{"id":40,"date":"2026-03-26T00:18:48","date_gmt":"2026-03-26T00:18:48","guid":{"rendered":"https:\/\/beginnerweldertips.com\/?p=40"},"modified":"2026-03-26T00:43:13","modified_gmt":"2026-03-26T00:43:13","slug":"how-to-fix-porosity-in-mig-welds-simple-welder-friendly-guide","status":"publish","type":"post","link":"https:\/\/beginnerweldertips.com\/?p=40","title":{"rendered":"How to Fix Porosity in MIG Welds (Simple, Welder-Friendly Guide)"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\"><strong>Quick Answer (Straight to the Point)<\/strong><\/h2>\n\n\n\n<p>You fix porosity in MIG welds by:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Improving your shielding gas coverage<\/strong><\/li>\n\n\n\n<li><strong>Cleaning the metal before welding<\/strong><\/li>\n\n\n\n<li><strong>Reducing stickout to 3\/8&#8243;<\/strong><\/li>\n\n\n\n<li><strong>Checking for gas leaks<\/strong><\/li>\n\n\n\n<li><strong>Avoiding drafts or wind<\/strong><\/li>\n\n\n\n<li><strong>Running the correct voltage and wire speed<\/strong><\/li>\n<\/ul>\n\n\n\n<p>Porosity happens when <strong>air gets into the weld puddle<\/strong>, so the goal is to keep oxygen, moisture, and contamination OUT of your arc.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/i.redd.it\/u52oakk6gwl11.jpg\" alt=\"You can tell its porous because of the way it is. : r\/Welding\"\/><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">What Porosity Is (and Why It Ruins Welds)<\/h1>\n\n\n\n<p>Porosity is when <strong>tiny gas pockets<\/strong> get trapped inside the weld.<br>It looks like:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Pinholes<\/li>\n\n\n\n<li>Tiny bubbles<\/li>\n\n\n\n<li>Swiss-cheese-looking cavities<\/li>\n<\/ul>\n\n\n\n<p>These pockets <strong>weaken the weld<\/strong> because the metal isn\u2019t solid all the way through.<\/p>\n\n\n\n<p>Simple explanation:<br>\ud83d\udc49 If your weld is full of holes, it can\u2019t support the load.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Step-by-Step Fixes (Do These in Order)<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>1. Fix Your Shielding Gas Coverage (Most Common Cause)<\/strong><\/h2>\n\n\n\n<p>Your weld puddle needs a clean gas blanket.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Check your gas flow:<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Set it to <strong>20\u201325 CFH<\/strong><\/li>\n\n\n\n<li>Too low \u2192 porosity<\/li>\n\n\n\n<li>Too high \u2192 gas turbulence pulls air in<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Confirm the gas is actually flowing:<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Valve open<\/li>\n\n\n\n<li>Regulator not stuck<\/li>\n\n\n\n<li>Hose not kinked<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Keep wind and drafts away:<\/strong><\/h3>\n\n\n\n<p>Even a small breeze steals your gas.<br>Weld inside or use a windbreak.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>2. Reduce Your Stickout (Keep It at 3\/8&#8243;)<\/strong><\/h2>\n\n\n\n<p>Long stickout = weak gas coverage.<\/p>\n\n\n\n<p>If you&#8217;re welding with <strong>1\u201d of stickout<\/strong>, you\u2019re basically welding with no shielding.<\/p>\n\n\n\n<p><strong>Fix:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Hold the gun closer<\/li>\n\n\n\n<li>Aim for <strong>3\/8&#8243; to 1\/2&#8243;<\/strong> max<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>3. Clean the Metal Thoroughly<\/strong><\/h2>\n\n\n\n<p>Dirty metal traps moisture and contaminants that turn into porosity.<\/p>\n\n\n\n<p>Remove:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Rust<\/li>\n\n\n\n<li>Paint<\/li>\n\n\n\n<li>Galvanizing<\/li>\n\n\n\n<li>Mill scale (heavy)<\/li>\n\n\n\n<li>Oil\/grease<\/li>\n\n\n\n<li>Moisture<\/li>\n<\/ul>\n\n\n\n<p>Use:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Grinder<\/li>\n\n\n\n<li>Flap disk<\/li>\n\n\n\n<li>Wire brush<\/li>\n<\/ul>\n\n\n\n<p>Clean metal = clean weld.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"573\" src=\"https:\/\/beginnerweldertips.com\/wp-content\/uploads\/2026\/03\/dirty-metal-vs-clean-metal-1-1024x573.jpg\" alt=\"\" class=\"wp-image-41\" srcset=\"https:\/\/beginnerweldertips.com\/wp-content\/uploads\/2026\/03\/dirty-metal-vs-clean-metal-1-1024x573.jpg 1024w, https:\/\/beginnerweldertips.com\/wp-content\/uploads\/2026\/03\/dirty-metal-vs-clean-metal-1-300x168.jpg 300w, https:\/\/beginnerweldertips.com\/wp-content\/uploads\/2026\/03\/dirty-metal-vs-clean-metal-1-768x430.jpg 768w, https:\/\/beginnerweldertips.com\/wp-content\/uploads\/2026\/03\/dirty-metal-vs-clean-metal-1-1536x860.jpg 1536w, https:\/\/beginnerweldertips.com\/wp-content\/uploads\/2026\/03\/dirty-metal-vs-clean-metal-1.jpg 1600w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>4. Check for Gas Leaks<\/strong><\/h2>\n\n\n\n<p>Leaks kill shielding.<\/p>\n\n\n\n<p>Look for:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Loose fittings<\/li>\n\n\n\n<li>Cracked hoses<\/li>\n\n\n\n<li>Bad O-rings<\/li>\n\n\n\n<li>Leaky regulator<\/li>\n<\/ul>\n\n\n\n<p><strong>Fix:<\/strong><br>Spray soapy water on the connections.<br>If it bubbles, it\u2019s leaking.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>5. Fix Your Travel Speed<\/strong><\/h2>\n\n\n\n<p>Traveling too fast \u2192 pushes gas away \u2192 porosity<\/p>\n\n\n\n<p>Traveling too slow \u2192 overheats and destabilizes the arc<\/p>\n\n\n\n<p><strong>Fix:<\/strong><br>Find a steady pace where the bead forms a smooth, even puddle.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>6. Set Correct Voltage &amp; Wire Speed<\/strong><\/h2>\n\n\n\n<p>Wrong settings = turbulent arc \u2192 sucks air in.<\/p>\n\n\n\n<p><strong>If you&#8217;re popping and sputtering:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Increase voltage<\/li>\n\n\n\n<li>Reduce wire speed<\/li>\n<\/ul>\n\n\n\n<p><strong>If your arc is roaring too hot:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Reduce voltage<\/li>\n<\/ul>\n\n\n\n<p>You want a smooth <strong>\u201csizzling bacon\u201d<\/strong> sound.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>7. Use the Right Gas &amp; Wire<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Best gas for MIG on steel:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>75\/25 Argon\/CO\u2082<\/strong><\/li>\n<\/ul>\n\n\n\n<p>100% CO\u2082 works but can increase spatter and arc turbulence if settings aren\u2019t dialed in.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Best wire:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>ER70S-6<\/strong><\/li>\n\n\n\n<li>Fresh, clean wire (rusty wire = porosity)<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Common Mistakes That Lead to Porosity<\/h1>\n\n\n\n<p>Avoid these and you&#8217;ll fix 90% of porosity issues:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>1. Welding in a breeze<\/strong><\/h3>\n\n\n\n<p>Wind is the #1 porosity killer.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>2. Long stickout<\/strong><\/h3>\n\n\n\n<p>Kills gas coverage instantly.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>3. Dirty metal<\/strong><\/h3>\n\n\n\n<p>Contaminants vaporize and become trapped in the weld.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>4. Wrong gas flow<\/strong><\/h3>\n\n\n\n<p>Too low: no coverage<br>Too high: turbulence<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>5. Using rusty or wet wire<\/strong><\/h3>\n\n\n\n<p>Bad wire = instant porosity<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>6. Moisture on metal<\/strong><\/h3>\n\n\n\n<p>Welding wet steel creates steam inside the bead.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>7. Compromised gas hoses<\/strong><\/h3>\n\n\n\n<p>Leaks dilute the shielding gas.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Tools You\u2019ll Need to Fix Porosity<\/h1>\n\n\n\n<p>Keep these on hand:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>MIG welder<\/li>\n\n\n\n<li>75\/25 Argon\/CO\u2082 tank<\/li>\n\n\n\n<li>Regulator &amp; flowmeter<\/li>\n\n\n\n<li>Angle grinder<\/li>\n\n\n\n<li>Flap disk \/ grinding wheel<\/li>\n\n\n\n<li>Weld wire (ER70S-6)<\/li>\n\n\n\n<li>Wire brush<\/li>\n\n\n\n<li>Soap-water spray bottle (leak test)<\/li>\n\n\n\n<li>MIG pliers<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Pro Tips From a Welder<\/h1>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Pull your wire out 1\/2&#8243; before striking<\/li>\n\n\n\n<li>Avoid welding near garage doors, fans, or wind<\/li>\n\n\n\n<li>Keep your nozzle clean \u2014 spatter buildup restricts gas flow<\/li>\n\n\n\n<li>Don\u2019t bury your nozzle in the weld; let gas flow evenly<\/li>\n\n\n\n<li>Replace your nozzle if clogged or damaged<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">FAQ: How to Fix Porosity in MIG Welds<\/h1>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>What causes tiny pinholes in MIG welds?<\/strong><\/h3>\n\n\n\n<p>Most commonly:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Long stickout<\/li>\n\n\n\n<li>Low gas flow<\/li>\n\n\n\n<li>Dirty metal<\/li>\n\n\n\n<li>Wind\/drafts<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Why do I get porosity only at the start of my weld?<\/strong><\/h3>\n\n\n\n<p>Your gas coverage hasn\u2019t built up yet.<br>Hold the trigger <strong>1\u20132 seconds<\/strong> before striking the arc to pre-flow gas.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Can bad wire cause porosity?<\/strong><\/h3>\n\n\n\n<p>Yes \u2014 rusty or oily wire will contaminate the weld and create holes.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Why do I get porosity when welding outside?<\/strong><\/h3>\n\n\n\n<p>Wind blows away shielding gas.<br>Use a barrier or increase CFH slightly (25\u201330), or switch to flux core.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Will porosity weaken my weld?<\/strong><\/h3>\n\n\n\n<p>Absolutely.<br>Porosity creates internal voids and can cause weld failure especially under load.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Can you weld over porosity to fix it?<\/strong><\/h3>\n\n\n\n<p>No \u2014 grinding it out is the proper fix.<br>Then re-weld with correct settings.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Bottom Line<\/h1>\n\n\n\n<p>Porosity means <strong>air or contamination is getting into your weld puddle<\/strong>.<br>To fix it:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Use <strong>proper gas flow<\/strong><\/li>\n\n\n\n<li>Keep stickout at <strong>3\/8&#8243;<\/strong><\/li>\n\n\n\n<li>Weld out of the wind<\/li>\n\n\n\n<li>Clean your metal<\/li>\n\n\n\n<li>Check for leaks<\/li>\n\n\n\n<li>Dial in your voltage &amp; wire feed<\/li>\n<\/ul>\n\n\n\n<p>Do those, and your welds will be strong, clean, and porosity-free.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>If you want, I can also help you diagnose porosity <strong>based on a photo of your weld<\/strong> \u2014 just send it over.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Quick Answer (Straight to the Point) You fix porosity in MIG welds by: Porosity happens when air gets into the [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[4,3],"tags":[],"class_list":["post-40","post","type-post","status-publish","format-standard","hentry","category-mig-welding","category-troubleshooting"],"_links":{"self":[{"href":"https:\/\/beginnerweldertips.com\/index.php?rest_route=\/wp\/v2\/posts\/40","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/beginnerweldertips.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/beginnerweldertips.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/beginnerweldertips.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/beginnerweldertips.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=40"}],"version-history":[{"count":1,"href":"https:\/\/beginnerweldertips.com\/index.php?rest_route=\/wp\/v2\/posts\/40\/revisions"}],"predecessor-version":[{"id":42,"href":"https:\/\/beginnerweldertips.com\/index.php?rest_route=\/wp\/v2\/posts\/40\/revisions\/42"}],"wp:attachment":[{"href":"https:\/\/beginnerweldertips.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=40"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/beginnerweldertips.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=40"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/beginnerweldertips.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=40"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}