Plastic Welding: How To

Which materials can be welded?

Only Thermoplastics can be welded. You must weld like for like plastic to achieve a structurally sound bond. CARR Group offers Plastic Weld Rod test packs containing a range of common plastics, these test packs can assist you in identifying which plastic you are working with.

The welding process (rigid plastics)


Prepare the weld surface. Ensure it is clean of dust and dirt so that you can achieve an unobstructed plastic-to-plastic bond. Notch out a “V” groove along the crack or join.


“Tacking” the join or crack together helps to secure the material in place to ensure there is stability and no misalignment of the joins. Run the tip of a tacking nozzle or heated metal item along the join to create an initial bond.


Using a speed welding nozzle or by free hand pendulum welding technique, introduce the plastic weld rod to the weld zone. Ensure equal levels of hot air are directed at the plastic weld rod and the weld surface to ensure they reach “plasticity” at the same time.


When the surface plastic shows signs of slight wetting, move the welding nozzle along the groove while at the same time applying downward pressure on the weld rod to ensure a sound bond.

The below video shows the preparation and welding of rigid plastics

Extrusion Welding

The below video demonstrates extrusion welding and the capabilities it presents. Please talk to our team about the range of tools and equipment we have on offer


Weldy Mini Welder Roof 2 Wedge Welder. Lightweight and easy to operate. Suitable for all pitched roofs, the miniwelder roof2 can be used for all PVC and TPO sub-roof membranes up to 1 mm. As the welding wedge technology manages without air having to be blasted, the sub-roof membrane does not flap about during the welding process. Don’t waste your money on toxic solvent welding agents.

WELDY pitched roof welding with miniwelder roof2

Civil Engineering /Geo Membrane Welding

The WELDY miniwelder geo2 is the perfect professional lightweight welder for various geomembranes. The handy hot wedge welder prevails giant machines in welding quality: handy, simple and good! Perfect welding seam with a compact wedge welder of only 4.0 kg! Yes, only 4 kg.

  • Lightweight and compact
  • Closed loop control of temperature and drive
  • Easy and user friendly
  • Constant speed on vertical and variable road load
  • Wide engineering projects as expressways, reservoirs, waterproofing works
  • Free adjustable speed up to 7.2 m/min
  • Welding temperature up to 480°C
  • Stable performance against ambient temperature and voltage fluctuation

WELDY miniwelder geo2 for geomembranes

Tarpaulin & Banner Welding

Professional welding tools for overlap and seam welds, designed for easy use in the tarpaulins and billboards industries.

WELDY Easy Tarpaulin and Banner Welding