{"id":40,"date":"2020-03-23T08:56:58","date_gmt":"2020-03-23T08:56:58","guid":{"rendered":"http:\/\/www.airoshotblast.net\/blasting-machines\/?p=40"},"modified":"2026-10-07T09:48:58","modified_gmt":"2026-10-07T09:48:58","slug":"what-isthermal-spray-coating","status":"publish","type":"post","link":"https:\/\/www.airoshotblast.net\/blasting-machines\/coating-gun\/what-isthermal-spray-coating\/","title":{"rendered":"Thermal Spray Coating and Identification of Thermal Spray Technologies"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">Thermal Spray Gun: How It Works, Types, Uses, Abrasives &amp; Safety<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Machine parts and steel structures face wear, corrosion and heat every day. <strong>Thermal spray coating<\/strong> is a proven way to protect them and extend their working life. This guide explains what a thermal spray gun is, how it works, where it is used, which abrasives to choose and how to stay safe.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What is a Thermal Spray Gun?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A thermal spray gun, also called a <strong><a href=\"https:\/\/www.airoshotblast.net\/blog\/103-what-is-metal-spray-gun\">metal spray gun<\/a><\/strong> or <strong>metalizing gun<\/strong>, heats a coating material until it is molten or semi-molten and sprays it onto a prepared surface. The material can be a powder or a wire, and many materials can be used, including metals, alloys and ceramics.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The coating can be very thin, about one thousandth of an inch (0.025 mm), or as thick as one eighth of an inch (about 3 mm).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>What thermal spray coatings are used for:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Protection against corrosion and abrasion:<\/strong> A Zinc Spray Gun or Metallizing Gun applies zinc or zinc alloy wire to protect steel from rust, and a Sandblasting Machine prepares the surface first.<\/li>\n\n\n\n<li><strong>Protection from high temperatures:<\/strong> A Plasma Spray Gun or <strong><a href=\"https:\/\/www.sandblasting.net.in\/spray-gun\/hvof-gun\" target=\"_blank\" rel=\"noopener\">HVOF Spray Gun<\/a><\/strong> can spray heat-resistant materials such as ceramics.<\/li>\n\n\n\n<li><strong>Resistance to general wear and damage:<\/strong> An HVOF Spray Gun gives dense, wear-resistant coatings, and a <strong><a href=\"https:\/\/www.airoshotblast.net\/blog\/102-wire-flame-spray-gun-and-how-does-wire-flame-spray-gun-work\">Wire Flame Spray Gun<\/a><\/strong> suits general wear protection.<\/li>\n\n\n\n<li><strong>Rebuilding undersized parts to their correct dimensions:<\/strong> A Thermal Spray Gun builds up worn parts, and a Metalizing Gun is useful for rebuilding shafts and similar components.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Key benefits:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Accurate control:<\/strong> Coating thickness and properties can be controlled precisely, and results are repeatable.<\/li>\n\n\n\n<li><strong>Wide material choice:<\/strong> Metals, alloys and ceramics can be sprayed.<\/li>\n\n\n\n<li><strong>Flexible operation:<\/strong> Guns can be mounted on automated systems or used by hand for precise work.<\/li>\n\n\n\n<li><strong>Low heat on the part:<\/strong> The substrate stays relatively cool, and cooling systems control any temperature rise.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">How Does a Thermal Spray Gun Work?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The coating material starts as a <strong>powder<\/strong> or a <strong>wire<\/strong>. The gun gives it energy in the form of heat, speed, or both, and carries it to the part. When the molten particles hit the surface, they flatten into small splats and stack in thin, overlapping layers. This forms a strong <strong>lamellar coating<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Cleaning and degreasing:<\/strong> Remove oil and dirt from the part.<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Masking:<\/strong> Cover areas that should not be coated.<\/li>\n\n\n\n<li><strong>Surface preparation and blasting:<\/strong> Use a <strong><a href=\"https:\/\/www.sandblast.in\/product\/sand-blasting-machine\" target=\"_blank\" rel=\"noopener\">sandblasting machine<\/a><\/strong> to clean and roughen the surface so the coating bonds well.<\/li>\n\n\n\n<li><strong>Demasking and cleaning:<\/strong> Remove the masking and clean again.<\/li>\n\n\n\n<li><strong>Masking for coating:<\/strong> Mask again if needed.<\/li>\n\n\n\n<li><strong>Coating:<\/strong> Spray with the <a href=\"https:\/\/www.sandblastingmachine.in\/thermal-spray-gun\" target=\"_blank\" rel=\"noopener\">thermal spray gun<\/a>, building up the required thickness in multiple passes.<\/li>\n\n\n\n<li><strong>Demasking:<\/strong> Remove the masking.<\/li>\n\n\n\n<li><strong>Secondary operations:<\/strong> Deburring or finishing where required.<\/li>\n\n\n\n<li><strong>Inspection and testing:<\/strong> Check thickness, bond strength and quality.<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Key process controls for quality coatings:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Coating material:<\/strong> Composition, particle shape and a steady feed rate in a carrier gas.<\/li>\n\n\n\n<li><strong>Spray gun settings:<\/strong> Heat supplied to the particles, particle exit speed, gas flow, standoff distance (gun to part distance), traverse rate (speed of gun movement), number of passes and spray angle.<\/li>\n\n\n\n<li><strong>Surface and temperature:<\/strong> Cleaning, surface roughness, masking, cooling systems and control of local temperature changes.<\/li>\n\n\n\n<li><strong>Coating system:<\/strong> Acoustic booth to reduce noise, and a dust collector to capture and recycle coating material.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Main Types of Thermal Spray Guns<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Processes differ in how they apply heat and speed, whether they use powder or wire, and how fast and hot the flame is. Each has advantages and drawbacks, and some suit certain coatings better.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>HVOF (High Velocity Oxy Fuel) Gun<\/strong><br>Particles travel very fast, which gives dense, strong coatings with low porosity. It is well suited to wear resistant applications.<\/li>\n\n\n\n<li><strong><a href=\"https:\/\/www.shotblastingmachines.in\/plasma-hvof-spray-gun\" target=\"_blank\" rel=\"noopener\">Plasma hvof Spray Gun<\/a><\/strong><br>Uses an extremely hot plasma flame, so it can spray high-melting-point materials such as ceramics.<\/li>\n\n\n\n<li><strong><a href=\"https:\/\/www.airoshotblast.net\/blog\/99-what-is-flame-spray-gun\">Flame Spray Gun<\/a><\/strong><br>Uses a fuel gas and oxygen flame. It is simple, portable and cost-effective, which makes it popular for general work and field jobs. The <strong>Airo <a href=\"https:\/\/www.airoshotblast.net\/blog\/104-what-is-metalizing-gun\">Metalizing Gun<\/a><\/strong> is an example of a gun used for metal spray work.<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\">Comparison of Thermal Spray Processes (typical industry values)<\/h4>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Property<\/th><th>HVOF<\/th><th>Plasma<\/th><th>Flame<\/th><\/tr><\/thead><tbody><tr><td>Particle velocity (m\/s)<\/td><td>800<\/td><td>300<\/td><td>40<\/td><\/tr><tr><td>Particle\/gas temperature (\u00b0C)<\/td><td>3,000<\/td><td>14,000<\/td><td>3,000<\/td><\/tr><tr><td>Adhesion strength (psi)<\/td><td>&gt;10,000<\/td><td>&gt;700<\/td><td>1,000<\/td><\/tr><tr><td>Oxides (%)<\/td><td>&lt;2<\/td><td>&lt;3<\/td><td>12<\/td><\/tr><tr><td>Porosity (%)<\/td><td>&lt;2<\/td><td>&lt;5<\/td><td>&lt;15<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Where Are Thermal Spray Guns Used?<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Bridges, tanks, pipelines and steel structures (corrosion protection)<\/li>\n\n\n\n<li>Industrial machinery and fabrication work<\/li>\n\n\n\n<li>Worn or undersized parts that need to be rebuilt<\/li>\n\n\n\n<li>Parts exposed to high temperatures or heavy abrasion<\/li>\n\n\n\n<li>Marine and offshore equipment<\/li>\n\n\n\n<li>Both workshops and on site projects<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">What Abrasives Should Be Used Before Thermal Spraying?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A <a href=\"https:\/\/www.sandblast.in\/product\/thermal-spray-coating\" target=\"_blank\" rel=\"noopener\">thermal spray coating<\/a> is only as good as the surface under it. The part must be clean and rough enough for the coating to grip. The right abrasive in a sandblasting machine creates this profile.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Recommended abrasives:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><a href=\"https:\/\/www.sandblastinghopper.in\/product\/aluminum-oxide\" target=\"_blank\" rel=\"noopener\">Aluminium oxide<\/a>:<\/strong> Sharp and hard, and gives a consistent rough profile. It works well in a <strong>Sandblasting Machine<\/strong> or Sand Blasting Pot with a <strong><a href=\"https:\/\/www.gritblast.co.in\/sand-blasting-nozzle\" target=\"_blank\" rel=\"noopener\">Blasting Nozzle<\/a><\/strong>.<\/li>\n\n\n\n<li><strong><a href=\"https:\/\/www.shotblastingmachines.in\/steel-grit\" target=\"_blank\" rel=\"noopener\">Steel grit<\/a> (angular):<\/strong> Reusable and effective for a deep anchor pattern. It is commonly used with a <strong><a href=\"https:\/\/www.airoshotblast.net\/blasting-machines\/shot-blasting-machine\/shot-blasting-machine\/\">Shot Blasting Machine<\/a><\/strong> or blast room.<\/li>\n\n\n\n<li><strong>Garnet:<\/strong> Cuts cleanly with low dust and works well for general blasting. Use it with a <strong><a href=\"https:\/\/www.airoshotblast.net\/blasting-machines\/sand-blasting-machine\/portable-sand-blasting-machine\/\">Portable Sand Blasting Machine<\/a><\/strong> for site jobs.<\/li>\n\n\n\n<li><strong>Silicon carbide or crushed angular grit:<\/strong> Suitable for hard surfaces needing aggressive cutting. Pair it with a durable <strong><a href=\"https:\/\/www.sandblastinghopper.in\/product\/boron-carbide-nozzles\" target=\"_blank\" rel=\"noopener\">Boron Carbide Nozzle<\/a><\/strong>.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Avoid:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Round <a href=\"http:\/\/sandblastingmachine.in\/steel-shots\" target=\"_blank\" rel=\"noopener\">steel shot<\/a><\/strong> used alone, because it peens the surface rather than roughening it. This gives a poor bond when you apply the coating with a metal spray gun.<\/li>\n\n\n\n<li><strong>Silica sand<\/strong>, because it produces dust that causes serious lung disease (silicosis) and is banned or restricted in many places, silica sand is also called <a href=\"http:\/\/blaster.co.in\/quartz-sand\" target=\"_blank\" rel=\"noopener\">Quartz sand<\/a>.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Best practices:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Follow the surface roughness your coating specification requires, so the <a href=\"https:\/\/www.airoshotblast.in\/wire\/zinc-wire\" target=\"_blank\" rel=\"noopener\">zinc wire<\/a> sprayed from the gun bonds firmly to the steel.<\/li>\n\n\n\n<li>Keep the abrasive clean, dry and free from oil and moisture. A <strong>Moisture Separator<\/strong> (air dryer) helps.<\/li>\n\n\n\n<li>Spray soon after blasting, ideally within a few hours, before flash rust forms. Using a <strong><a href=\"https:\/\/www.sandblastingmachine.in\/zinc-spray-gun\" target=\"_blank\" rel=\"noopener\">zinc spray gun<\/a><\/strong> right after blasting gives a stronger, longer-lasting coating.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Important Safety Considerations<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Thermal spraying is safe when done correctly. Follow these precautions:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Respiratory protection:<\/strong> Spray fumes and blasting dust are harmful. Use an approved respirator or air-fed helmet.<\/li>\n\n\n\n<li><strong>Ventilation and dust control:<\/strong> Work in a well-ventilated area and use a <strong><a href=\"https:\/\/www.sandblast.in\/product\/dust-collector\" target=\"_blank\" rel=\"noopener\">dust collector<\/a><\/strong> to capture fine particles.<\/li>\n\n\n\n<li><strong>Eye and face protection:<\/strong> Wear goggles or a face shield with the correct filter lens for the bright flame, arc or plasma.<\/li>\n\n\n\n<li><strong>Hearing protection:<\/strong> When using a thermal spray gun such as the airo metalizing gun, both the gun and the compressed air produce a lot of noise. Operators should always wear ear plugs or ear muffs. An acoustic booth reduces noise further.<\/li>\n\n\n\n<li><strong>Protective clothing:<\/strong> Wear heat resistant gloves, long sleeves and safety boots (<a href=\"https:\/\/www.gritblast.co.in\/sand-blasting-machine\/safety-equipment-for-blasting\" target=\"_blank\" rel=\"noopener\">safety equipment for blasting<\/a>).<\/li>\n\n\n\n<li><strong>Fire and gas safety:<\/strong> Keep flammable materials away, store and handle gas cylinders securely, and keep a fire extinguisher nearby.<\/li>\n\n\n\n<li><strong>Electrical safety:<\/strong> Check cables and earthing, and keep the equipment dry.<\/li>\n\n\n\n<li><strong>Compressed air safety:<\/strong> Inspect hoses and fittings, and never point the gun at people.<\/li>\n\n\n\n<li><strong>Training:<\/strong> Only trained operators should use the equipment, following the manufacturer&#8217;s manual.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Thermal Spray Gun: How It Works, Types, Uses, Abrasives &amp; Safety Machine parts and steel structures face wear, corrosion and heat every day. Thermal spray coating is a proven way to protect them and extend their working life. This guide explains what&#8230;<\/p>\n","protected":false},"author":1,"featured_media":41,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12,15],"tags":[7,6],"class_list":["post-40","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-coating-gun","category-thermal-spray-gun","tag-spray-guns","tag-thermal-spray-coatings"],"_links":{"self":[{"href":"https:\/\/www.airoshotblast.net\/blasting-machines\/wp-json\/wp\/v2\/posts\/40","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.airoshotblast.net\/blasting-machines\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.airoshotblast.net\/blasting-machines\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.airoshotblast.net\/blasting-machines\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.airoshotblast.net\/blasting-machines\/wp-json\/wp\/v2\/comments?post=40"}],"version-history":[{"count":7,"href":"https:\/\/www.airoshotblast.net\/blasting-machines\/wp-json\/wp\/v2\/posts\/40\/revisions"}],"predecessor-version":[{"id":1014,"href":"https:\/\/www.airoshotblast.net\/blasting-machines\/wp-json\/wp\/v2\/posts\/40\/revisions\/1014"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.airoshotblast.net\/blasting-machines\/wp-json\/wp\/v2\/media\/41"}],"wp:attachment":[{"href":"https:\/\/www.airoshotblast.net\/blasting-machines\/wp-json\/wp\/v2\/media?parent=40"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.airoshotblast.net\/blasting-machines\/wp-json\/wp\/v2\/categories?post=40"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.airoshotblast.net\/blasting-machines\/wp-json\/wp\/v2\/tags?post=40"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}