For all of the benefits that come with owning an inflatable kayak, there is one significant drawback. Eventually, your inflatable kayak will leak. While it might seem like the end of the world at the time, it isn’t. Keep reading to learn how to find and fix an air leak in an inflatable kayak.
The broad steps in the process of finding and fixing an air leak are neither difficult to remember nor onerous to master. First, locate the leak by listening or by using a bubbling detergent. Next, cut out a patch that is properly-sized for the hole and is the same material as the kayak. Then, apply an adhesive (that is compatible with the kayak material) to the kayak as well as the patch. Finally, affix the patch with pressure, to the kayak and allow it sufficient time to dry and cure.
Table of Contents
How do you get an air leak in the first place (and how do you avoid them in the future?)
Inflatable kayaks are constructed to take a beating. For the most part, their design allows them to withstand the typical obstacles that a boat meets during a day of paddling. In fact, some inflatable boats are actually designed to be operated in extreme conditions. All this to say that you don’t need to wear white gloves and speak in hushed tones for fear of puncturing your boat.
Nevertheless, a little forethought and good judgement can go a long way towards keeping your kayak leak-free.
Paddling over sharp hazards can put a hole in your inflatable kayak. No kidding, right? Quite simply, it is important to be acutely aware of your surroundings – particularly the surroundings under your kayak.
Are you paddling on a river with fallen tree debris? How about a northern lake with a rocky shoreline? Or perhaps a coastal beach with pockets of coral?
It is best to understand the unique characteristics of the watery landscape waiting for you and your boat before you venture out. Do your best to avoid shallows when if their is risk of tree branches, rocks or coral. At a minimum, plan your navigation route such that your kayak has a fighting chance of making it through the hazards unscathed.
Dragging your inflatable kayak over rough ground can create leaks. Sometimes this rough ground is characterized by sand and dirt. Other times it is littered with roots, twigs and rocks. That’s if you’re lucky. It’s not uncommon to find broken glass, bottle caps, crushed soda cans and all manner of other man-made debris as well.
So, not only is it important to scope out the route that you will navigate in your kayak on the water, but it’s also important to consider the route that your kayak will take from its blow-up area, to the spot where you actually ‘put-in’.
This is a high risk stretch of real estate where your kayak is concerned, so spend a few minutes making sure it is free of sharp debris, natural or otherwise, that could put quick end to your paddling plans.
High temperatures can lead to over-inflation. If you paddle an inflatable kayak, it should be pretty clear that sharp hazards are your mortal enemy. What is less-understood though, is that high temperature leading to over-inflation can also be problematic.
As we all know, heated air expands. If you inflate your kayak to its maximum pressure and then leave it on the hot ground or in the sun, the air inside will heat up and expand. This inconvenient phenomena puts pressure on the many seams of your boat. If left untended for too long, the structure of your kayak will be damaged.
Usually, the first structural components to tear are the septums. These are the seams that run the length of your hull, making it look like long cucumbers laid down side-by-side. When septums break, the long, skinny cucumbers end up looking like long, fat sausages (and it’s really hard to kayak on those).
To avoid this mess, transfer your inflated kayak to the water quickly as you can. Or, if you are exiting the water, either place the kayak in a shaded area, or remove the Boston valve cap to let out some air and reduce the pressure inside the boat.
Five techniques to identify the location of the leak
Regardless of how much love and constructive attention you show your inflatable kayak, eventually time will catch up and a leak will occur.
Don’t worry. They happen all the time and can usually be handled with a little time and easy-to-handle materials.
If you notice that your boat is losing air, then it’s time to find and fix the air leak in your inflatable kayak. The first thing you need to do is locate the leak. The difficulty in locating the leak dictates the technique you must use to find it.
Technique 1: Listen for the leak. Inflate your kayak in a quiet location. Turn your music off. Unplug your fans – at last for a little while. Inflate your kayak and just listen.
Position your cheek close to the kayak so that your sensitive facial skin can feel the air move.
Start in the valve area. A lot of kayak leaks occur in this vicinity and often, the valve is cross-threaded or otherwise not properly sealed. (This step is kind of like checking to make sure you plugged your computer in before calling tech support.)
If there is no air movement near the valve, then work your way around the various seams of your kayak. The highest-probability areas for pinhole damage are the bottom of the hull (made by external hazards) as well as the cockpit (made by you).
Pay closer attention by employing a grid strategy. If you are unable to locate the source of the leak on your first pass, you’ll have to pay closer attention. Divide your kayak into smaller squares. One square foot should do it but you could make them bigger or smaller. You could use chalk to actually draw squares or you might simply use your imagination.
The point of the exercise is to focus your attention on each flat surface and each seam in each square.
Remember to place your face close to the kayak material and listen as well as feel for air movement.
Go over each square in the grid until you have searched the entire kayak.
You might find the hole right away, or you might not find it at all.
If you find it, use a marker or grease pencil to circle the location of the leak so that you don’t lose it, again.
If you are unsuccessful at locating the leak in your kayak while it is dry, then you’ll need to get it wet.
Technique 2: Locate the leak underwater. If you have access to a body of water that is four-to-five feet deep and clear, then this should be your first ‘wet’ strategy to locate the leak in your boat.
Inflate your kayak and float it on the clear, still water. Put on a diving mask and take a deep breath.
Swim under the kayak and look up. You are looking for small bubbles pushing from the underside of the boat. They might come from a flat portion of kayak material or they might come from a seam. Just look for the bubbles.
If you find them, use a grease pencil or some other marking tool (that won’t create another leak) to mark the location of the hole. There might be more than one hole so, don’t quit until you have checked for more, unless of course you run out of oxygen.
Technique 3: Use soapy water to locate the leak. If you don’t have access to a beach with four feet of water, then consider the soapy-water strategy.
First, inflate your boat.
Next, combine water and liquid soap. Dish detergent is usually effective because it lathers well (and is allegedly gentle enough to clean crude oil off the down of a baby duckling).
Using a sponge, cover a single, modest-sized area with soapy water.
If there is a leak in your kayak, the moving air exiting your boat should create bubbles in the soap.
Go over the entirety of your boat, grid-by-grid, with the soapy mixture. If you find the leak, circle its location with a grease pencil or some other marking tool.
Technique 4: Move up to snow foam shampoo to find that pesky leak. If you are unable to locate the leak in your kayak with soapy water, the next step is to use snow foam.
Snow foam is a densely foaming shampoo that is used to wash vehicles. If you have ever taken your car (or truck) through an automatic car wash, then you have most likely been pelted with some version of snow foam.
In the U.S. and Canada, you can find a version of snow foam shampoo under the Turtle Wax brand. There are other brands as well.
In the U.K. you might use Demon Snow Foam.
The advantage of snow foam over soapy water is that the foam is thicker and its bubbles are more rigid.
Follow the bottle’s instructions to apply the snow foam, using either a hose or a power washer to apply. (A power washer actually applies a lovely, thick coating of foam that is very effective in finding pinhole leaks in inflatable boats.)
Once the snow foam has been applied, the location of any larger leaks should be manifest quickly. Similar to the soapy water technique, an air leak makes its location known by producing bubbles in the foam. Locating smaller pinhole leaks takes more time because the foam needs to settle onto the fabric of the boat before it is agitated by tiny amounts of air movement.
Apply the foam to your entire boat and then use the grid pattern to focus your attention on only one small area at a time.
If you are unsuccessful at finding the leak in your kayak with this method, at least you will have given your boat a first-class cleaning.
Technique 5: If nothing else is working, use plastic wrap. Who cares how clean your kayak is if you can’t paddle it because it is losing air. If none of the other techniques have worked to locate the source of your kayak leak, try this:
The key tool is plastic wrap. Some people call it clingwrap. Or Saran Wrap. You almost certainly have a roll in your kitchen to spread over the top of pots or bowls to keep food fresh while in your refrigerator.
You’ll need a couple of rolls of plastic wrap for this exercise.
To execute this technique, you must strategically cover your kayak with plastic wrap. This is not a one-day task. It should take a couple of days to do effectively.
Start with the bottom of the hull. Apply the plastic wrap tightly over the hull. Think about it like you are putting up wallpaper. You want to create a clean flat surface with no air bubbles. A small squeegee can help you push the air out.
Remember to push the plastic wrap as deep as you can into the crevices of the kayak. The more kayak surface area that is in contact with the plastic wrap the better.
Having carefully applied plastic wrap to the bottom of your kayak, let it sit for 12-24 hours. When you revisit it, look for new air bubbles that have formed under the wrap. These bubbles mark the location of your kayak’s air leak(s).
You may need to spend a couple of days on this process. A little bit of that time will be spent applying the plastic wrap. However, most of it will be waiting around for the air leaks to show themselves.
How do you seal a leak that you can’t even locate? If you are unable to locate your kayak’s leak, then it is most likely a tiny pinhole leak. Believe it or not, there is a solution to fixing a leak you can’t even find: Polymarine Sealflex.
If your kayak is constructed from Hypalon or PVC, then Polymarine Sealflex will seal your kayak’s pinhole leaks effectively.
It is important to follow the instructions provided by the manufacturer.
In brief, introduce the Sealflex into the inflation valve. (You might choose to use a funnel to keep things clean.) Next, inflate to as high a pressure as possible and roll your kayak around to distribute the Sealflex evenly inside the kayak. While continuing to roll the boat, pour out any excess liquid. Sealflex is air-curing so, over the next few days, partially deflate and then reinflate to introduce new air into the interior of the boat. This will help with the curing process.
Hopefully this helps seal up your invisible kayak leak.
What patch material and adhesive should you use?
If your kayak has an air leak and you’ve been able to find it, you likely used one of the techniques above. Once you have located the leak in your kayak, how do you go about fixing it?
Determine the material used to construct your inflatable kayak. It is important to know what your boat is made out of so that you can choose the correct material for the patch.
Inflatable kayaks are most commonly constructed from PVC or Hypalon (at least it used to be called Hypalon – for our purposes we’ll continue to do so). Other materials are used as well, including Nitrylon and urethane.
PVC is the abbreviation for Polyvinyl Chloride. It is quite durable. Also, it comes in more colors and is cheaper than Hypalon.
Hypalon is a chlorosulfonated polyethylene synthetic rubber. It is very durable, especially when coated onto polyester or nylon fabric. It is also more expensive than PVC. For context, the U.S. military uses Hypalon-coated boats. So, Hypalon is good stuff.
The material determines the adhesive. Once you know the material with which your kayak is constructed, you can determine the adhesive you require to repair a leak.
Inflatable boat adhesives come in the form of single-part and two-part formulations.
Single-part adhesives are applied just like glue and are useful for quick temporary repairs.
Two-part adhesives consist of a resin and a hardener. Use these adhesives for more permanent, robust repairs.
If your boat is constructed from PVC, then the adhesive you require is one that is PVC/urethane-compatible. A solvent-based polyurethane adhesive does a good job of adhering both plasticized and un-plasticized PVC.
If your kayak is constructed from Hypalon, a solvent-based polychloroprene rubber adhesive combined with its complementary curing agent will provide excellent adherence as well as resistance to heat, salt water and humidity.
***PRO-TIP: PVC Adhesive does NOT stick to rubber. PVC Adhesive DOES stick to Hypalon Adhesive. Hypalon Adhesive DOES stick to rubber.***
How do you actually fix that leak in your inflatable kayak?
You have located the leak, you know the material of your kayak and you have sourced a compatible adhesive. Finally, you can proceed to making that repair.
How to plug the hole in your boat. The size of the hole in your kayak determines the type of repair you’ll be required to make. If the damage to your kayak is more than 75mm in any direction, then you will need to apply an ‘inside patch’, followed by an ‘outside patch’.
An ‘inside patch’ is one that you place in the interior of the kayak. Here are the steps to apply it:
- Cut your patch so that it covers the damaged area plus an additional 30mm on every side. Make sure that there are no square corners. Either cut a patch that is round, oval, or at least rounded off at the corners.
- Using light grit sandpaper, sand the top surface of the patch and the inside surface of the kayak that will receive the patch.
- Wipe the two surfaces clean. Apply a solvent cleaner and let sit a sufficient amount of time so the solvent evaporates.
- Mix the two-part adhesive according to the instructions on the containers.
- Brush a thin layer of the adhesive onto both the patch and inside of the kayak tube (this last part will be a little tricky so, be careful). Let dry for 30 minutes
- Brush a second adhesive coat to both surfaces and leave 5-15 minutes until tacky.
- Lay a piece of polyethylene onto the tacky adhesive of the patch. Roll the patch and polyethylene together and insert through the hole.
- Once inside the hole, place the patch in position and remove the protective polyethylene piece. (This is a high-risk move so do it carefully and intentionally.)
- Press down with force. Using a smoothing roller, press hard on the outside of the patch and roll from one side to the other. The purpose is to remove all air pockets.
- Leave the patch to dry for more than six hours
- After the patch is dry, pump up the kayak to check for leaking air. Ideally, the inside patch should be air-tight.
Application of the ‘inside patch’ is challenging, but necessary for larger leaks.
Once you have completed and tested the ‘inside patch’ you can then proceed to apply the ‘outside patch’ as follows:
- With the tube inflated, create a masking tape border allowing a couple of millimetres of ‘stretch’ room in the material.
- Sand the surface of the kayak as well as the patch until it has a matte finish.
- Wipe the kayak and patch surfaces and clean with a solvent cleaner.
- Apply a first thin coat of adhesive to the kayak and patch and leave for 30 minutes until dry.
- Apply a second coat of adhesive to the kayak and patch and let sit 5-15 minutes until tacky.
- Position and place the patch on the kayak and smooth out any bubbles with a roller.
- Confirm that you have properly affixed all of the edges.
- Pull off the tape and remove excess adhesive with a solvent cleaner.
- Let sit for a minimum of six hours before applying pressure to the kayak.
- Allow 48 hours for a full cure and seven days for maximum strength.
While the procedure above seems long and onerous, it really isn’t bad. All you need to do is locate the leak, abrade and clean the material, apply some goop, slap on a patch, remove the air bubbles and wait. Boom! The repair is done.
If the leak is less than 75mm, you don’t even need to apply the ‘inside patch’.
How do you repair holes in the kayak seams? The repair template that you read above works smoothly for holes on the flat surfaces of your kayak. What about the leaks that form in the crevices and at the seams?
The truth is that the repair process for seams is about the same as for flat surfaces, but with a couple of extra ‘features’.
Separated seams want to keep separating. Even after you apply an ‘outside patch’, the pressure on the seam to continue to separate can break your repair-job. With this in mind, you’ll need to make a judgement call.
If the seam-hole is small and less exposed to pressure, then try a topical patch first.
If the seam-hole is greater than 75mm, you may need to don your surgical gear and apply both ‘inside’ and ‘outside’ patches.
The most successful seam-repair jobs that I have seen are ones that have employed significantly oversized ‘inside’ and ‘outside’ patches. My sense is that the large patches absorbed the pressure away from the seam, reducing the force that would normally press the seam and increase the size of the hole.
If you are unable to patch holes at a seam, just cover the hole with goop. This is more of a short-term, desperation-style hack.
Occasionally you might find that your patching efforts are unsuccessful. Rather than throw your inflatable kayak into the trash bin, try this:
- Abrade and clean the kayak surface well in the general area of the leak. (If you have a leaky patch-job, then you can be pretty sure that the leak exists somewhere at the edge of the patch.)
- Cut a disc or strip of insulating tape to cover the puncture, or general area of leakage.
- Liberally apply Aquasure/Stormsure or some other neoprene repair glue onto the offending area of the leak. If your first coat doesn’t look thick, then apply another.
- Apply Sealflex (remember this stuff from earlier?) to the inside of your kayak.
The combination of your patching attempts, plus Sealflex on the inside, plus neoprene glue on the outside, might just be enough to resurrect your kayak.
You might have to rename it Lazarus!
What if you spring a leak mid-voyage? If you are venturing out on a multi-day expedition in an inflatable kayak, bring: extra patches, ‘Gorilla Tape’ and a tube of AquaSeal.
Expedition repairs in imperfect circumstances require creativity and improvisation. If your kayak is impaired with a leak, then a big patch, a few strips of super-strong tape and a silicon-based adhesive will be able to fix almost anything that mother nature can throw at your boat (within reason, of course).
Parting thoughts about fixing air leaks in inflatable kayaks.
Air leaks are simply a part of the inflatable kayak experience. Not an enjoyable part, but not an unexpected part, either.
The gear necessary to repair these air leaks is minimal and the process is usually straightforward.
Make sure you have the correct patch material and adhesive, follow the steps, take your time, and your efforts will breathe new life into that limping kayak of yours.
Lazarus, arise!