Heat Weld Nozzles and Rod: Which Tip for Which Job

The nozzle controls how heat reaches the weld rod and the groove. Match the speed nozzle to the rod size, use the rod the flooring maker specifies, and set the temperature on scrap before you touch the floor.

Types of nozzles

A welding kit usually includes more than one tip, and each has a job.

• Speed welding nozzle: feeds the rod through a tube and preheats the groove and rod together. It's the tip you run seams with. The Leister 106.990 is a speed nozzle for 4 mm round rod^[1], and the Leister EASYFLOOR kit includes a speed nozzle for 5 mm round rod.^[5]
• Tacking nozzle: a small tip for tacking materials in place before welding.^[1]
• Pencil tip: a narrow open tip for hand-welding corners and short runs where a speed nozzle won't fit.
• Adapters: let one brand's tips fit another brand's gun, such as a Triac adapter.

Match the nozzle to the rod and floor

The flooring maker's instructions set the rod and tip. Find your floor below, then confirm against the sheet in the box.

Linoleum and vinyl rod are not interchangeable. Use the maker's rod for the product line, and the matching tip size.

Setting the heat

Gun settings vary with the gun, voltage, extension cord and room temperature, so the number on the dial is only a starting point.

1. Install the right speed nozzle for your rod and let the gun reach temperature.
2. Weld a test seam on scrap of the same flooring.
3. Check it against the signs of a good weld: the rod reaches the bottom of the groove and a small bead forms on each side.^[2]
4. Scorched or discolored rod means too hot or too slow. Rod sitting on top of the groove means too cool or too fast.
5. Adjust and retest before welding the floor.

The full process is in Heat welding sheet vinyl, step by step.

Care of nozzles

A dirty or bent nozzle changes how heat reaches the rod.

• Clean melted rod off the tip while it's warm, with a brass brush. Steel tools scratch the nozzle.
• Don't bend a speed nozzle's rod tube; it should feed straight.
• Let the gun cool on its stand before swapping tips, and use pliers or a glove.

Common mistakes

Most weld problems blamed on the gun are really nozzle or rod mismatches.

• A 5 mm speed nozzle with 4 mm rod. The rod wanders and the weld is uneven.
• Vinyl rod on linoleum, or the reverse. They don't fuse properly.
• Welding too soon. Wait about 24 hours after installation so the adhesive has set.^[2]

Nozzles we carry

These are the most common speed and specialty tips we stock.

• High-speed tips: 5 mm and 4 mm
• Curved speed nozzles: 5 mm and 4 mm
• Turbo 2-L 4/5 mm Tip for Linoleum and Turbo 3 Triac Adapter
• All nozzles and adapters

References

1. Leister: Speed welding nozzles
2. Forbo: Heat welding vinyl products
3. Forbo: Heat welding Marmoleum and linoleum
4. AHF/Armstrong: Commercial sheet installation instructions
5. Leister: Triac ST EASYFLOOR kit

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