Posted by IFS Coatings on 17 May 2017
What is QC testing
No matter what you’repowder coating, no matter the size of the line and no matter the type of powder or color you’re shooting, everyone wants to do a great coating job. We all work hard to make sure our customers are satisfied and their powder coated product looks great and performs well. Making sure it looks great is one thing, but how do you check that your coated surface is technically good? Quality Control Testing, or QC testing offers up a range of simple, easy to perform tests and performance criteria to ensure you’re powder coated finish is going to do just that – perform well. The really good news is it’s simple, cheap and easy to do.
You know how it goes. You're carefully applying the powder, and of course the color has to match the standard the coating company supplied - that’s what your customer wants. As well as looking great, we also want some basic performance from that coating too. Performing some simple QC tests will ensure that the powder is going to adhere, protect, decorate and perform exactly as it should when it’s on the part. This gives you the confidence to be proud of a high quality and reliable service and leaves your customers with both a great coated piece and a happy experience that will make them want to work with you again.
There are a few simple QC tests that are quick and easy to perform, so let’s take a look at some of those tests, why we need to do them and what we need to look for along the way.
Who Should QC Test?
At IFS we understand quality. As manufacturers and suppliers of high-quality industrial powder coatings, our production facilities and internal quality control systems are designed with superior quality in mind, and we use the most advanced technologies and experienced staff to QC test our powder at the IFS facilities.
We undertake QC testing before, during and at the end of the production of each product we manufacture. BUT… the it doesn’t and shouldn’t stop there. When it comes to applying powder, testing is just as important. Everyone – no matter what you’re shooting or the type of powder operation you have – can perform simple QC for peace of mind. And it's a great attribute and service to sell to your customers!
These simple QC procedures can be done to ensure that the product will perform as per the Technical Data Sheet (TDS) we provide for you. Every powder coating comes with a TDS and it's a great tool to use to check on performance expectations. Make sure your finished coating is at the required level and that your customer will receive the high-quality coating job they ordered.
If you’re not familiar with the TDS here is some insight... at IFS Coatings, we produce a tech data sheet for each product we make. On that TDS, you’ll find a description of the product, the typical physical properties you can expect the powder to provide if applied properly, such as gloss level, hardness, flexibility and adhesion, application tips, cure schedule and storage requirements.
The TDS gives you a basic level of performance – a quality spec – that the powder can achieve if applied properly. They provide a lot of useful information to you, but you shouldn’t always assume the powder will meet the spec - applying it correctly is a big part of achieving that performance. Here are some of the simple tests that can be performed and what to watch out for.
What are the simple tests that you should be doing?
So now we know who should be QC testing and we know why we do it, but what should we be testing for and how? There are several cheap, easy to perform tests that can make the difference between a satisfied customer and an unsatisfied customer. No one wants to send out a coated product that looks great but doesn't perform. So, to the tests...
Film Thickness Testing: The Film Thickness Meter

Image Credit: PosiTector
Film thickness – and a constant, level thickness at that – is important. It affects how the coating looks (no one wants the finished powder coated surface to have a patchy effect) but also overall performance.
The simple way to check film thickness is with a Film Thickness Meter or Gauge.
Best used on a flat surface, they’re easy to use. With most meters, you simply press it to the surface, hold it there a few seconds and get a reading. The reading will tell you what the film thickness at that specific place is. You should repeat the test in several places across the part. It's going to vary, (hopefully only slightly), so you should perform the test in several places to get an average and be sure you're in the required film thickness range. Dave Merritt. one of our technical service managers, shows you exactly how to do this and what to watch out for in this short explainer video.
There are a range of meters available. The latest and greatest can produce the film thickness grade information as soon as a surface is touched, others take a little longer and many are magnetic.
Knowing your substrate is also important. There are meters that can measure coating thickness on aluminum or steel but be sure that yours can test for both as certain gauges won't measure aluminum. One to watch out for!
Why is this important? Well, most gauges are based on the magnetics of steel or the rebound of the signal from steel. Obviously aluminum doesn't react the same way, so a different type of gauge or a combo gauge will need to be used if you're going to be measuring both substrates.
As with most things in life, you can spend as much or as a little as you like for a film thickness meter. You can certainly find a cheaper film thickness gauge around the $100 mark. The little magnetic ones and the low film mils from one to three mills, are pretty accurate and can certainly do the job. That’s pretty inexpensive and may be all you need. A middle of the range, high quality, good working gauge that you can calibrate and zero out for bare metal can range from $400-$800. Of course, if you want to go all out you can also spend $2,000!
Film Thickness Testing - What makes it fail?
The thing to remember is that film thickness, of course, is a range. Failure, therefore, would be in where there is too little or too much, or too much variation. Too little results in poor appearance, incomplete coverage of the substrate and failure of other tests such as corrosion and color. On the other end of the scale, too much can lead to poor appearance and failure of other tests such as impact and flexibility.
Solving film thickness issues:
Fortunately solving film thickness issues in powder coating is pretty simple. Check out the summary table which explains the causes and how to solve them.
Regular testing with your film thickness gauge will help you ascertain if you've mastered good application technique and have solved the problem.
Problem | Possible Cause | Solution |
---|---|---|
Uneven film thickness | Distance between gun and part is too close | Move the gun further away from the part. |
Powder is delivered inconsistently | Adjust the equipment/air setting to its optimum. | |
Irregular voltage | Check the entire system (from voltage source to electrode) to ensure continuous electrical charge. |
The Solvent Rub Test
How about another example? Let’s take a solvent rub test. This test method is used to measure the degree of cure of a coating. Making sure your coating is fully cured is super important – it simply won’t perform if it’s not! It’s done by checking the degree of resistance the cured film demonstrates to a solvent.
The two main solvents used in the rub test are acetone and more commonly, Methyl Ethyl Ketone (MEK), which is what most coaters use.
The MEK test is an ASTM standard test, but again, it's simple and easy to do. The test requires you to take a Q-Tip or a cotton swab and then wet that swab with acetone or MEK before firmly pushing on the product surface and rubbing back and forth. In general, 25 double rubs are performed. Pressing all the way up and all the way down is classed as one double rub. The number of rubs that a coating will pass will vary between product type or the resin system used in it. Some powder product types, like epoxies, will handle 50 double rubs.
On completing your 25 double rubs there is a chance that you will see some slight de-glossing of the coating. Most of the time a little bit of de-glossing of the coating is still a pass.However, what we would really call a fail is when you really start to get down into that coating and the coating is removing onto your Q-Tips.
A little bit of color on the end of the Q-Tip is okay, but if you really feel like the coat is softened and it's coming away and your Q-Tip is covered, you've got a problem. It's not cured properly.
There is one little caveat to the test, however. There are certain resin systems that from past experience don't do as well with the solvent resistance test whether they are fully cured or not. It’s something our technical service reps have seen a number of times. In this case, a solvent rub test would fail miserably and of course, we then incorrectly assume the coating is not cured.
However, they then discovered that the resin itself doesn’t perform in the solvent test, cured or uncured. So it’s always best to check with your manufacturer if you’re testing a new product with a different resin system.
The solvent rub test is quick, simple, cheap and easy to perform! What's not to love? Check out this short explainer video, where Dave Merritt, one of the IFS Technical Managers, shows you how to perform it and what to look for. Seeing is believing!
So what should you do if the test does fail? Recheck your oven temperature and dwell time. Did the part have time to reach temperature and THEN spend the required amount of time in the oven? We know what the air temperature is in the oven, but the part won’t instantly be at temperature the moment it goes in – especially with thicker parts. Make sure you allow your powder coated parts time to get up to temperature and then cure. You may be able to put the part back in the oven and ‘top up’ the cure, or you may need to recoat and re-cure. You can always check with IFS for technical advice if you’re having recurring problems.
Solvent Rub Checks - What makes a fail?
Additionally, If you looked at the results of your solvent rub test and you’re seeing a fail, there could be several different reasons, but the most common are typically going to be the temperature and/or the time of which the powder was cured.
Check the tech data sheet - it's going to give you the oven temperature needed to cure the coating and the amount of time it needs in the oven. For example, if a powder was applied and then failed a QC test, you may want to go back and turn the oven temperature up another 10 or 15 degrees to see if that resolves the problem. Alternatively, it may be that it did not spend enough time in the oven. Or, as previously mentioned, perhaps the part had not been given the time to reach temperature, as it’s only when the part reaches temperature, that the cure time begins.
What’s more, don't forget to take into account different thicknesses of metals used on various jobs. Of course, the thicker the metal, the longer it's going to take to come up to temperature and for that temperature to hold to get a full cure.
So, If you do have a failure, start looking in your oven. Am I leaving it in there long enough? Is the temperature high enough? Have I performed oven maintenance so I know it’s performing as required?
Experience
A note regarding the above points is that a lot of that solvent testing comes back to experience. There are things that you may let go with a little transfer, there are other things you won't let go with a little transfer without knowing the full background of what the product will or won't do. It's a general test and over time you will get to know what is working and what isn’t.
The Pencil Hardness Test
Once you’ve established good cure, the ‘pencil hardness test’ is an effective method to test coatings for their hardness and their scratch resistance. ASTM test method D3363 allows the use of pencils of a known hardness to be moved over the surface of the test sample at a fixed angle and pressure to perform the test.
As you may well be aware, pencils come in a hardness range with a ‘B’ pencil being the softest category and ‘H’ pencils being the hardest. Within each category, there is also a numerical domination, such as 2H or 6H, which indicates hardness within that category. As the numbers increase so does the hardness, so 4H is harder than an H pencil.
With good quality powder coatings, you'll usually end up in the H range. So, if the TDS or your customer requires a 2H pencil hardness, then that’s the pencil that should be used,
To complete the test, you simply sharpen your pencil, then create a flat end with a piece of sandpaper and place it at a 45-degree angle to the coated surface. Press it down into the coating and then push. If that pencil cuts down to the metal, then it failed that test. If there is no scratch on the paint, then it is considered a pass. See how it's done in this short video, where Dave performs the pencil hardness test and explains what to look for.
This is a simple and cheap test that is easily performed to demonstrate the quality of your application and there are a few things to consider...
Get yourself a good set of pencils and remember that old pencils, junk pencils, or not a name brand are likely to give you different results all day long. If you’re going to use a pencil test, we recommend you buy a decent turquoise brand pencil and for consistency, always use that brand. You can buy them at most art stores and they are available in the full hardness range. Think about testing an additionally coated piece till it fails – you may find that the hardness rating you can offer goes beyond what is required – a great selling point for you!
Also, remember that each person and pencil may get a different result because of the manual nature of the process. Being consistent with the pencils you are using and the pressure that you apply will ensure fair results. Regularly performing the test will help you get to know your own scales and strengths.
Pencil Hardness Testing - What makes it fail?
A pencil test will most likely fail as a result of two things... Under cure or over cure. So again, be sure tolook at the tech data sheet for the guidance on the correct curing details, and think about time and temperature in the oven.
Crosshatch Adhesion Test
The Cross Hatch Adhesion Test is a very popular test to assess the adhesion of the coating and essentially provides a visual assessment of the quality of the bond to the substrate. This test is easy and a must for checking powder coating adhesion!
The test is performed by making a series of cuts through the coating. There are kits available for this as it is important that you use thepreferred blade devices for each film. Generally, 5 cuts are made with 5 sharp blades reasonably close together in one direction.
Then cut across that direction so you've cut through the paint to the metal five times left and right, and five times up and down. It should look like a tic-tac-toe grid when you’re done.
Once you have your tic-tac-toe grid, the pressure sensitive adhesive tape is applied to that area, pressed down real good and then the tape is removed. That area is then judged to see if any paint was removed from the cross-sections that were cut. No coating removal is a good pass. If there is a little corner here or there that has been pulled off it would likely still be ok and would pass the test. Check out Dave showing you how to perform the cross hatch adhesion test in this short video.
To determine performance, there is an ASTM rating scale to make the decision - a 5B result is usually the sweet spot.
The best way to make sure that you have been doing the test correctly is to get an official cross hatch adhesion test kit and maintain it. That way you are guaranteed quality and accurate test results each and every time. Kits cost between $30-$100.
Remember this is a simple, fast and cheap test to perform, and we highly recommend you get hold of a solid adhesion testing kit and make it part of your QC process.
Crosshatch Adhesion - What makes it fail?
What makes the coating fail a crosshatch adhesion test? Well, it is most likely one of two possible scenarios. One, you could have bad pre-treatment or a poor substrate - the substrate is not clean enough or has not been correctly prepared, which leads to adhesion failures. Therefore checking your pretreatment process, the quality and cleanliness of the substrate should be your first port of call.
The second reason for a testing fail could be if the paint is under cured. Check out the simple ways to check for that we covered in the solvent rub testing section.
Visual Checks
So far we have covered QC tests that require some hands-on tools and physical movement but we can also learn a lot from simple visual checks. Yes, it sounds pretty obvious and super simple but there are still a number of things to consider when completing visual checks. Where should you look at it? On the floor? Outside? Inside? Here are some points to take note of...
It’s important that your visual tests are consistent with how your customer will check and use the coated product. If your customer is going to look at the product in one light then you should test it in the same light.
If you want more of a controlled testing system than going outside or inside, many job shops use light boxes to control the light. This is more of an investment, as light boxes range in cost, but they will provide consistent results. The other element to consider with lighting is the distance from which you are viewing the surface, especially when checking for any type of surface defects. You will get a different result if you look at a 90-degree angle at arm’s length than from a 45-degree angle closer up. Our advice would be to do the visual test with lighting in an office-type setting, out on the shop floor and outside in the daylight too – cover all bases.
Mica metallics, for example, can look like a different color in the light or the dark which can produce conflicting opinions on the color, so it is essential that all parties are aligned and that the test measurements and conditions are clearly stipulated. Not only do you need to consider the light, but also the angle at which you will judge or compare the coating.
Of course, you could be opening a can of worms if there are too many variables at play, but visual tests are what your customer will instantly do when they receive the coated part, so agreeing what it should look like up front is important.
Visual Checks - What makes a fail?
Visually you could see all manner of defects in the paint – craters, orange peel, window framing…the list goes on. Each of those can be a result of a change or problem in the application process, and we cover each of them in our dedicated blogs on appearance issues and application issues. Right now, let’s deal with the basics – color and gloss.
Depending on the color being used, the results may vary slightly. Generally speaking, if it darkens or yellows and you see some de-glossing, there's a good chance the coating is over-cured. If it is lighter than it should be or bluer in shade and your gloss is too high, there is a good chance the coating is under cured.
If you’re seeing yellowing to the color it could be due to a film thickness variation, or that the coating is over cured or could even be caused by oven exhaust. Problematic, but all easy to check and solve.
Summary
These are just a handful of Quality Control tests that are cheap, easy and simple to perform. You can and should be implementing them regularly to ensure high-quality processes, products, and happy customers. At the end of the day, they will give you peace of mind that the coated parts going out of your door are acceptable. What's more, the more you do them, the better you get at performing consistent tests and judging the results.
You may not want to do them all or may feel that not all are applicable to every part you coat, but the solvent rub test and cross hatch adhesion test are a basic minimum which will give you great results. Of course, on a visual level you will want to see that the color and gloss is right, if not, we all know the customer will be the first one to complain! Keep your reputation as a first class coater in check by visually inspecting each job that leaves your shop.
Fortunately, there isn’t anything difficult about any of the tests above. They are simple and relatively cheap to perform. As with most things, however, consistency is key. Make sure you, your customers and your colleagues or employees are testing in the same way; in the same light, at the same angle, with the same pencils, kits, and meters etc. is key. Remember, experience will count for a lot over time, so the more you test, the more comfortably and quickly you will be able to make a decision on how to pass or solve any questionable results.
For more information, feel free to reach out to our team at coatingsinfo@ifscoatings.com.
FAQs
How do you test the quality of powder coating? ›
Gloss Measurement
This test is performed using a gloss meter, which shines a light onto the surface of the part at a fixed angle, then measures the amount of light reflected off it. If the measurement is out of tolerance, it may be an indication that the powder coating has not cured properly.
There are three different procedures to assess the resistance of the coating to separate from the substrate and provide different adhesion analysis of the film: cross-hatch test, scrape adhesion test and a pull-off test.
How do you calculate powder coating coverage? ›Weigh the bag before and after to measure how much powder was applied. Then apply the following formula: Powder Deposited (the weight of the powder on the part) divided by Powder Applied (the weight of the powder in the bag) multiplied by 100 will give you the basic transfer efficiency percentage.
What should be checked before specifying a powder coated finish? ›Environmental Considerations
So it is vital that before specifying a given powder coating, the environmental influences on the project are understood. The resistance of each powder coating to the physical and chemical extremes of these climates determines the most suitable product.
ISO 8130-5:2021 - Coating powders — Part 5: Determination of flow properties of a powder/air mixture.
What is the ASTM standard for powder coating? ›ASTM D3451 : Standard Guide for Testing Coating Powders and Powder Coatings.
What is normal powder coating thickness? ›Coating thickness can range from 20 to 100 microns (1 to 4 mils).
How much does powder coating cost per hour? ›Electrostatic painting costs an average of $60 per hour, but you could pay between $25 to $100 per hour. The national average for powder coating parts is $680, with a typical range of $340 to $1040.
What temperature should powder coating be? ›Unlike conventional liquid paints, which require an evaporating solvent for application, powder coating uses electrostatic application methods before being cured under high heat. Most powders require baking at around 350-400 degrees Fahrenheit for 10-20 minutes to fully cure.
What should the moisture content be in powder coating? ›Relative Humidity in Powder Coating Areas should be maintain 40+5% RH at 24+5ºC.
What are powder coating defects? ›
Poor powder coating adhesion: high thickness of the phosphate coat, poor de-greasing, presence of contaminants and low quality steel cause poor adhesion of powder coating to substrate.
What metals Cannot be powder coated? ›...
Here are some metals that receive great results after this refinishing process:
- Aluminum.
- Stainless steel.
- Mild steel.
- Galvanized steel.
- Electroplated steel.
- Steel alloys.
The two most widely used types of powder coating are TGIC Polyester and Urethane Polyester. Both types of powder coating provide excellent wear resistance and outdoor durability. Polyester Urethane powder systems provide excellent chemical resistance.
What are the two basics of coating? ›Adhesion: the coating must adhere to the product, meaning there must be a degree of affinity between the ingredient and the product. Coalescence: in case of a liquid, the multiple droplets may merge to form a uniform continuous layer.
What are four types of coatings? ›Here, we'll describe the benefits and tradeoffs of four of the most common generic coating types: Epoxies, polyurethanes, polysiloxanes and zinc-rich primers, providing examples of how each might be used in a total coating system.
What industry code is powder coating? ›NAICS Code 33281 - Coating, Engraving, Heat Treating, and Allied Activities.
What is the maximum thickness of powder coating? ›Coating thickness can range from 20 to 100 microns (1 to 4 mils). The most significant challenges of UV-curing are the current cost of the powders required, as well as a need to position the UV light to ensure 100% coverage.
What is the ratio of powder to air in powder coating? ›For powder coating a flat surface with a single coat of powder, you generally want to leave the Kilovolts set high in the 80 – 100 KV range and if your powder coating unit allows you to control microamps, limit microamps to 70-80. Powder to air mix will usually be set around 70%.
Are there different grades of powder coating? ›Choosing the Right Color
Before you settle on a color, choose the right powder coating type because they come in different grades with some fit for exteriors and others fit for interiors.
The standard range of powder coating thickness falls around 40 – 80 microns, though specific recommended ranges will differ depending on the powder supplier and the context in which the coating is being applied.
What is ASTM A vs ASTM B? ›
The A prefix in an ASTM specification indicates Ferrous material; the B prefix indicates a Non Ferrous material. The ASTM standards are the most widely used in the United States for steel products.
What happens if powder coat is too thick? ›Film thickness and coverage truly affects the overall finish of a coating. Too thick, and you will run into issues like orange peel or sagging; too thin, and you will be able to see the substrate – and any blemishes on it – easily through the film.
What is the best setting for powder coating? ›A good starting point is a setting of 50 to 80 kV for applying a single coat (or the first coat) to an uncoated part. When working with Faraday cage areas, turn down the voltage. When applying a second coat, a lower kV setting can give the best results.
What pressure do you use for powder coating? ›Powder Coating uses very low pressures. Most often, you will be using the 5-10psi range. When shooting complicated parts with lots of recessed areas (Faraday cage areas), it is best to set the psi just high enough for the powder to spray out of the gun. Lower PSI will help to achieve coverage in the Faraday areas.
What is the formula for powder coating cost? ›Using these assumptions, the formula for ACR = 192.3 x Material Utilization / Film Thickness x SG = Square Feet Per Pound of Powder. Don't worry about memorizing the formula -- we've also included a comparative calculator on this page.
Is there money to be made in powder coating? ›Starting a powder coating business can be a profitable and rewarding endeavor, especially with the growing demand for these services across various industries. But if you're going to capitalize on this rapidly growing opportunity, make sure you do it correctly.
How much does it cost to powder coat 4 rims? ›On average, powder coating rims will cost between $400 to $1200 for a set of four wheels. Large wheels or wheels with curb rash require extra work to refinish and raise the cost of powder coating.
Can you overcook powder coat? ›If you overcure your coating, then it can become brittle. Sometimes this overcuring will show in the appearance of the finish, giving a gold or yellow hue to it. Most of the time, issues with overcuring arise from leaving parts in the curing oven for too long, rather than baking them at temperatures that are too high.
Can you put too much powder coat? ›The excess material can also start to peel up and develop the dread orange peel texture that ruins a shiny finish. If your parts have lots of edges and cutouts, make sure you go to an experienced powder coating specialist. Basic tools sometimes have flow issues that make picture framing much more likely.
Will powder coat cure at 200 degrees? ›Most powder coatings normally cure at temperatures of around 200°C (390°F) maintained for 10 to 15 minutes, before being set aside and given time to cool. The exact temperature and the length of time required to cure can vary depending on the manufacturer's specifications.
How many layers of powder coating? ›
As a powder coater, you may need to apply two coats for a variety of reasons whether for protective reasons or appearance applying a second coat of powder is important to know how to do well.
What is the shelf life of powder coat? ›How long can powder be stored? If kept in these optimal conditions, powder should have no problem maintaining a shelf life of 6-8 months and perhaps longer. Using powder that has been stored beyond the 6-8 month shelf life can sometimes cause issues.
How many mils should powder coat be? ›It can be measured with proper equipment (film thickness gauge). To achieve an optimum effect and reduce voids exposing bare metal, a general recommendation is that powder coating is applied at a minimum film thickness of 2.5 – 3.0 mils.
What causes pinholes in powder coating? ›Pinholes develop from a process called “outgassing.” Pinholes occur during the cure – as the part heats up, gasses that are trapped on or inside the part escape through the powder, causing holes or bubbles in the finish.
What causes orange peel in powder coating? ›'Orange peel' can occur when the surface has not been prepared properly before the coating is added. The way that coating is applied can also be a cause, as can the way it is cured after application. Surfaces can be prepared for powder coating with sandblasting or immersion in zinc or phosphate.
What does flash mean in powder coating? ›Description: Flash Rust is a light, coppery rust. This color is a polyester top coat powder coat and has a high gloss finish.
What is the best metal to powder coat? ›- Steel alloys.
- Stainless steel.
- Galvanized steel.
- Mild steel.
- Aluminum.
- Electroplated steel.
Cleaning and priming surfaces are crucial to the successful outcome of the powder coating process. Powder coating will bond better when the material it's applied to is clean. To ensure surfaces are as prepped as possible, there are a number of steps that can be taken.
How hazardous is powder coating? ›Powder coating products and materials are classified as substances that are hazardous to health because they are respirable (breathable) dusts. The dust is very fine and cannot always be seen, so it can be absorbed deep into the lungs. The majority of powders can result in health effects with significant exposure.
How do you check gloss level of powder coating? ›First, the test specimen is measured with the 60° geometry. The 60° geometry should be used if the gloss reading is between 10 and 70 units. If the 60° gloss is higher than 70 units, the 20° geometry will be advantageous. If the 60° gloss is lower than 10 units, the 85° geometry should be used.
What is quality powder coating? ›
Powder coating is a dry coating process used as a metal finish mostly on industrial equipment. Powder coating is applied as dry powder through an electrostatic process, then cured with heat. It is well known for providing high-quality finishes in terms of both functionality and overall look.
How do you test coating durability? ›A coating is applied to the substrate, and the specimen is mounted to a Martindale Abrasion Tester. The material is then subjected to rubbing in a figure-eight motion until failure or after reaching the manufacturer's specified number of rubs, after which the substrate is evaluated.
What are the three types of powder coating? ›Some of the most popular types of powder coating include: Epoxy Powder Coatings; Polyester Powder Coatings; Hybrid Powder Coatings.
What is the strongest powder coat? ›Epoxies. Epoxies were the first widely used powders. They are very durable, offer excellent hardness and have arguably the best chemical and corrosion resistance of all available powders.
What is the ASTM standard for gloss test? ›Scope: Specular Gloss is a measure of the light reflected by the surface of a material. Gloss can be inherent in the material, a result of the molding process, or a result of surface texture.
How do you increase gloss level in powder coating? ›Generally, using fillers in powder coating that have very small particle sizes will achieve high gloss levels. As particle sizes increase, the gloss level drops. You can fine-tune of gloss levels in powder coating through the choice of fillers, such as barium sulphate and ATH (aluminium trihydrate).
How long to test salt spray for powder coating? ›The standard time before rusting is usually observed in a salt spray test on powder coating is around 500 hours.
What temperature is powder coating good? ›The most common powder coatings can withstand temperatures between ambient to 200°F, although most are on the lower end of the spectrum. These general powders will do the trick for most typical applications, but may be susceptible to significant color change and other issues once you start pushing that 200°F+ range.
What temperature is powder coating done? ›The process of spraying is the recommended application to ensure a uniform finish. The final step is exposing the metal to high temperatures to strengthen the coated finish bond. The typical temperature for heating powder coating is 200 degrees Celsius (or 390 degrees Fahrenheit).
Why does powder coating fail? ›Inadequate Curing
Even if the substrate is correctly pre-treated, the powder coating may break down if it is not cured adequately. Powder coating takes a certain amount of time at a particular temperature to cure properly and powder that is under-cured will not be the most durable even though it may appear intact.
What is the shelf life of powder coating? ›
When stored properly, the storage life should be more than six months from receipt. Experience has shown that many products can remain useful for periods of up to several years.
How many years does powder coating last? ›Powder coating can last up to 40 years depending on the preparation, type of coating used, materials and treatment process. While most powder coatings are highly durable, weather-resistant and provide years of high-traffic use, certain factors can significantly accelerate fading and performance.