry film coating thickness according to sspcpa 2kta. Applying too much wet coating will not only waste time and money, but there is also a possibility of the coating cracking during the curing process. It is important that a coating is applied to the correct thickness. Wet film coating thickness measurement is an early method of determining whether the dry film coating thickness will be correct. Modern technology has helped manufacturers to produce dry film thickness gauges that are smaller in size but packed with more features that make measurement easier, faster and more accurate. How to achieve desirable dft dry film thickness for water. Dry film thickness is probably the most critical measurement in the coatings industry.
When you measure the wet film thickenss you must do so immediately after you have applied the coating. How to measure dry film thickness using an elcometer 415. We are most familiar with wet density, which is commonly called weight per gallon in the united sates. The coating average thicknesses that i have are from a range that our facility has for min and max coating thickness. Dry film thickness measurement wood substrates resources. Liquid coating determining weightthickness aimcal fall. For more information or help to predict the thickness of paint that you are applying complete our getintouch form below or call us at 3122802300. Astm d62 2017 standard test method for nondestructive. What is the difference between wet paint density, specific gravity and dry film density. Under application will result in premature failure of the paint system. Easily convert and calculate the wet and dry film thickness and coverage of coatings applied to a substrate. Measurements of dry film coating thickness on steel archived. D1640 test methods for drying, curing, or film formation of. D48 practices for measurement of dry film thickness of protective coating systems by destructive, crosssectioning means.
The wet film thickness figure given on a specification relates to the thickness of the coating when it has just been applied and is still wet, as soon as the coating begins its drying process solvents and volatiles will be leaving the coating and its thickness will reduce and once cured its dry film thickness can be read. Wet film combs measure wet film thickness, and are available in a variety of materials. Usually the percentage of solids by volume in a coating will be known. Oct 23, 20 wet film thickness gage a wet film thickness gage is an inexpensive and easytouse tool that quickly measures coating thickness. It ensures that you are applying the correct amount of paint to achieve the performance properties of the coating. The units of measure for these gages is typically micrometers microns or mils. Usually, nominal dry film thicknesses are specified but sometimes minimum values are quoted. The performance of a coating system is based upon correct application of this system following the paint manufacturers specification sheet. The paper will show that even this most basic aspect of the. If you know the volume solids of the coating, you can use a wet film thickness gauge to predict the dry film thickness. Large enough to meet your needs small enough to offer superior service. Sspcpa 2 measurement of dry paint thickness with magnetic gauges procedures to measure dry film thickness of nonmagnetic coatings over magnetic substrates type 1 magnetic pulloff type 2 fixed probe calibration type 1 verify accuracy on nist plates measure a several points on bare, prepared substrate. Applying coatings outside recommended coating thickness.
It was also shown that there is no benefit in time savings and sample handling in making volume solids determinations by the film thickness technique,when the manufacturers recommended conditioning schedule is used to cure the paint film. Height measurement measuring before and after with a micrometer. The elcometer 415 industrial paint thickness gauge delivers simple, fast and accurate coating thickness measurements on a wide range of. The wet density d is the mass m of the sample liquid divided by its volume v, or as an equation d mv. Computing film thickness and coverage this months column, which originally appeared in the july 1991 issue of jpcl, has been revised and updated by pce european editor brian goldie. The thickness of paint after it has dried can be measured using a dry film thickness gauge 10.
Intumescent paints efficient way of protection of steel. If a specification called for a dry film thickness of 2 mils, the theoretical coverage would then be 722 square feet divided by 2 mils, or 361 square feet per gallon. Wet film measurement is done by devices based upon the shape of the surface area, and the expected range of thickness. Modern electronic gauges have provided the ability to take hundreds of readings. Measuring on drywall required other measuring techniques including. Astm d5895 standard test methods for evaluating drying. Generally speaking, higher quality paints have higher volume solids than do economy paints, and so they dry to a thicker film for a given spread rate. Exceeding the specified film thickness can be equally dangerous. Simply put, dry film density is just the mass of the dry paint film divided by the volume of the dry paint film.
An adequate film thickness is mandatory for the success of any coating system. I dont think that i can just leave out the units in mm of the average thickness. Often both a dry and wet film thickness is specified. Relationship between wet film thickness and dry film thickness. Results are calculated by inputing foil sample dimensions and measured foil sample weight, with and without dry coating film. When adding thinner to a coating, consider the amount being added and its effect on spreading rate. The problem with meeting dry film thickness specifications. Nov 10, 2017 instruments that measure the dry film thickness of the applied coating reach part way down into the roughened metal surface to operate properly illustrated by the red line. The dry film thickness gauge has been an essential tool in making sure that coating thicknesses are within specifications. Dry film thickness of intumescent products for structural steel is determined by the following factors. Intumescent coatings applied to a steel ibeam, or wprofile left, create a thick char and swell to approximately 50 times their dry film thickness dft in a fire right, thereby providing protective insulation that reduces the rate of heat transfer to the steel. Choose from a variety of coating thickness gauge, mil gage or paint meter products. Coating thicknessdry film coating inspection equipment. Substitution placing a steel coupon alongside the wood part and coating it at the same time.
In particular, pspc introduced the concept of a minimum dry film thickness dft based on the 90. Standard gauges, used to measure dry paint film coating. Predict the thickness of paint carbit paint company. This paper focuses on the problems meeting specified dry film thickness dft, which is considered to be the best understood and the most objective element of coating application. The relationship between dry film thickness and wet film. Dry film thickness dft is perhaps the single most important parameter in protective coatings activities, specified and measured in virtually every coating project. Please check the instructions for use of the coating or the material safety data sheet msds. Wet and dry film thickness formulae ultrimax store.
If you have entered a sign in name then the password reset email will be sent to the email address linked to your sign in name. The highest number tooth with paint indicates the thickness of the. Drywall is typically painted with 3 layers one primer and two paint. Check the instructions for use of the coating or the material safety data sheet msds. And, the ability to predict the thickness of paint helps you control cost. Nov 21, 2014 coating thickness correlates to drytime, recoat time and appearance. Dry film thickness is directly proportional to the volume solids of the coating. Coating thickness shall be measured in accordance with sspc. Understanding coating thickness measurements rawlins paints. This time period or fireresistance rating is based on the applied thickness of the coatings. Wet film thickness is the measured thickness of any applied wet paint that is. Mar 29, 2016 this is how to measure wet film thickness using a wet film thickness gauge, also known as a wet film comb. Each layer from primer to topcoat and individual intermediate layers are exactly specified with a minimum and maximum coating thickness. The dry film thickness dft equals the wet film thickness wft multiplied by the volume solids.
In addition, there are multiple techniques that can be used in the field during the installation to test the wft and. Nov 16, 2016 the dry film thickness gauge has been an essential tool in making sure that coating thicknesses are within specifications. They measure all types of wet organic coatings, such as paint, varnish, and lacquer on flat or curved, smooth surfaces. Paint dry film thickness measurement is addressed on sspcpa 2 and provides information to how to average the readings and determine dft acceptability. Wet and dry film thickness formulae gei international inc. Pounds per ream accurate gsm grams per square meter, accurate micron or mil film thickness inaccurate due to absorption by the web ream size area coated, sometimes not 100% sq ft 144,000 sq in 3000 sq ft 432,000 sq in if not 100% coverage well need to cut out.
The dry film thickness and quantity of material required for a certain fire resistance time r 30, 60, 90, 120 minutes or more depends upon various factors. Dry film thickness dft d this may be known, specified or calculated percentage of solids by volume in coating p this may be known, specified or calculated percentage of reducer by volume added to coating r. A wet film thickness gage should be used by the applicator as the coating is being applied to ensure that the measurement is representative of the calculated wet film before significant solvent. For example, if a coating were 45% solids by volume, its theoretical coverage would be 1604 x 0. Home coating inspection equipment paint inspection coating thicknessdry film coating thicknessdry film dry film thickness gauges are available in any combination of basic, limited memory and full batching,as well as either integral built in probes or separate probes to meet your needs andor your specifications. Being able to predict the thickness of paint has many practical benefits. Dry film thicknesses are generally checked on the complete paint system, although individual films may be checked separately. The relationship between dry film thickness dft and wet film thickness wft to avoid premature protective coating failures is presented. All gauges come complete with precision plastic shims, protective rubber holster with belt clip, wrist strap, 3 aaa alkaline batteries, instructions, convenient carrying case, protective lens shield, long form certificate of calibration traceable to nist or ptb, usb cable, two 2 year warranty. How to calculate dft, wft and spread rate from volume solids of painting product.
Gravimetric measuring the mass and area of the coating to calculate. Optical crosssectioning cutting the coated part and viewing the cut microscopically. Sep 01, 2017 calculating and measuring wet film thickness wet film thickness, or wft is the measured thickness of any applied wet paint that is liquidbased. How to determine dry film density products finishing. The specification indicated 3 layers coat and each layer with dft 3 to 4 mil. Understanding volume solids whats left after the paint. Apr 01, 2009 is there an industry standard for industrial equipment primer and paint dry film thickness dft. The dry film thickness can be calculated using the solids to liquids ratio, also known as the volume solids content.
If you have entered an old account number the password reset email will go to the web account owner. Coating thickness correlates to dry time, recoat time and appearance. It provides vital information as to the expected life of the substrate, the products fitness for purpose, its appearance and ensures compliance with a host of international standards. Paint dry film thickness standards is there an industry standard for industrial equipment primer and paint dry film thickness dft. Substitution placing a steel coupon on the wall and coating it at the same time. Mar 01, 20 learn how to use a wet film gauge, to determine what the dry film thickness will be. In iso 19840 and pspc, the term used is nominal dry film thickness. Dry film thickness is probably the most critical measurement. D823 practices for producing films of uniform thickness of paint, varnish, and related products on test panels. This calculator is designed to aid in the determination of achieved dry coatweight for waterbase and uv coating products.
Paint thickness measurement drywall resources defelsko. The percent solids by volume of a protective coating is. Coating thickness gauge allows you to quickly and accurately determine, for. A correct paint or coating thickness is an important parameter in the surface treatment industry. The society for protective coatings paint application standard no. However, specifications list the required coating thickness as measured from the tops of the peaks of the surface profile illustrated by the blue bar. This is primarily due to poor film thickness uniformity. Paint dry film thickness standards products finishing. Gravimetric measuring the mass and area of the coating to calculate thickness dipping wet film thickness gages into wet paint and calculating dry film thickness using the percent of solids by volume. How to measure dry film thickness using an elcometer 415 paint. D1640 test methods for drying, curing, or film formation of organic coatings at room temperature. Calculate the relationship in percentage of the dry film thickness to the wet film thickness on the several panels.
Caltech engineering services a mumbai india based company, manufacturers, suppliers and exporters of thickness meter. The wet film thickness required would be 2 divided by. It would seem that i would need the density of the coating to calculate this correctly. There are different types of dry film thickness gauges and the most popular works only when the paint is applied to a metal substrate. Nov 05, 2018 dry film thickness gauge, destructive is a measuring tool used to determine dry film thickness by cutting and removing a cross section, making a precise vgroove or geometric cut on the coating and then measuring it with a scaled microscope. Converting dry film thickness to wet film thickness. An important factor in the coating system is the definition and measurement of the dry film thickness dft. In addition, wet film measurements are also very useful for coating systems where the dry film thickness can only be measured destructively. Traditionally a destructive test method is used to determine paint thickness. Wet film thickness gages are used to monitor the thickness of the applied wet coating to achieve a specified dry film thickness. If a coating material is applied until it appears to cover completely without regard to the manufacturers specified thickness, the resultant dry film thickness could be lower than the target thickness for optimal coating performance in a specific environment. Is there an industry standard for industrial equipment primer and paint dry film thickness dft.
Wet and dry film thickness formulae easily convert and calculate the wet and dry film thickness and coverage of coatings applied to a substrate. Coatings must be completely cured prior to performing thickness measurements. Calculating and measuring wet film thickness kta universitykta. Percentage of solids by volume in a coating will usually be known. In the case of paints, the film thickness you have after the paint dries is determined by the proportion of solids to liquid that are in the paint. Jul 01, 2018 dry film density is a bit more complicated. Knowing the coating thickness of dry film is a critical measurement in the coating application process. S the wet coating film must be to achieve the specified dry film thickness. It seems like i have seen 35 mil thickness for both primer and paint for a total dft of 610 mils. The wet film thickness gage, also often referred to as a comb, can be placed in the wet paint or coating and produce an accurate measurement of thickness in a matter of moments. How to achieve desirable dft dry film thickness for waterbased paint. The measurement of the wet film thickness of paints or coatings applied on materials can be very beneficial to determine the appropriate thickness of dry coating. So dry density follows the same density equation, d mv, as wet density. The thickness of the paint film is measured in microns when it is dry.
Wet film combs measure wet film thickness, and are available in a variety of materials including stainless steel, aluminium and plastic, with. The total thickness of the substrate and coating is measured. You are witnessing a dry film thickness measurement on final coat, and it is supposed to be 9 to 12 mils. How to measure dry film thickness using an elcometer 415 paint thickness gauge. How to measure coating thickness as per sspc pa2 using type 2 gauge duration. Additionally, most manufacturers of high performance coatings will warranty coating systems based upon, in part, achieving the proper thickness of each layer and the total coating system. When you measure the wet film thickenss you must do so immediately after you have. A coating thickness gauge also referred to as a paint meter is used to measure dry film thickness. Cure the paint as described in the technical data sheets. How to measure wet film thickness using elcometer wet film.
The principle of electromagnetic induction is used for nonmagnetic coatings on magnetic substrates such as steel. Almost all top performing and protective coatings should meet specific requirements for dry film thickness. The wet film thickness figure given on a specification relates to the thickness of the coating when it has just been applied and is still wet, as soon as the coating begins its drying process solvents and volatiles will be leaving the coating and its thickness will reduce and once cured its dry film thickness. Dry film thickness can be measured on either magnetic steel surfaces or nonmagnetic metal surfaces such as stainless steel or aluminium using a digital coating thickness gauge. Dry film thickness dft wet film thickness mils x %volume solids 100%. How to calculate dft and wft for painting work youtube. The percent solids by volume of a protective coating is used on the coatings technical data sheet and is used to calculate wft and dft. Wet film thickness gage a wet film thickness gage is an inexpensive and easytouse tool that quickly measures coating thickness. Therefore, a direct relation exists between wet film and dry film thickness. Measuring wet film thickness wft to predict the dry film thickness dft the gauge is removed from the wet paint and inspected. Micrometer method for dry film thickness of organic paint coatings astm d1005 test method astm d1005 covers the measurement of film thickness of dried films of paint, varnish, lacquer, and related products using handheld or stationary micrometers. D1005 test method for measurement of dry film thickness of organic coatings using micrometers.
What is a dry film thickness gauge, destructive astm. If you decide to add thinners to the paint you will need to adjust the volume solids in the denominator accordingly. How to achieve desirable dft dry film thickness for. They measure all types of wet organic coatings, such as paint. Today, the primary purpose of ultrasonic testing is to nondestructively measure the total thickness of the paint system, typically in the range of 3 to 5 mils 75 125. Understanding coating thickness measurements rawlins.
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