Draw/Speed Welding

​The use of speed welding tips on our hot air tools increases both the concentration of hot air and the amount of profile welding material that can be deposited in one pass. Generally, welding with this method results in welding speeds up to 15 times faster than pendulum welding. The welding process itself, as shown to the right, is the same as the pendulum method with the exception that the speed welding nozzle is used to guide the rod onto the welding joint.

Starting the Weld: Insert the welding rod through the nozzle feeder until approx. 5 mm protrudes on the underside. Hold the tool so that the speed welding nozzle sole runs along the groove. The protruding rod must be held beyond the start of the “ V “ groove so that heat is directed on the start point for welding. When the surface plastic shows signs of slight “ Wetting” move the welding nozzle along the groove.

Continuing the Weld: Once the weld has been properly started, the hot air blower is brought to a 45 degree angle and the rod will feed automatically without further help. With PVC pushing of the welding rod through the speed welding nozzle may be necessary. Wherever possible the weld should be completed in one continuous run along the groove.

Finishing the Weld: To stop welding, bring the speed welding nozzle back past the 90 degree angle and cut off the rod with the end of the shoe.

Corner Welds: Always start a weld in a corner, do not weld to a corner. Trim welding rods to a pencil point to allow for staking of start of welds in the corner. Layer each pencil or arrow rod’s end for each corner groove.

Welding seam preparation

Welding area & weld rod must be:

• dry, clean, free of oil & grease
• free of notches
• free of oxidation (to achieve this the joining area is scraped clean just before welding

Note on compressed air usage:

• If using compressed air with your hot air tool, ensure that there is a pressure reducer and an oil and water filter before turning the air on

Welding parameters

Material	Welding force (3mm rod)	Welding force (4mm rod)	Hot air temp.	Air flo
PE-HD	10 - 16 N	25-35 N	300 - 320°C	40 - 50 l/min
PP	10 - 16 N	25 - 35 N	305 - 315°C	​40 - 50 l/min
PVC-U	8 - 12 N	15 - 25 N	330 - 350°C	40 - 50 l/min
PVC-C	15 - 20 N	20 - 25 N	340 - 360°C	40 - 50 l/min
PVC-P	4 - 8 N	7 - 12 N	300 - 370°C	40 - 50 l/min
PMMA	12 - 16 N	20 - 30 N	320 - 370°C	40 - 60 l/min
PVDF	12 - 17 N	25 - 35 N	365 - 385°C	​45 - 55 l/min