What Are Some Common Mistakes Made With Plasma Cutting?

Well-maintained plasma cutting equipment along with a skilled operator can save a lot of time and money used in the expenses of operating this equipment. This, in turn, will help you make significant profits and make your company flourish.

So to ensure everything runs smoothly, you need to avoid some common mistakes made with plasma cutting. This article focuses on these common mistakes and what you should do to prevent them. Continue reading to find out more.

1) Using consumables past their expected life

Using worn-out consumables past their expected date will not only ruin your metal, but it can also cause the failure of the expensive torch and also increase the downtime.

A skilled and experienced operator can tell when the consumables become worn out by the color of the arc, changes in the height of the torch, and the sound that the torch is producing.

However, the best way to find out the working of consumables is by inspecting them periodically when there is a decrease in the cut quality.

It’s also essential to document the average life of the parts and create guidelines for the expected life of the parts based on material, amperage, and thickness.

Once this is recorded, the operator can then easily check when needed and replace consumables when needed according to it and thus prevent disasters.

2) Changing consumables too soon

In addition to the mistake of using consumables past their date is the mistake of discarding consumables too soon.

To avoid this, the operator should check how the consumable is working and worn. Is the orifice not round anymore? Or are there gouges on the nozzle inside and outside?

If yes, then your consumables will need changing. But if this is not the case, then it can still be used. Check some plasma cutting machine for sale here.

3) Using the wrong consumables for the work

The type of consumable to be used will depend upon the material and thickness of it that needs to be cut, the plasma gas used, the amperage, and other such parameters. The operator’s instruction manual for the plasma system will specify which consumables you need to use.

Using the wrong consumables can reduce the cut quality and shorten the life of parts. Since parts need to be run at the right amperage, it’s best to set it at 95% of the nozzle’s rating to achieve good cut quality and parts life. Because if it is too high, the nozzle life will be affected, and if it is too low, the quality of the cut will be messy.

4) Incorrectly assembling the torch

The torch needs to be assembled carefully to ensure the parts align together and fit together correctly. Proper installation will ensure electrical contact is adequate, and the flow of coolant and gas through the torch is right.

Ensure cleanliness during torch assembly by keeping the consumables on a clean cloth to prevent metal dust or dirt, or grime from contaminating the torch.

Moreover, use O-ring lubricant just enough needed to shine the O-ring. If you use too much, the lubricant can cause metal dust contamination and clog the torch.

This, in turn, will lead to uncontrolled plasma cutting and torch failure. In addition to this, the use of grease is prohibited because it can cause catastrophic arcing as well as burning in the torch.

5) Not checking the gas flow or coolant

It’s important to check the coolant levels, the flow, and pressure of gas in a routine checkup every day. Insufficient flow means the consumables do not have the means to cool off properly, and thus, their life will get reduced.

Insufficient flow can be from clogged filters, worn pumps, low coolant levels, or other such issues that need a prompt checkup. Similarly, adequate plasma gas flow is important.

The gas supply needs to be kept clean to prevent reduced parts life since compressed gas systems are vulnerable to moisture, oil, and contamination from small particles. Moreover, proper gas pressure is also important to ensure proper arc cutting.

An excess of gas pressure will cause fast deterioration of electrodes and a situation known as hard starting, where the torch cannot initiate an arc even though other operation conditions are correct.

6) Stretching of arc

Arc stretching is another mistake you need to avoid. It can either occur at the start or at the end of the cutting. In this, the arc cuts into the nozzle’s side wall, thus ruining it.

When starting on an edge, the nozzle orifice should be directly in the center of the edge. Arc stretching can also occur at the end of the cut.

This happens when the torch with the arc on runs off the plate or when the lead out moves with the kerf of the previously cut piece.

To avoid this mistake, program the lead out and time the arc off signal to ensure efficiency.

7) Cutting too slow or too fast

You will experience problems in the cut quality if you cut too slow or too fast. If the cutting speed is too slow, the cut pieces will have low-speed dross, which is a huge bubbly accumulation of dross at the bottom. 

In addition to this, slow speed can also lead to kerf widening and increased top spatter. On the other hand, too fast speed will cause the arc to lag backward in kerf leading to a narrow kerf, beveled edges, and small hard dross beads at the bottom edge of the piece.

So to prevent all this, a correct cutting speed is imperative. It will generate little to no dross, so you will have clean bottom edges, and your work will be ready for the next stage.

8) Carelessness in terms of regular maintenance

Just like maintaining a car or any other equipment, with proper care and maintenance, consumables can also last you a long time. So it’s important to ensure regular routine maintenance.

Clean the dirt, grime, excess lubricant, or metal dust using a cotton swab with hydrogen peroxide or an electrical contact cleaner.

Moreover, ensure torch threads are clean and keep a look out for contamination or damage in the seating areas.

The bottom line

When it comes to operating equipment and ensuring everything runs smoothly, you need to be careful from the very start to the very end. You must also make sure you know how to use such tools properly.

Small details matter when you are executing plasma cutting, such as ensuring consumables are correctly used, correct parts parameters are used, the speed of cutting is adequate, the torch is correctly assembled, the flow of gas and coolant is sufficient, arc stretching does not occur, and the equipment is regularly maintained. All this can be ensured if you avoid the above-mentioned mistakes.