A failed inner valve could spell the end of an inflatable tender – but Jake Frith has a fix

Inflatable boat valve replacement: step by step

All inflatable boat valves have an outer component that houses the dust cap screwed into an inner component through a reinforced hole in the fabric of the boat.

Outer valve problems are usually easily surmountable; you just unscrew the outer component – ideally using the correct manufacturer’s tool – and then replace it.

The inner valve part consists of the valve itself and the valve basket, which is simply a cage of some sort around the bottom of the valve that allows air in and out but does not allow the valve to drop into the tube.

This inner valve component is, by necessity, larger than the hole in the boat, and was fitted from the inside during manufacture.

This meant that replacing the completely disintegrated valve basket on my 25-year-old Zodiac would involve making a large enough incision in the tube to replace the inner valve part, before repairing that incision.

As I had a spare valve of the right size, and the boat would otherwise be scrap, I thought it was worth taking a chance to try making a repair.

Inflatable boat valve replacement: Step by step

An inner valve for an inflatable boat

1. When I got the inflatable out of storage in the spring I was met with a black hole where my starboard valve should have been

An inflatable inner valve on an inflatable dinghy

2. As an example of what it should look like inside, here’s its undamaged sister valve on the boat’s port hand side.

A homemade valve replacement tool

3. Lacking the manufacturer’s valve removal tool, I made one up from an offcut of 18mm plywood and four M5 bolts appropriately spaced.

an inflatable boat valve being replaced

4. To my great surprise, the homemade tool worked perfectly, locking into and unscrewing the outer valve part in seconds.

An inner valve replacement on an inflatable boat

5. Flipping the inner valve part round in its hole reveals the damage; the valve and basket have snapped off into the tube.

A man cutting an inflatable boat to access the inner valve

6. I seldom use the floor slats and the front one seems to do the least, so I sacrificed its retaining hoop for some matched PVC patching material.

A man using a knife to cut into an inflatable dinghy to access the inner valve

7. After deliberating for some time on where to best place my incision, I made it up by the bow, opposite the damaged valve.

A man with his hand inside an inflatable boat

8. Time for a good rummage in the Zodiac’s intestines to retrieve all the broken valve parts. Vets roll their sleeves up for these sorts of activities.

Parts of an old inflatable boat

9. I assaulted a dead inflatable on a beach with a Stanley knife about five years ago and threw the bits in a box in the loft. Only now do I realise why!

A man replacing an inflatable boat valve

10. The ‘new’ valve was the same size and screwed in perfectly. Lacking the correct tool I ground a pair of flats in the outer flange to spanner it on tightly.

A man using a plastic bag during an inflatable boat valve replacement

11. I cut a piece of plastic bag to go in the tube behind the repair to stop adhesive from gluing both sides of the tube together. It’ll live in the tube after.

A man marking an inflatable boat in order to cut the material

12. I cut and marked a patch and applied the two-part PVC adhesive in two stages to both surfaces, according to the instructions.

A man using a clamp during inflatable boat valve replacement

13. I masked the repair area and clamped the section to a short plank to ensure a flat area – you only get one chance to fit the tacky patch.

A new white valve on an inflatable boat

14. After clamping the repair patch overnight, it was time to inflate the boat and see how my salvaged valve and tube repair were performing.

a brown mark on an inflatable boat

15. I bevelled the edges of the tube repair with some Sikaflex sealant to help prevent the patch from getting picked up at the edges and stuck some 3M UV-resistant duct tape over the top for good measure. Spraying soapy water all around the valve and tube repairs revealed no leaks, and leaving the boat inflated for a week confirmed the success of the job. It’s not pretty – but it works!

Inflatable boat valve replacement: Reflections and lessons learned

Because my previous inflatable tube repairs have involved small holes, not self-inflicted 3in-long gashes, I never thought to include an inner patch.

My repair looks to be excellent and thanks to using the correct two-part adhesive should be long lasting, but some extra peace of mind might have been brought by incorporating an inner patch, perhaps of a larger size than the outer one.

You’d 100% need the polythene bag in the tube trick if effecting a repair with an inner patch.

a man applying petroleum jelly to plastic

Petroleum jelly keeps plastic threads running free. Credit: Jake Frith

I took time to grease up all the plastic on plastic threads and the rubber on the plastic valve and cap seats with petroleum jelly.

This helps seal any possible valve leaks and means the valve will unscrew much more easily next time.

If this was a higher end inflatable, I could have inflicted the gash elsewhere and hidden it with a lifting handle, seating pad, boat name or similar disguise.

Continues below…

As it’s a fix to get another season or two out of an ‘end of life’ boat, I was not concerned about the aesthetics.

It is a minor annoyance that I have to now take two different pump adapters everywhere for the two different valves I now have, but I have another grey replacement valve if the remaining black Zodiac valve packs up, so I may yet have matching valves!

People give you extremely funny looks when you go through beach trash and the big bins at marinas looking for things like inflatable valves, strips of repair fabric etc.

Successful and satisfying low cost repairs like this one, however, inspire me to carry on these eccentric activities.

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