Binaural Stand

Constructing a Binaural Hydrophone Stand

Supplies Needed

• Rebar – cut to size
  • 3 leg pieces (2-3 feet long)
  • 2 end pieces (6-8 inches long) hydrophone mounts
  • 2 top pieces for alternate hydrophone mounting (1 foot long)
• 4” diameter pipe (5 foot long)
• Bag of quick set concrete
• 2 foam circles – cut to fit inside ends of pipe
• 2 pieces of 2-foot rope for handles
• Cheap paint brushes
• Ablative Antifouling Paint (Blue) – Copper Technology
• Duct tape

Tools Needed

• Drill with 5/8” bit (bigger than width of rebar)
• Drill with ¼” bit (or width of rope)
• Bucket or wheelbarrow to mix concrete
• Hoe
• Logs to use as supports
• Grinder with cutting disk
• Bucket to pour concrete

Instructions

1. Cut rebar to the lengths needed.

2. Drill holes for rebar (tripod-like legs – one centered on one end, and 2 angled on the other end).

3. Insert rebar into holes at angles appropriate to form support legs.
4. Drill rope holes near ends of pipe legs.

5. Thread rope through holes, knot to form a handle. Cut rope length if needed.

6. Insert foam circle into one of pipe.

7. Add rebar to center of foam.

8. Duct tape the foam and rebar in place on end of pipe.
9. Drill holes for top rebar for alternate hydrophone mount inside of rebar legs – make sure spacing between alternate mount is at least 40 inches apart.
10. Mix concrete to form a pourable consistency using wheelbarrow and hoe.

11. Pour 1/3 of concrete into a bucket (as much as you can easily lift).
12. Support tube standing vertical to support the foam disk.

13. Pour the concrete into the tube. Leave 1 ½ inches (or width of foam) at top of tube.

14. Add foam circle at the top of the concrete, insert rebar in center.
15. Duct tape foam into place.
16. Place tube horizontal standing on legs to let concrete set for at least 24 hours.

17. After concrete sets, paint tube with ablative paint – allow to dry.