Appendices To Manual > L - Filter Construction Checklist

FILTER CONSTRUCTION CHECKLIST 1. Cut and bend the copper (or plastic) tubing to size; then cover the end with tape. 2. Clean, oil, and then assemble the mold. 3. Insert and hand tighten all bolts; then tighten all bolts with a wrench. 4. Place the tubing in the mold, position the nose plate with the tubing sticking through, tighten the set screw, clamp the end of the pipe to hold it, and plug the standpipe outlet.

5. Tape the tubing onto the interior mold to hold it in place. 6. Use a level and wooden shims to make the mold level.

7. Measure and mix 10 L of Portland cement, 20 L of sieved sand, and 21 L of sieved ½” gravel, adding water gradually while mixing to make a fairly stiff mix (about 7 litres of water). Quantities may vary depend on the exact size of the mold and the moisture content of the sand.

8. Shovel concrete into the mold, a few shovel-fulls at a time. 9. Use large rod as a tamper and hit the outside of the mold with the mallet in an upward pattern. 10. As you fill the last of the mold, check the tubing to be sure it has not moved. 11. Jab your trowel 4” into the concrete, all around the inner mold, to ensure the last bit of concrete mixes.

12. Smooth away the excess concrete with a flat board and then trowel it, to leave a flat surface. 13. Wait 18 - 24 hours, no longer. 14. Remove the nose plate. 15. Turn the mold upside down, using a tire or a sack of grain to support the mold. 16. Remove the bolts on top of the mold. Do not loosen any of the side bolts yet. 17. Hit the top of the mold with a mallet to loosen the bond with the concrete. 18. Place the puller assembly on top of the mold. 19. Tighten the centre bolt (by turning it clockwise) until it is well threaded into the nut on the mold. 20. Tighten the nut above the puller by turning it clockwise until the interior mold releases. 21. Remove the puller assembly; then carefully remove the interior mold and store it safely. 22. Remove the remaining bolts and the 3-sided panel; then remove the front (nose) panel. 23. Clean and oil the mold.

24. Remove excess tape that covers the tubing opening in the interior of the filter. 25. Check both ends of the tubing to ensure they have not been plugged by concrete. 26. If the tubing extends more than ½” out of the concrete nose, cut it to ½” or less in length. 27. Fill the filter with water. The flow rate should be about 1L / 25s. Check for cracks in the filter.

28. Fill the filter with water for 5-7 days while it cures. Do not transport the filter during that time. 29. Before installation, scrub the inside of the filter out with a broom or scrub brush, soap and water.