Welding Talk - Reducing Spatter in MIG Welding
The difference between spatter and splatter is real and important. The New Oxford Dictionary of English defines spatter as to ‘cover with drops or spots of something’. Splatter, on the other hand, is ‘to splash with a sticky or viscous liquid’. Whether you suffer from ‘spatter’ or ‘splatter’ when you MIG weld, it can (sometimes literally) be a pain. This week in Welding Talk we talk about Reducing MIG Spatter.
First off, why are we focusing on spatter with MIG welding? Well, as a general rule, the TIG process is a lot cleaner – that’s one of its greatest advantages. For all practical purposes, you don’t get spatter with TIG welding, so let’s look at MIG spatter.
What weld spatter is
Thinking about MIG welding, let’s start by clarifying what spatter is. And how drops and spots of molten metal come to fly around your welding bench, into the creases of your clothes, and even, if you aren’t wearing suitable PPE, down your neck.
It happens, says our sales adviser Mike Gadsby, as he recalls a particularly uncomfortable incident. ‘It was really painful; I felt that spatter all the way down my back, into my trousers and down to my feet. Like arc eye it’s something you don’t forget. As with arc eye, if you’re smart you do everything you can to make sure it doesn’t happen twice. Ouch!’
What causes MIG spatter?
MIG welding spatter happens when contaminants such as rust, oil, old paint or even water find their way into the weld zone. More often than not in our experience, it’s down to inadequate material preparation, the wrong MIG wire choice, wire-feed issues or poor selection of gas and gas flow-rate. Using gasless MIG also means more spatter. It’s typically due to the flux in
Material prep and machine set-up matter
As ever, thorough material preparation makes a difference, as does careful machine set-up and careful attention to the balance between wire diameter and your welding amperage. Poor MIG dip transfer technique can also cause problems if too much wire is introduced into the weld pool and some of the wire bounces off…
Allow too much wire to get into the weld pool, the wrong wire or just ‘out of position’ wire and you’re setting the scene for troublesome spatter. Just as correct selection of filler rods matters for MMA welding, so correctly matching MIG wire to the parent metal is vital. Excessive weld spatter becomes a problem when molten weld metal leaps from the weld pool and lands on other parts of the work-piece, jigs, your welding bench or the far corners of your workshop.
The ‘Tigger’ of welding?
Make no mistake; MIG spatter can have the energy of Walt Disney’s Tigger as it flies around. It’s a serious fire risk – we know of cases where welders have set fire to barns while welding cars. It happens, and MIG spatter can easily fly several metres from the weld pool. That’s why you should always check the welding area 30 minutes after work has finished. Many welding shops won’t allow welding to take place within half an hour of the premises closing for the evening – and for good safety reasons too.
Prevention and cure
Spatter does more than make a mess. It takes time and effort to clean off with a cold chisel and that extra work takes time as well as bringing the risk of damage to the work-piece. For amateur welders, cleaning and rework is annoying; for professionals it’s another cost.
Our team has plenty of weld spatter stories, and not just the ones where stray molten metal met a welder's skin. They’ve seen vehicle windscreens damaged and windscreen wipers ruined because of spatter. Too often, welding jobs have been rejected when spatter got into the bores of mechanical parts or ruined bolt threads. You’ll never avoid some spatter, but by keeping a tidy work area and covering up things that you can’t move, you can minimise the problem. A few strips of aluminium tape can easily protect those threads and it only takes seconds to put fireproof sheeting over a vehicle windscreen.
PPE and fire equipment
It goes without saying (but we will anyway) that, as well as welders wearing suitable PPE, every welding environment should have suitable fire extinguishers and a fire blanket in case anything ignites. Of course, prevention is better than cure, which brings us back to material prep, correct set-up, the right consumables choices and readily available anti-spatter sprays, which may be ceramic or vegetable oil based.
Let’s talk spatter (or splatter)
With decades’ experience in welding, there’s not much that our team hasn’t seen. And as you read earlier, we've often learned lessons about spatter the painful way!
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