Two Popular Techniques in Plastic Welding: Pendulum Welding & Draw Welding

Understand the Difference Choose the Right Technique for the Job with the BAK RiOn
Two Popular Hand-Welding Techniques You Should Know
When it comes to plastic welding with a hot air tool, professional technicians rely on two main techniques:
Pendulum Welding and Draw Welding.

Both methods use heat to fuse a welding rod into the base material, but they differ in movement, temperature requirements, and the resulting weld appearance, strength, and working speed.

Pendulum Welding The Classic Swing Technique (Swing Movement)
Pendulum Welding is the most universal hand-welding method and works with almost all common thermoplastics, especially PVC, ABS, PP, and PE.
The operator swings the hot air nozzle gently back and forth over the seam while feeding the welding rod by hand.

Quick Steps

• Set temperature based on the material:
  
• PVC 280320°C, PP/PE 300-350°C
  
• Use a slot nozzle for precise heat control
  
• Swing the nozzle evenly across the seam while feeding the rod
  
• Maintain a steady rhythm to avoid burning the material
  

Strengths

• Excellent heat control and precision
  
• Ideal for curves, corners, and confined areas
  
• Compatible with PVC, which cannot tolerate excessive heat
  

Limitations

• Slower than Draw Welding
  
• Requires steady hand control and consistent rhythm
  
  

Draw Welding Continuous Push/Draw Technique (Push / Draw Movement)

Also known as Speed Welding, this method is designed for high-temperature-resistant materials like PP and PE.

The operator attaches a Speed Welding Nozzle to the hot air tool. The welding rod is fed through the nozzle, and the tool is pulled forward in a continuous motion. The rod melts and settles into the seam automatically.

Quick Steps

• Use a Speed Nozzle Ø4Ø5 mm
  
• Set temperature to 300350°C
  
• Feed the welding rod directly through the nozzle
  
• Pull the tool forward steadily for a smooth, solid bead
  

Strengths

• Much faster perfect for long seams or large surfaces
  
• Produces clean, uniform welds with proper speed control
  
• Ideal for industrial applications like pallets, tanks, and trays
  

Limitations

• Not recommended for PVC (temperature and airflow are too high)
  
• Requires proper nozzlerod matching for optimal flow
  
  
  

  Feature	Peudulum welding	Draw welding
  Movement	Swing the hot air nozzle            side-to-side	Feed rod through nozzle and pull backward
  Material Compatibility	PP/PE/PVC/ABS	PE/PP Only*
  Working Speed	Medium	High
  Welding Precision	High control	Smooth & consistent, depends on speed
  Required Accessories	RiOn + Tubular Nozzle	RiOn + Tubular Nozzle + Speed welding nozzle
  Best for	Beginners, repairs, curved seams	Professionals, production work, large surfaces

Why PVC Should NOT Be Draw Welded
Draw Welding uses higher heat and stronger airflow than Pendulum Welding suitable for PP/PE but disastrous for PVC.

PVC has:

• A stiff but brittle molecular structure
  
• Low tolerance to continuous high heat
  
• Chlorine fumes when overheated
  
• Unstable melt viscosity (can over-melt and create weak, porous beads)