Phospatch is used to coat waffle coolers to prevent contact by molten metal. (Ask for more details.)
The installation can be done at the foundry, on site or installed in the furnace. Outside the furnace, it is easiest to apply the lining with the with the waffle cooler lying on its back, level. It requires short shuttering around the edges, either level with the top of the copper or 40mm above it, at the customer's discretion. If the cooler is upright a sturdy shuttering is required. Build a box frame to fit around the edges. Tilt the cooler backwards and fit the frame. Cut a filling hole in the top and a "riser" hole on the opposite end. Close all gaps and holes. Cover the front. Tie the shuttering securely around the back of the cooler. You can use strapping. If you leave out this step the pressure will push the shuttering off the face. Build a crude funnel around the filling hole, enough to hold 10kg. Do not use oil or grease on the shutterboards.
Weigh out a few batches of 10kg Phospatch powder and 1,8kg liquid binder. Put on latex gloves and mix powder and liquid in plastic bowls. The latex gloves are so you can rip them off and start with clean hands frequently. Phospatch is very sticky and difficult to wash off. Don't wash the plastic bowls, Leave them dirty and break the hard Phospatch off the next day just by bending the bowls. Mix for one minute and dump the mix into the funnel. The material flows slowly into the void. After the first few mixes you can add materials without weighing, judging by consistency. Phospatch is very forgiving. It will work over a wide range of powder to liquid ratios. Add all the material through one filling funnel. The continuity of flow avoids all defects. It is best to have two people mixing, and keep a constant flow of fresh material. Never interrupt the installation. Stop when the riser is full. Now you can prod the material a bit to remove air trapped under the top shuttering. (If you leave the top surface open instead of closed with the two holes, you will need to grind the whole surface flat, as the Phospatch will rise as it sets.) Do not at any point try to vibrate the Phospatch.
Strip the next day or wait until the material gets quite hot, after 2 to 4 hours.
If you follow these instructions you will be amazed at the quality of the installation. There will be no joints, no cracks, no bubbles, no laitance, no bleeding and no sign of any defect or irregularity. Penetration into gaps will be down to 1mm at half metre head and 3mm near the top surface.
Fig 1 Installing Phospatch on water cooled taphole at chambishi in Zambia
Fig 2 Copper cooler at Polokwane Smelter
Fig 3 Framing It
Fig 4 Shuttering completed
Fig 5.Casting Completed
Fig 6. Shuttering stripped
Fig 7. Note Penetration
Fig 8. Detail of casting surface showing the extreme perfection of the structure.
Say goodbye to runouts!!!!!!!
Dave Onderstall 082 808 4757