How's Your Dinghy?

Calculating How Much Sealant to Use With Boats Over 12 Feet:

IMPORTANT!!

Be sure to check out our Getting Started information before beginning any inflatable repair project!

One quart of Inland Marine Sealant® is sufficient to seal small leaks on boats 12 feet long or smaller. On boats larger than 12 feet, there is a formula for calculating how much Sealant to use for each air chamber:

The basic rule is: 1/2 ounce of Sealant will cover 1 square foot of material.

The Formula for finding how many square feet of material there are inside your boat is: (Length of the Boat in feet) x 12 x 2 x (Diameter of the tube in inches) x 3.1416 -:- 576 = Number of ounces of Sealant needed to treat the boat.

This number, divided by the number of air chambers gives the amount of Sealant needed in each air chamber.

EXAMPLE:

A 15-foot boat with 22-inch tubes and three air chambers: 15 x 12 x 2 x 22 x 3.1416 = 24,881.47 square inches total area. 24,881.47 -:- 576 = 43.2 ounces of Sealant will be necessary to treat this boat. Divide 43.2 by 3 air chambers and each chamber will require about 14 ounces. It is recommended that you plan on two applications; use about 8 oz the first time and about 6 oz for the second treatment.

HOW TO:

WITH HELP:

1. Deflate the boat and inject the Sealant in each air chamber as outlined in the standard instructions.
2. Re-inflate the boat to rigidity.
3. Have two people on each end of the boat.
4. Raise the stern to about 45 degrees and hold for about 10 seconds.
5. Lower the stern and raise the bow for 10 seconds.
6. Turn the boat (rotate along its length) about five degrees and raise each end again.
7. Continue rotating the boat 5 degrees at a time and lifting both ends until the boat has been turned completely over.

THE SECOND METHOD IS EASIER AND CAN BE ACCOMPLISHED WITH ONLY ONE PERSON!

1. Place the boat to be treated flat on the ground.
2. Deflate the boat and add the Sealant following the standard instructions.
3. WITH THE BOAT STILL DEFLATED, walk the Sealant around the air chamber, that is, step on the air chamber while it is deflated pressing the top half of the air chamber firmly onto the bottom half.
4. Start at the valves and work your way to the ends until you are sure all the top half of the chamber has contacted the bottom half. (Another alternative to walking the boat is to use a garden type roller to help spread the Sealant.)
5. When you are sure Sealant has made contact with the entire interior of the air chamber, walk it again!
6. Now you’re ready to re-inflate the boat to RIGIDITY.
7. Wait 3 hours, then inflate the boat to full pressure and check for leaks.
8. In the unlikely event that there are still leaks, re-treat the boat using only 1/3 the amount used the first time. Make sure the Sealant gets to the leaking area. Do not allow the Sealant to pool in any one area.

MORE IS NOT BETTER!