Towable Tube Care and Repair: Find Leaks, Patch the Bladder and Know When to Retire It

Inflate the tube with a good pump until it is very firm. Airhead describes a correctly inflated towable as having little or no wrinkling in the cover, which should fit like a second skin; an adult standing on it should not sink in more than about an inch. Tubes are low-pressure, high-volume products, so you do not need a high-pressure pump, but lung power is not enough. If your tube has several chambers with different valves, follow the inflation order in its manual. Check the label for any maker's pressure.

Look over the whole nylon cover in good light:

• Tears, holes or worn-through spots, especially on the bottom
• Seams that are separating or have broken stitching
• A zipper that will not close all the way, or a broken zipper pull
• Faded, chalky or stiff fabric (sun damage weakens it)

A tear in the cover is more serious than it looks. The bladder can push out through the opening ("herniate"), and that bulge is far more likely to burst. Small tears can sometimes be stitched by a canvas or sail repair shop; a cover with large or many tears should be replaced if the maker sells one, or the tube retired.

These are the safety-critical parts:

• Rider handles: pull each one firmly. Stitching should be intact, with no fraying where the strap meets the cover.
• Knuckle guards: present and in place over each handle.
• Tow point: whether it is a quick-connect clip, a tow hook or a sewn-in harness, look for cracks in plastic or metal parts, fraying webbing and torn fabric around the attachment.

Any damage here means the tube is done for the day. A tow point or handle failure at speed is not something to patch with glue.

Airhead says valve leaks are common and often caused by grit or sand stopping the one-way flap inside the valve from closing. Before you hunt for a hole:

• Clean the valve and its cap and blow out any sand with the pump.
• Make sure the cap and any inner plug are fully seated. On two-part screw valves (often called Boston valves), check that both parts are snug.
• Put soapy water on the valve. Bubbles mean the valve itself is leaking.

If the valve still leaks after cleaning, it may need replacing. Some valves are serviceable with parts from the tube maker; others are part of the bladder. Ask the maker before you buy anything. Lost the cap or plug? O'Brien, for one, sells replacement Boston valves through its dealers and customer service, so you don't need a new tube.

Take the bladder out of the cover (usually through the zipper). Then use one of Airhead's two methods:

• Soapy water: inflate the bladder until taut, then sponge on a mix of water and a little dish soap. Watch for growing bubbles.
• Submerge it: let the bladder down to about three-quarters full and push it slowly under water, a section at a time, watching for a line of bubbles.

Circle every leak you find with a permanent marker, then check the whole bladder: there may be more than one hole.

• Pinhole or small puncture in a flat area: usually repairable.
• Small tear in a flat area: repairable with a patch.
• Leak on or right next to a seam: Airhead warns these may not be repairable. A replacement bladder (sold by many tube makers for their models) or a new tube is the usual answer.
• Many leaks, or a bladder that is brittle, cracked or sticky: the material is worn out. Replace the bladder or retire the tube.

Use a kit made for your bladder's material. Airhead notes that PVC inflatables need a different kit than the one it sells for its own bladders, so check the tube's label or manual for the material. Adhesives that do not match the material may never bond properly. Read the kit's instructions before you start; they override general tips like these.

Deflate the bladder completely and lay it flat on a clean, hard surface. Clean the area around the leak with the cleaner your kit names (often rubbing alcohol) and let it dry fully. Patches do not stick to dirt, sunscreen, oil or damp vinyl.

For a pinhole, Airhead says one or two drops of repair adhesive placed right on the hole may be enough.

For a larger hole or tear, follow the patch method:

1. Cut a patch that covers the damage plus about half an inch all around, rounded (no square corners, which peel).
2. Spread a thin layer of adhesive on the patch and on the area around the hole.
3. Wait until the adhesive is tacky; Airhead suggests about two to four minutes, but follow your kit.
4. Lay the patch on and press from the center out to the edges to push out air.
5. Put a flat weight on it so it dries flat.

Patience is the repair. Airhead calls for at least 24 hours of drying before use. Some kits give a different time; use the longer of what your kit and the maker say. Airhead also suggests sealing the patch edges with a little more adhesive once it has dried. Then inflate the bladder and check the patch with soapy water before it goes back in the cover.

Put the bladder back in the cover with the valves lined up with their openings and no twists or folds. Inflate fully. The cover should fit smoothly and evenly. Close the zipper all the way and fit any zipper cover or flap.

• Rinse with fresh water after every use (especially salt water) and clean with mild soap only; SCHEELS warns that harsh chemicals can damage the material.
• Do not leave an inflated tube sitting in the sun on shore. Airhead and Jobe both note the air expands in the heat; let some air out and move it into the shade.
• Let it dry completely, cover and bladder, before storing, to avoid mold and mildew.
• Deflate fully for storage, which also takes stress off the seams, and store it in a cool, dry place out of sunlight and away from sharp objects, chemicals and fumes.
• Mice love a folded tube in a garage or boat locker for the winter. Airhead suggests a lidded, critter-proof plastic tub; a chewed bladder in spring is usually a new bladder.
• Carry the tube rather than dragging it over gravel or concrete.

Replace the tube (or at least the damaged part) when you find:

• A torn or loose tow point, or rider handles with damaged stitching
• A cover with large tears, rotted fabric or failing seams
• Seam leaks, many patches, or a bladder that keeps leaking
• Cracked, brittle or sticky bladder material
• A tube that will not hold firm pressure through a day of riding

A tube is cheap compared with an injury. When in doubt, retire it.