Inflatable tenders are one of the greatest inventions of the 20th Century for cruising sailboats. They are small, portable and lightweight when stored, and yet big and stable when inflated. They have huge load carrying capacity and are fast under power.
With all these advantages, you would expect some serious drawbacks. And there are two. First, a good inflatable has a high price tag. Second, they are somewhat delicate and can have a very short life span.
In a combined accountant's language, inflatable dinks have very high amortization rates. A $2,000 tender costs $500 per year if the owner only gets 4 years of service from it. But at 10 years of life, the same dink only costs $200 per year.
The moral of this story is obvious. By maintaining the inflatable to a high standard, the per-year cost of ownership is cut by over 50%. And yet we regularly encounter dinghys utterly ruined within a few years of being new.
Like maintaining good health, most maintenance on an inflatable is preventative. Once a problem has occurred, a major job of restoration and repair ensues. Here are some thoughts:
Never leave an inflatable rolled up tightly for long periods. This is especially important if the storage area is hot, and doubly true if the boat is made of a PVC fabric. Eventually the fabric will weld to itself and destroy the dink. Leave a little air in it and stow it in the main saloon or hung from rafters in the garage.
Never leave an unused boat in the water for long periods. The bottom will grow barnacles or other sea creatures that are nearly impossible to remove without damage to the fabric. Inflexible bottom paint is not easy to keep on fabric bottomed boats if they are rolled up often. Some owners apply grease or other coatings to retard growth, but these can hinder future repairs. It's easier to hoist the boat out of the water when not in use.
Keep the sun off. Again, PVC fabrics deteriorate faster due to UV degradation, but all fabrics wear out faster in sunlight, especially in the tropics. Use a cover if the boat stays blown up on deck, or stow it below when not needed.
Avoid sharp or abrasive objects. Sounds simple enough, but how many inflatables do you see with fenders? One barnacle on the dock piling can make a long tear that is hard to repair. Spearguns, fish hooks and dive knives are common offenders. A few hours rubbing against a rough concrete wall can take years off the boat's life.
Keep it clean. Pull the floor out of the dinghy occasionally to flush abrasive sand, bits of shell and dirt that can wear the boat from the inside out. Spilled chemicals such as gasoline should be attended to immediately. Use mild soap and water to wash away grime. Some stains, especially diesel exhaust on white Hypalon fabric, can not be removed, but other than being unsightly, cause no real harm. Use of silicone or Teflon protectorants will make future repair difficult and should be avoided.
Put sacrificial chafe patches on the fabric where needed. If you carry a second anchor with the dinghy, the top of the bow might benefit from a doubler. This is good practice for patching.
Repair and re-coat wood as soon as required. Many portable boats have plywood transoms or floorboards. I was nearly lost at sea one time when a rotted wooden oar snapped in half at an inopportune moment.
Even with all these preventative measures taken to squeeze as much life as possible from our expensive tender, faults will occur. Mechanical things fail and accidents happen. To solve most mishaps to the tender, you will need three things:
Replacement valves, valve caps and any O-ring seals.
Patches and fabric to match the material and color of the boat.
The proper glue to make repairs.
If you have a leak:
First, always suspect a valve first unless you know of specific damage to the fabric. Valves are the source of most leaks.
To find a leak, use a solution of water rich with dishwashing detergent. A spray bottle works best, although rubbing handfuls of soap over a wet dinghy eventually accomplishes the same thing. Blow the dinghy up hard for this procedure. Go slowly, look for bubbles and mark with a china pencil.
If the hole is merely a pinprick, a product from Sevylor called "Seam Seal" works well. Just a little dab will do you.
If the puncture or tear is larger, or if you've suffered an abrasion that isn't leaking, a patch will be required. Select a standard patch from your repair kit or cut one from your fabric. The edges should extend a minimum of 1" in all directions beyond the damage. Mask off the boat in the shape of the patch to avoid a gluey mess and follow the directions on the glue.