Tag Archives: Welding
DIRTY WELDS ARE NEVER STRONG, CLEAN YOUR METAL BEFORE WELDING
The key to any good weld is clean metal, but what is the best way to clean metal before you start welding? Depending on the tools you have and the overall goal of the project there are a few ways to prep your metal to get a nice clean weld every time.
The best welds come from pure clean metal to metal contact, any foreign materials in the welding area can cause welding imperfections. Even brand new metal must be prepped before it can be welded because there is usually a coating put on new metal so it does not rust or oxidize during the shipping process. This is a factor that is often overlooked and will always result in a weak and ugly weld. Be mindful, once you remove this coating the metal is exposed to the elements, if left out unprotected steel will begin to rust, even indoors.
To start, the type of welding you are doing will determine how you prep the metal. Inherently MIG welding steel does not need the metal to be perfectly clean. On the other extreme, TIG welding aluminum requires contaminant free metal to create a strong clean weld. In all of the examples below you can see the difference the dull color of the "new metal" (left) compared to how it looks after it is properly prepped (right).
Angle Grinder with Flap Disc
Using an angle grinder with a flap disc works great to prep steel for MIG or TIG welding. Mild steel does not require the surface to be super clean to get a good weld. In the picture above you can see the left side is brand new untouched steel, it may look clean but it has a thin coating like stated earlier. Once you remove the coating with the flap disc, all it takes is a quick wipe down with Low VOC PRE or Acetone and you will be able to make clean and effective welds. This method works great for heavy welding on chassis parts, this area is always exposed to the elements which will build up contamination over time. Take the time and clean the metal, you'll thank yourself later.
Be careful a flap disc will remove a lot of material so don't use this on thin sheet metal, it may compromise the metals strength.
Similar to using a grinder this method will work great for MIG and TIG welding steel or stainless, but it can be time consuming and does not always remove all of the coatings. Like using a grinder, you must wipe the metal down with Low VOC PRE or Acetone before welding. In the picture above I used 80 Grit sandpaper, it worked well by removing the coating but also left deep scratches that may not look good.
If the metal you will be welding is very rusty and is not suitable to be sanded or removed with a grinder another option to prep the metal is to blast it. After blasting the metal may look clean but it will still need to be wiped down with Low VOC PRE or acetone to remove and chemical contaminants. The abrasive material can sometimes trap pieces of other metals that can cause the metal you are welding to rust or corrode. Never rely on a blaster to prep aluminum for welding, it is very sensitive to contaminants that can get trapped even after wiping it down.
Cleaning for aluminum TIG Welding
When prepping aluminum there is a slightly different process that you will need to be mindful of. Aluminum is very susceptible to contaminants therefore the cleaning process must be done in reverse to produce clean welds.
First you must wipe down the metal with Low VOC PRE or acetone, this will remove any oils or grease on the surface. The next step is to remove any oxides on the surface of the metal. To do this use stainless steel wool or a stainless wire brush on the area to be welded. Make sure that the Steel wool or wire brush is used exclusively for aluminum to avoid contaminants from other metals. Once these tools come in contact with mild steel they can transfer steel bits into the aluminum which will eventually create rust. Finally wipe down the metal with Low VOC PRE or acetone with a clean cloth or rag, from here you are ready to weld.
It doesn't matter what kind of welding you are doing its always important to take the time to clean your metal before welding. Not only will your welds look amazing they will be a lot stronger which is always an added bonus.
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- James R/EW
When you're a beginner at TIG Welding there's a lot of steps to go through to lay a nice weld down. Getting a setting incorrect, or setting something up just a little off can be the difference between a gray mess of bird-turd welds and rainbow colored stacks of dimes. It's no secret TIG welding takes A LOT of practice and even with a perfectly setup machine it won't replace repetition and practice.
Setting up Tungsten stick-out is something that a lot of beginners get confused with. There are some formulas out there to help you determine stick-out, but those don't always work in real world applications. It boils down to setting your torch up to match what you're welding. I have two quick tips that will help get your torch set up (or at least very close) in seconds. Use these methods until you're more confident in your torch setup and it will eliminate one of the stumbling points that beginners struggle with.
1. Quick Stick-out Setup- After grinding you're Tungsten/Electrode you should have a nice taper on the tip. What I like to do is use the taper as my guide for how far the electrode sticks out past the cup. Get yourself close quickly by allowing the entire tapered portion to stick out past the cup. Tighten the torch down so just 1/16" or less past the tapered portion is visible outside of the cup. This setup is a good way to get you in the ballpark and it will work for welding on flat butt joints and many other common weld joints.
2. Use a Spare Tungsten Electrode- When welding a joint together other than a butt weld you may find that the method above may not work and the tip of the Tungsten could be too close or too far from the weld joint. A quick way for a beginner to get the stick-out correct is to lay a piece of the filler rod being used on the weld seam. You can then set your hand and torch where you'll be traveling across the work piece. Then pull your electrode out until it just about touches the filler rod laid in the seam. This will quickly get your electrode set to roughly the right height off of the work surface and with just the right amount of tungsten sticking out from the end of the torch.
These methods aren't super scientific, but they will get you close quickly and easily. Once you get more comfortable you will be able to eyeball the torch setup, but until then you can use these methods for setup and focus on perfecting other portions of the TIG welding process. I hope this helps a few beginners as it definitely helped me out in the beginning! Drop us a comment if you have any suggestions for future tech articles.