You might be the owner of the most functional and reliable plasma cutter or you’re about to be the proud owner of this machine very soon. Whatever, the cold hard truth is that you may do some common plasma cutting mistakes while using it and avoiding it as much as possible. There is no need to worry because you will find that we have compiled most of the common mistakes of plasma cutting and also the effective solutions.
It is normal that operators, welders, shop foremen, maintenance men, DIY expect that their plasma cutters will perform at a high level and maximally well. But there are some mistakes that are common that you might make while using the plasma cutter. The thing you need as you are about to start using the plasma cutter is to take a look at some common mistakes and their solutions will definitely be helpful to the user. It is better to learn the common mistakes, solve them easily so that you can effectively use the plasma cutter.
Table of Contents
Common Plasma Cutting Problems
Here you can begin to learn the common mistakes and their solutions which you can apply and they are as follows:
1. Neglecting the monitoring of the flow and pressure of the gas and coolant is a common cause of torch and consumables failure. So, it’s important to check it every day. Ensure constant gas pressure to maintain the cutting arc. However, excess gas pressure can cause torch failure to start an arc, even at normal working conditions.
It also creates rapid decaying of the electrode. Compressed air can be affected by oil, moisture and other contamination. It is, thus, important to clean the gas and prevent short torch life.
2. The idea of using worn consumables is a complete mistake for plasma cutting because it will not only ruin a good piece of metal but also can cause torch failure. Moreover, this also causes unnecessary downtime when you are making use of consumables but you can easily avoid these situations.
There are several ways you can easily identify worn consumables. One skilled way you can easily identify this is by the subtle changes in the torch height or the sound or color of the arc. Nonetheless, a very effective way to diagnose the consumables conditions is to examine the cut edge quality of the metal as well as the torch parts when the cut edge begins to worsen.
3. The act of changing out the consumables too frequently is rather an expensive practice as well as a common mistake. It is only wise that you should learn when you need to change the consumables before thinking of changing any consumables.
Some of these conditions need change and should be replaced accordingly:
When any nozzle gets scratched inside or outside or if the hole is worn out of round, it needs to be replaced. By the time you see these signs, you can still reuse the nozzle. By holding it up to a light source, you can observe the aperture and find out easily if it requires changing or not.
Then you need to examine the electrode element pit. Upon observation of dirt or grease in the holes, the arc burns, cracks or excessive wear, the gas swirled need to be changed. The shield is replaced only if you observe signs of physical damage.
4. When you use the wrong consumables and parameters, it leads to short consumable life and reduces cutting quality. You need to take into account the material types and thickness being cut, the plasma gas used, the amperage and other parameters when selecting the consumables.
The proper consumables need to be used with the right height, right arc voltage, pierce delay etc. When the correct amperage setting is used, the best cutting results and consumable life are gotten. A lower amperage setting will give sloppy cutting results, and also at too high amp setting, the nozzle life will decrease.
5. The torch assembling in an incorrect way hampers the electrical contact and flow of gas. Therefore, it is very important to have the correct assembling of the torch. You need to be careful when assembling the torch to align its parts correctly and fit together easily. Maintaining cleanliness is important during torch assembly. You can make use of O-ring lubrication. No other lubrication is needed at all.
6. Moving too fast or too slow can also affect the cut quality. Too slow speed causes wider kerf and excessive top disperse. Once you see sparks shooting on top of the metal, it indicates that you are going too fast and you will also notice a small hard bead of slag and a narrow kerf. The arc would come out at an angle of about 20 degrees in opposition to the direction of the torch path if you cut at a suitable travel speed.
7. Piercing too low is a common error when cutting with the plasma cutter. The amount of the gap between the metal and the tip of the torch affects the cut quality as well as the consumable life. A slight variation in the torch height significantly affects the cut surface. An extremely low piercing height would melt the workpiece, sprinkling it over the front of the shield and nozzle and affecting the cut quality. It can also damage the parts.
8. Another common error is “stretching” the arc, this may happen at the beginning but also at the end if the arc must expand. It could damage the nozzle, cutting off the sidewall of the part. To begin an edge start, align the nozzle opening to center directly over the edge of the metal. To minimize this effect, program the lead out and arc timing.
Ways of Avoiding Common Plasma Cutter Problems
The plasma cutters are high-performance machines that need regular checkups so don’t make it so easy to become overconfident or complacent. It’s important also not to get carried away with using O level lubricant. Using too much will burn out the torch, and whatever you do never apply any lubricant to the torch itself. It never needs any. It is good to note that the lubricant can conduct electricity if splashed on too thickly, attracting counter currents and damaging the torch. These are some good practices that will help you avoid plasma cutter problems
i) Don’t hammer with the torch at any time and on anything whatsoever. This is improper and will lead to the torch failing much quicker.
ii) Always clean the plasma cutter after every single use. This is quite true of the torch itself. The machine parts such as torches and components are expensive to replace and their longevity can be massively enhanced by following these simple rules.
iii) Do not allow any form of collisions of the torch. There are fail-safes and alarms in most modern machines to prevent this from happening, but make sure you double-check as variations in height can still make this to happen. It is quite a swift way of destroying a torch!
iv) Do make sure that the standoff is appropriate to the thickness of the metal. However, the programmable machines will usually configure gas flow automatically, handhelds usually require this to be done manually. Using too much or little gas will cause problems to the equipment and material results.