How to Install a Packing Box on a 35-Foot Bertram

A stuffing box is only used on boats with inboard motors.

A stuffing box is a an assembly used in boat hulls to create a watertight seal. Bertram model boats in the 35-foot model have stuffing boxes which surround the propeller shaft and related components. These boxes are often mistakenly referred to as packing boxes, as the main component is packing material. These boxes must be properly packaged in order to maintain the watertight characteristics. Installation of the packing in the box can be done at home or by an authorized boat servicing center.

Things You'll Need

• Screwdriver
• Pipe wrench
• Spanner wrench
• Degreaser
• Shop cloths
• Measuring tape
• Packing
• Utility knife
• Grease
• Tapping tool

Instructions

1. Remove the cover of the stuffing box using a properly sized screwdriver. Set the screws and cover aside.

2. Loosen the locking nuts on the stuffing box using a pipe wrench and a spanner wrench. Slide the nuts along the shaft to access the box.

3. Remove the bolts from the gland to release the part. Place the bolts to the side. Remove the gland and all of the old packaging from the stuffing box.

4. Pour a small amount of degreaser on a shop cloth. Clean the interior of the stuffing box and all components of the propeller shaft and connected machinery. Wipe away excess degreaser with additional cloths.

5. Inspect the propeller shaft and all connected machinery. Replace any parts that are cracked, leaking or worn.

6. Measure the diameter of the propeller shaft and stuffing box. Subtract the diameter of the propeller from the diameter of the stuffing box. Divide the resulting measurement in half. This is the measurement of the cross-sections you will need to pack your stuffing box.

7. Wrap the packing around the propeller shaft inside of the stuffing box to create four complete loops. The wrap should be snug against the shaft, but the material should not be stretched.

8. Slice along the center of the four loops being careful not to damage the mandrel. Trim off the excess.

9. Lubricate the shaft to allow the rings to slide easily.

10. Slide one ring at a time into the stuffing box so that they wrap around the shaft. Position the cut areas up, to the right, to the left and down for the respective loops. Use a tapping tool to make sure the rings are firmly in position and align well with each other.

11. Replace the gland, or lid, to the stuffing box and secure it into place with the bolts. Tighten the bolts with your fingers until snug.

12. Turn on the pump. Tighten or loosen the bolts until the amount of escaping water is limited. Allow the pump to run for one hour.

13. Reassess the amount of escaping water. Adjust the bolts evenly until the leaking water is approximately 12 drops of water per inch of shaft diameter per minute.

14. Tighten the locking nuts back into place. Replace the cover of the stuffing box and secure it in place.

Tips & Warnings

• If the locking nuts on the stuffing box do not loosen easily, apply a small amount of penetrating oil. Allow the oil to seep between the parts and try removing the nuts again. Avoid oil contact with any other components.

References

• PBase: Re-Packing a Traditional Stuffing Box
• Boat US: Servicing Your Stuffing Box
• Dockside Reports: Leaking Stuffing Boxes