Cutting Torch How To Use

Safety Precautions

Working with a cutting torch can be hazardous. It’s essential to follow these precautions to ensure your safety:

Personal Protective Equipment (PPE)

Always wear appropriate PPE when using a cutting torch, including:

Leather Gloves: To protect your hands from heat and sparks
Long Sleeves and Pants: Made of flame-resistant material to prevent burns
Safety Goggles: To protect your eyes from flying metal and sparks
Welding Helmet: With a dark lens to shield your eyes from intense light
Leather Apron: To protect your body from sparks and heat
Safety Shoes: With steel toes to protect your feet from falling objects

Ventilation

Ensure adequate ventilation in the work area to prevent fumes and gases from accumulating. Use a fume extractor or work outdoors if possible.

Fire Safety

Keep a fire extinguisher nearby and be aware of potential fire hazards, such as flammable materials. Clear the area of any debris or obstacles that could catch fire.

Electrical Safety

Use grounded electrical outlets and inspect cables for damage before using the cutting torch. Never operate the torch with bare wires or exposed electrical components.

Work Area

Choose a stable and well-ventilated work area. Make sure there is sufficient space to work safely and avoid contact with flammable objects.

Posture

Maintain good posture while using the cutting torch. Stand upright with your feet shoulder-width apart and your knees slightly bent. Avoid bending over or straining your back.

Gas Handling

Store and handle gases properly in accordance with manufacturer’s instructions. Gas cylinders must be secured upright and protected from physical damage.

Gas	Color
Acetylene	Red
Oxygen	Green

Identifying Torch Components

1. Cutting Tip

The cutting tip is the part of the torch that produces the cutting flame. It is made of copper and has a series of small holes that are used to mix the oxygen and fuel gases. The size of the tip determines the thickness of the metal that can be cut.

2. Oxygen Hose

The oxygen hose is used to supply oxygen to the torch. It is typically made of red rubber and has a diameter of 1/4 inch or 3/8 inch. The length of the hose should be long enough to reach from the oxygen tank to the torch.

Oxygen Hose Specifications
Diameter	1/4 inch or 3/8 inch
Length	Long enough to reach from the oxygen tank to the torch
Material	Red rubber

3. Fuel Gas Hose

The fuel gas hose is used to supply fuel gas to the torch. It is typically made of black rubber and has a diameter of 1/4 inch or 3/8 inch. The length of the hose should be long enough to reach from the fuel gas tank to the torch. The type of fuel gas used will determine the pressure required for cutting.

Fuel Gas Hose Specifications
Diameter	1/4 inch or 3/8 inch
Length	Long enough to reach from the fuel gas tank to the torch
Material	Black rubber

Setting Up the Torch

Before diving into the cutting process, setting up the cutting torch correctly is crucial for ensuring efficient and safe operation.

1. Gather Necessary Equipment

Start by assembling the essential components, including the cutting torch, fuel and oxygen tanks, regulators, and a spark lighter.

2. Connect the Hoses and Regulators

Attach the fuel and oxygen hoses to the respective connections on the cutting torch. Then, connect the other ends of the hoses to the regulators installed on the fuel and oxygen tanks.

3. Adjust the Gas Flow Rates

Precise gas flow rates are essential for optimal torch operation. Adjust the regulators to achieve the desired flow rates specified in the cutting torch’s instructions. The following table provides a general guideline for different cutting applications.

Application	Fuel Flow (ft³/hr)	Oxygen Flow (ft³/hr)
Light Gauge Steel (16 gauge – 1/4″)	15-20	50-60
Medium Gauge Steel (1/4″ – 1″)	20-30	70-90
Heavy Gauge Steel (over 1″)	30-40	90-120

Adjusting Gas Flow

Gas Flow Requirements

Cutting torch operation requires a precise balance of oxygen and fuel gas flow rates. Refer to the cutting torch manufacturer’s specifications for the appropriate flow rates for the specific gases being used.

Adjusting Oxygen Flow

Oxygen flow is critical for achieving an efficient and clean cut. Start by setting the oxygen flow slightly higher than the recommended rate and then adjust it as needed to obtain the desired cut quality. A higher oxygen flow will result in a narrower, cleaner cut, while a lower flow will produce a wider, rougher cut.

Adjusting Fuel Gas Flow

Fuel gas flow also plays a role in cut quality. It should be set according to the type of metal being cut and the desired cut thickness. A higher fuel gas flow rate will result in a hotter flame, which can be beneficial for cutting thicker metals. However, excessive fuel gas flow can lead to flame instability and carbon buildup on the cut surface.

Oxygen-to-Fuel Gas Ratios

The ratio of oxygen-to-fuel gas flow is crucial for maintaining a proper preheat flame and cutting action. A table with optimal oxygen-to-fuel gas ratios for different fuel gases is provided below:

Fuel Gas	Oxygen-to-Fuel Gas Ratio
Acetylene	1.0-1.2
Propane	1.5-1.7
Natural Gas	2.0-2.2

Lighting the Torch

Lighting the cutting torch requires the following steps:

1. **Attach the hoses**. Connect the oxygen hose to the oxygen regulator on the torch and the acetylene hose to the acetylene regulator on the torch.

2. **Adjust the regulators**. Open the oxygen valve slightly and adjust the regulator to the desired pressure for cutting. Then, open the acetylene valve slightly and adjust the regulator to the desired pressure for cutting.

3. **Turn on the torch**. Open the torch valve to allow a small amount of oxygen to flow through the torch. Then, open the acetylene valve slightly to start the flow of acetylene.

4. **Ignite the acetylene**. Hold a spark lighter or striker next to the tip of the torch and ignite the acetylene.

5. **Adjust the flame**. Once the acetylene is ignited, adjust the oxygen and acetylene valves to create a neutral flame. A neutral flame has an inner cone that is slightly bluish and an outer cone that is slightly oxidizing. The flame should be about 1/4 inch long.

Oxygen Pressure	Acetylene Pressure	Flame Appearance
Low	Low	Short, yellow flame
High	Low	Long, oxidizing flame
Low	High	Short, carburizing flame
High	High	Neutral flame

Proper Cutting Techniques

To achieve optimal results when using a cutting torch, it’s crucial to adhere to proper cutting techniques. These techniques involve a combination of precision, skill, and safety measures. Mastering these techniques will enable you to execute clean and precise cuts while minimizing sparks and slag accumulation.

Torch Setup

Ensure that the cutting torch is properly set up before initiating the cut. Adjust the gas pressures and flame settings to suit the specific metal you’ll be cutting. Incorrect setup can lead to poor cut quality or potential safety hazards.

Starting the Cut

Begin the cut by holding the torch perpendicular to the metal’s surface. Engage the cutting oxygen lever while simultaneously moving the torch forward at a steady pace. As the metal starts to melt, it will form a kerf (the cut’s width). Aim to maintain a kerf width of approximately 1/16 to 1/8 inch for most metals.

Maintaining the Cut

Once the initial cut is established, consistently move the torch forward at a speed that allows the cut to proceed smoothly. Adjust the cutting oxygen flow as needed to control the cut’s speed and quality. Proper speed and gas adjustment will minimize the formation of slag and produce a clean, slag-free cut.

Piercing the Metal

To pierce a hole in the metal, hold the torch stationary over the desired piercing point. Engage the cutting oxygen lever and slowly lower the torch until it touches the metal’s surface. Once the metal starts to melt, gradually increase the downward pressure and move the torch in a circular motion until the hole is pierced.

Cutting Curves and Bevels

To cut curves and bevels, adjust the angle of the torch to the metal’s surface. For curves, tilt the torch inward or outward to follow the desired path. For bevels, hold the torch at an angle to create a beveled edge on the metal.

Controlling Slag

Slag is the molten metal oxide that forms during the cutting process. To minimize slag accumulation, adjust the cutting oxygen flow and the angle of the torch. A proper cutting speed and a slight forward tilt of the torch will help prevent excessive slag formation. Use a chipping hammer or wire brush to remove any slag that does accumulate.

Metal	Cutting Oxygen Pressure (psi)	Preheat Oxygen Flow (cfh)
Mild Steel	25-30	2-4
Stainless Steel	40-50	4-6
Aluminum	15-20	4-6

Troubleshooting Common Issues

1. Poor Cutting Performance

Inspect the torch tip for wear or damage. Replace if necessary. Ensure adequate gas pressure and flow rates. Check the cutting oxygen flow rate, as an incorrect rate can result in poor cutting performance.

2. Excessive Heat Buildup

Reduce the cutting speed or increase the standoff distance. Adjust the oxygen flow rate to avoid overheating. Inspect the cutting tip for any obstructions or blockages. Ensure that the torch and nozzle are aligned correctly.

3. Backfire

Check the gas pressures and flow rates. Ensure the preheat flames are adjusted correctly and that the cutting oxygen flow starts before the cutting oxygen valve is opened.

4. Oxide Formation on the Cut Surface

Increase the cutting speed or decrease the standoff distance. Adjust the oxygen flow rate to achieve a clean cut. Use a higher purity oxygen for improved cut quality.

5. Slag Accumulation

Increase the gas flow rates to clear away slag. Adjust the cutting speed and standoff distance to reduce slag buildup. Use a nozzle with a larger diameter.

6. Deviations in the Cut Line

Check for any obstructions in the cutting path. Ensure the torch is held steady and at the correct angle. Adjust the cutting speed and gas flow rates to maintain a straight cut line.

7. Cutting Torches for Various Materials

Different materials require specific cutting torches and gas mixtures. The following table provides a general guide:

Material	Cutting Torch	Fuel Gas	Oxygen
Mild Steel	Oxy-fuel torch	Acetylene	Yes
Stainless Steel	Plasma cutter	Argon	Yes
Aluminum	Laser cutter	Nitrogen	No
Glass	Waterjet cutter	Water	No

Cooling and Handling the Torch

Once you have finished cutting, it is important to cool the torch properly to prevent damage. To do this, simply turn off the oxygen and fuel gases and allow the torch to cool down naturally. Do not quench the torch in water, as this can cause thermal shock and damage the torch.

When handling the torch, always be sure to wear appropriate safety gear, including gloves, safety glasses, and a welding apron. The torch can become hot during use, so it is important to avoid touching the torch with your bare hands.

Moving the Torch

When moving the torch, always be sure to hold it by the handle and keep the torch tip pointed away from you. Never carry the torch by the hose, as this can damage the hose and cause the torch to fall.

Storing the Torch

When storing the torch, always be sure to disconnect the torch from the gas supply and allow the torch to cool down completely. Store the torch in a dry, well-ventilated area away from flammable materials.

Troubleshooting

If you experience any problems with the torch, such as a clogged tip or a leaking hose, be sure to consult the manufacturer’s instructions for troubleshooting.

Maintenance

The torch should be regularly inspected and maintained to ensure proper operation. Regular maintenance includes cleaning the torch tip, checking the hoses for leaks, and replacing the spark plug as needed.

Safety Precautions

Always follow the safety precautions when using the cutting torch. These precautions include:


Never use the torch in a confined space.	Always wear appropriate safety gear.
Never touch the torch with your bare hands.	Never carry the torch by the hose.
Always disconnect the torch from the gas supply when not in use.	Always allow the torch to cool down completely before storing.
Always consult the manufacturer’s instructions for troubleshooting and maintenance.	Always follow the safety precautions when using the cutting torch.

Post-Cutting Clean-Up

Once you’ve completed your cutting, there are a few steps you should take to clean up and ensure safety.

1. Shut Off the Fuel Supply

Turn off the fuel supply to the cutting torch and disconnect the fuel tank.

2. Allow the Cutting Torch to Cool

Let the cutting torch cool completely before handling it.

3. Remove the Cutting Tip

Once the torch is cool, you can remove the cutting tip using a spanner or wrench.

4. Clean the Cutting Tip

Use a wire brush or a compressed air gun to clean any slag or metal deposits from the cutting tip.

5. Inspect the Cutting Torch

Inspect the cutting torch for any damage, such as leaks or cracks. If you find any damage, repair it or replace the torch.

6. Clean the Work Area

Sweep up any metal chips or slag from the work area and discard them properly.

7. Ventilate the Area

Ensure adequate ventilation to remove any harmful fumes created during the cutting process.

8. Inspect the Cut Surface

Carefully examine the cut surface for any imperfections or defects. If you find any, grind or smooth them out.

9. Apply a Protective Coating (Optional)

To prevent corrosion or oxidation, you can apply a protective coating, such as paint or a rust-resistant spray, to the cut surface. Choose a coating that is suitable for the material you’ve cut and the intended use of the piece.

Tip: Follow the manufacturer’s instructions for proper application and drying time.

Material	Suitable Protective Coating
Mild Steel	Galvanized paint, Oil-based paint, Epoxy paint
Stainless Steel	Stainless steel cleaner, Passivation solution
Aluminum	Aluminum cleaner, Aluminum anodizing solution

Maintenance and Storage

Daily Maintenance

Proper maintenance is essential to ensure a long lifespan and optimal performance for cutting torches. Perform the following daily maintenance tasks:

Clean the cutting tip with a wire brush to remove any spatter or debris.
Inspect the hoses and cables for any damage or leaks.
Check the oxygen and fuel pressure gauges to ensure they are within the recommended operating range.
Tighten any loose connections.
Store the torch in a dry, protected area when not in use.

Periodic Maintenance

In addition to daily maintenance, periodic maintenance is also necessary to keep the torch in good working order:

Lubricate the moving parts with a high-quality lubricant.
Replace the cutting tip if it becomes damaged or worn.
Have the torch inspected by a qualified technician annually.

Monthly Maintenance

To keep your cutting torch in peak condition, perform monthly maintenance, which includes the following steps:

Check the hoses and cables for any signs of wear or damage.
Inspect the oxygen and fuel regulators to ensure proper operation.
Lubricate the moving parts.
Clean the torch body and accessories.
Store the torch in a dry, protected area.

Storage

When storing the cutting torch, follow these guidelines to prevent damage and ensure longevity:

Store the torch in a dry, protected area.
Release the pressure from the hoses and cables.
Cover the torch tip to prevent debris from entering.
Store the torch in a vertical position to prevent damage.

Troubleshooting

If you experience any issues with your cutting torch, refer to the troubleshooting table below:

Problem	Possible Cause	Solution
No flame	Empty fuel tank	Refill fuel tank
Weak flame	Clogged cutting tip	Clean cutting tip with a wire brush
Backfire	Dirty or damaged oxygen regulator	Inspect and clean or replace oxygen regulator
Cutting too slow	Worn cutting tip	Replace cutting tip
Cutting too fast	Damaged cutting tip	Replace cutting tip