Eastwood Auto Restoration Blog - Free How-to Automotive Tech Advice for Everything DIY Automotive
Plasma cutting seems easy right? Pull the trigger, make some sparks, cut some metal, easy as pie! Well it can be quite simple, but there are a few things that can cause your plasma to underperform. Below we cover 5 tips to allow you to cut any metal with ease.
1. Clean your ground location- Some of the modern plasma cutters like our Versa Cut Plasma Cutter have a "high frequency start" that allows the plasma arc to blast through rust, paint, and years of grime to cut metal without the need to clean the area you are cutting. This is great for those who hate cleaning metal; but one thing that people often forget is that they need a clean, solid ground to help create a strong arc to easily cut through metal. With a subpar ground you will find that your arc is unstable and will often result in inconsistent cuts. Take the extra 2 minutes to find a good ground location, or grind yourself a clean clamping area. It makes a world of difference!
2. Keep your torch "Slag-Free"- When cutting with a plasma, you have molten metal splattering and slag goes flying; especially when cutting with the torch below the work surface. The slag can inadvertently make its way onto your torch electrode or nozzle. The build up of slag on the business-end of your torch can create an unstable arc and block airflow out of the nozzle. That buildup leads to poor cutting ability even on the most expensive machines. We suggest that you check the end of your torch after each cut to make sure there isn't a build up of slag that can decrease the performance of your plasma cutter.
3. Dry Air is Friendly Air- Plasma cutters need a constant flow of clean, dry air to allow it to "punch" through the metal when cutting. This is another reason we can't stress enough how important it is to make sure your compressor has an adequate dryer and water separator system installed. For that reason we integrated a "last chance" filter in our Versa Cut plasma to make sure clean, dry air reaches the plasma torch. When you introduce dirty or moisture-rich air into the plasma arc you will notice that it will be difficult to get a stable arc going as the moisture in the air coming out of the torch will cause the arc to wander. You NEED clean, dry air to create a stable, focused arc!
4. Avoid extension cords- We put a 20' torch lead and a 10' ground lead on our Versa Cut for a reason; you need to keep the machine as close to the power source as possible. The same as using a welder, the longer and skinnier the extension cord, the more it drops the voltage your machine is receiving. This means you could be "maxing out" your machine cutting something that should only require 3/4 power because the drop in voltage at the machine is so low by the time it goes through that 20 foot extension cord. We suggest (especially on the 110V setting) to keep your plasma plugged directly into an outlet. If you do need to use an extension cord, get a dedicated heavy gauge extension cord that will have the least power drop possible. By heeding this warning you can get the most performance out of your plasma. Remember, move the work surface or torch and ground, not the entire machine!
5. More Air= More Punch- Like the amperage adjustment, we have an adjustment for air pressure along with a built-in pressure gauge. You need to make sure that you have adequate air pressure going to the torch to allow the plasma arc to properly "punch" through the metal. "Too much" air isn't as much of an issue as "too little" air, although you do want to dial the air down a bit with thinner metal to reduce the amount of slag and sparks from flying across the room.
Hopefully by following these 5 tips you can streamline your plasma cutting jobs, and keep your machine function properly.
When learning to MIG weld, one of the biggest things you can do is to listen to the sounds your welder makes when welding; and also knowing what the error is when looking at a weld. Once you understand what to look and listen for, you will notice your welds improving dramatically.
A properly adjusted MIG welder should sound like it is frying up bacon when laying a bead. You want a nice sizzle with little "pops and spits". The final weld should be relatively flat and even throughout. Above you can see some examples of MIG welds. The first weld has our MIG 175 settings dialed in pretty good. Notice how the bead isn't protruding from the work surface too much, and the bead is fairly uniform in width. The backside of the work piece will show a nice outline of where the weld penetrated properly into the metal.
On the second bead we turned the wire speed up way too high. You can instantly tell the difference in sound and look of the bead. You can also feel it in the MIG gun when welding. The problem here is that the welding wire is coming out too fast for the surface you are welding on and the heat settings you are using. The wire is hitting the surface and not melting into the metal fully. You will feel the wire pushing back on the MIG gun because of this, and you will hear a lot of random popping from the welder. Lastly, you can see in the picture that as we moved along the welder just made individual "globs" but no puddle was formed. With this weld you won't see an outline of the weld on the backside of the metal as it hasn't penetrated into the metal. This is very bad, and is a weak, dangerous weld.
The third bead we did quite the opposite, we turned the wire speed far too low. When you do this you will notice a pronounced "hissing" when welding. This will sound like you have a gas leak. You will also notice the wire burning before it even gets to the surface and the inability to move the puddle. You can see in this example the puddle started, but as soon as you move a little bit, you lose the puddle and the welding wire isn't coming out fast enough to keep up and add to the puddle. Because of this you can see the arc was still present, but the puddle didn't start again until we stopped moving and let the puddle form. This is also a weak, unsafe weld, and should not be used.
The fourth example is a common mistake when you first begin welding. In this bead we left the shielding gas bottle turned off, and attempted to run a bead without the aid of shielding gas. When this happens, there will be an extreme amount of popping and hissing, as well as an excessive amount of sparks and slag flying from the work area. The shielding gas cleans the weld puddle and keeps contaminates from entering the weld and making it weak. Here you can see the weld is very porous and much darker in color. Keep this in mind when welding. If you see a weld like this, make sure you check that your gas bottle is turned on, the tank output pressure isn't too low, and the tank isn't out of gas. DO NOT attempt to use anything you have welded without shielding gas, all of those pores are imperfections that will make the weld weak.
Now go out in the shop, set up your welder, turn the music down, and listen to what your MIG has to say. It has a lot to tell you!