How to Modify A
Power Tex Spray Nozzle

The Power Tex Hopper Gun is sold with a set of 5mm and 7mm spray nozzles of which we only use the 7mm to spray face coat mixes. We bore the 5mm to 5/16″ and it to spray fiber reinforced concrete mixes. This technique is ideal for spraying CHENG’s D-FRC Casting Mix or Surecrete’s Xtreme Precast Mix. The fine PVA fibers in both of these mixes will pass through the larger nozzle with no problems but mixes containing Alkali Resistant Class Fiber shouldn’t be attempted. They will plug the nozzle.

Step 1 – Nozzle Comparison and Setup

  • The nozzle on the left is a 5mm nozzle before modification and the one on the right has been bored to a 5/16″ opening which allows fiber reinforced mixes to pass through it.
  • The photo of the backside shows how the right nozzle should look after the nozzle is modified with a taper bit.
  • Hold the nozzle in a vice or with clamps while working on it.

Step 2 – Drill 5/16″ Hole

  • Enlarge the hole by drilling from the backside with the 5/16″ bit first.
  • Use cutting oil while drilling to keep the bit and nozzle cool.
  • Drill a 5/16″ hole completely through the nozzle.

Step 3 – Taper the Back Side

  • Enlarge the backside taper with an Irwin number 9 Unibit or similar.
  • Be careful and only taper the backside to a minimum wall thickness of 1/16″ . Drilling  too deep will weaken the wall thickness and start to remove threads.

Step 4 – Modification Complete

Modifying the Power Tex MK3 Spray Gun Nozzle - Step 4 | Concrete Exchange
  • The nozzle has been drilled and tapered to allow CHENG D-FRC Casting Mix or Surecrete Xtreme Precast Mix to spray freely through the nozzle.
  • After drilling and tapering the modified nozzle can be attached to the Power Tex Mk3 Spray Gun.