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Solved problems · Dinghy · Crew answer

Why is my inflatable dinghy losing air?

Slow leaks in inflatables most often come from the valves, then seams and small punctures. Soapy water shows where. Here's how to find it and choose the right repair.

Symptom

One or more tubes get soft overnight or over a few days, or the floor or keel loses pressure.

Likely cause

Inflation valves leak when their seals are dirty or the valve body has worked loose. Seams can open with age and heat, and small punctures come from sharp objects or chafe. Temperature changes also make pressure drop overnight without any leak, so compare at the same temperature.

Stop now if

A tube deflates fast while the dinghy is in use. Get everyone to shore or back aboard the boat, keep weight on the inflated tubes, and wear lifejackets.

The fix, in short

  1. Rule out temperature. Pump up in the morning and check again the next morning, not in the cool evening. A small drop with a temperature change is normal.

  2. Check the valves first. With the tube inflated, brush soapy water over each valve and watch for bubbles. Tighten a loose valve body with the correct valve wrench, or remove it and clean the seal as the maker describes.

  3. Soap the seams and tubes. Inflate one chamber at a time and work over seams, patches and fittings with soapy water. Mark any bubbling spot.

  4. Use the right glue. SAIL notes you need to know whether the boat is PVC or Hypalon, because each needs its own repair adhesive. Follow the maker's repair kit instructions for cleaning, gluing and curing.

  5. Avoid the wrong products. Don't use general marine sealants on inflatable fabric, and avoid slick protectants that stop future patches from sticking.

  6. Get seams professionally repaired. Long seam failures and big tears are best left to an inflatable repair shop.

Written by Sailor Cruiser crew. General guidance, not an inspection of your boat.

Equipment involved

  • Dinghy: Inflatable dinghy tubes, valves, seams, floor and keel chamber

Related guides

Sources

Background reading we checked while writing this answer. The wording above is our own.

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