Can you repair a liferaft at sea?
All liferafts are sold with liferaft repair kits, but are they any use at sea, when it’s a matter of life or death? Ben Meakins finds out
Can you repair a liferaft at sea?
‘A horrendous sound like the ripping open of a huge zipper meets my ears. Air blows out in a spluttering, heinous burble. If I cannot repair the damage, I won’t last long.’
When Steve Callahan’s liferaft was punctured by a malevolent dorado on his 43rd day adrift in mid-Atlantic, in 1982, it was a case of out of the frying pan and into the fire.
It’s every sailor’s nightmare. It’s bad enough that you’ve taken to the liferaft, but when that springs a leak, what can you do? You’d think in these days of EPIRBs and satellite phones that your chances of having to spend over 24 hours adrift were limited – but as recently as November 2008, two delivery crew spent four days in a raft off the Spanish coast near Minorca after their yacht sank. The boat was hit by a wave and sank before they had a chance to send out a Mayday, set off their EPIRB or even pick up their grab bag.
Plenty has been written about surviving in a liferaft, but little has been said about how to repair one. We took to a liferaft armed with a sharp knife and a variety of bungs and bodges to find out whether it’s possible to make a decent airtight repair while at sea
A benign sea state in Andark’s pool near Hamble. At sea, it would be much harder
We classed possible repairs in four categories: clamps, leak stoppers, glue and patches, and lastly, ‘the bodge.’ We used a Eurovinil Ocean Standard budget four-man raft, trying each method of repair on three different sized holes: pin-pricks, 1in (2.5cm) and 1½in (3.8cm) holes.
We tried each method out of the water first, before launching the raft in Andark’s dive training pool near Southampton and doing the same in the water. The difference was startling.
There’s no guarantee of what you’ll find in your repair kit. The new ISO 9650 standard for liferafts says that, as a minimum requirement, ‘repair outfits must enable survivors to repair leaks in any or all of the inflatable compartments. Repair systems must work when wet and be capable of being applied during violent motion.’ All well and good – but even if you’ve got a raft that complies with the standard, you have to take the manufacturer’s word for what’s in your kit. As we found, it’s worth checking.
Partial deflation means you’re almost always working underwater
Some manufacturers supply clamps as part of their repair kit. Clamps have many advantages over cones – not least that they are more secure. They do need to be on a flat surface, however, so aren’t as good as cones in corners or for holes near seams.
The hole must be big enough for the clamp to pass through
This clamp will repair holes from 2½in to 3¾in (6cm to 9.5cm). You may need to enlarge the hole. It was easy to push half of the seal through. We then pulled on the string and the two halves lined up and joined together – by far the best method of all we tried.
The upper clamp lowers onto the thread and screws up tight
A tiny stream of bubbles came from the centre of the screw thread no matter how much we tightened the nut. With the thicker fabric of a more expensive raft, perhaps it might form a better seal. Nevertheless, after an hour afloat there was no noticeable difference in the raft’s tube pressure.
The best option on test, though air still bubbled through the thread
We didn’t test any other clamps, but the principle is certainly sound. Those that came with the Seago raft (not sold separately) are metal, the two halves secured by a wing nut. There’s a long, twisting wire to hold, which stops you losing the inner half inside the tube.
Verdict: The quickest, most secure method we tried. Well worth a place in your grab bag
Glue and patches
‘Dry area… clean with alcohol… don’t reinflate for 24 hours…’ Patches are not a practical solution
The instructions on the glue bottle said: ‘Dry area. Clean with alcohol… Apply the patch after two minutes, eliminating any air bubbles. Put a weight on and inflate after 24 hours.’ Clearly, this would by okay on dry land but a challenge in the water.
We did our best. It was impossible to get the glue to stick to such a wet surface as the bottom tube. A small slice in the top tube was slightly easier to keep dry, but as the air leaked out it dropped ever closer to the water. We applied the glue to both surfaces, waited two minutes and clapped on the patch. Placing a weight on the repair was not possible, so we used duct tape to keep it relatively dry and protected.
Our time in the pool was running out – and waiting 24 hours would be impractical in a liferaft. Reinflating after 30 minutes, the patch held for five minutes before it succumbed to the inevitable.
Glue and patches were fine for mending the canopy, where the repair needn’t be airtight and can be kept dry. Duct tape, spinnaker repair tape and mainsail repair tape also worked well on canopy holes.
Duct tape did as well as the patches, so it definitely makes it into my grab bag
Verdict: Back in the warm, dry office, we followed the instructions to the letter – and the repair was as strong as steel. But afloat, it’s just not practical.
We had a variety of leak stoppers. These are threaded cones, made of rubber or plastic, which screw into the hole to seal it.
Rubber leak stoppers
Many liferaft manufacturers supply rubber bungs. They aren’t sold individually
These were hollow and as soon as we tried to screw the round bung into the elliptical hole, the rubber just distorted and the bung refused to go any further.
The cone collapsed under pressure
Under water, it worked a little better – the water acting as a lubricant – but we couldn’t screw it in far enough to make the hole airtight.
The smaller bungs were better as there was less of them to distort – but no good for any holes bigger than an inch (2.5cm).
Plastic leak stoppers
The second best option but more vulnerable than the clamp
These were much better. Solid and with a good hand-hold at the base, they forced the rubber around the hole into a circular and thus airtight shape
Small white cone (Zodiac)
Zodiac’s cones were rigid but needed deeper threads
With a tapered thread, and smooth tip, it was easy to screw in and sealed small holes – up to ¾in (2cm) – with no leakage. However, the relatively shallow thread is vulnerable to being dislodged
Large white cone (Zodiac)
This also had a shallow, tapered thread. The same size as the Viking cone, it sealed the hole just as well – but the lack of a good grip made it more difficult to screw in. The biggest hole it would seal was 1¾in (4.5cm).
Red cone (Viking)
The Viking cones had much better grip than the Zodiac ones
The deep thread on these cones meant that they bit into the edges of the tear and made a good airtight seal. A good ‘grip’ made it easy to screw them in enough to stop any air coming out. The deep thread also made the cone much more secure and less vulnerable to being forced out.
These cones are good for medium-sized holes – up to 1¾in (4.5cm) long.
Verdict: Conical leak stoppers are particularly good in corners or other places where abrasion rubs a hole in the fabric. The plastic ones were far better than the rubber stoppers, which distorted. It would be worth tying them on with a lanyard in case they are knocked out of the hole. While not a permanent solution, they should keep you afloat.
The lifesaving bodge
A great theoretical solution but useless in practice
The Captain’s Guide to Liferaft Survival, by Capt Michael Cargal, suggests putting a softwood plug into the hole and sealing the edges of the torn rubber around it with a jubilee clip. In principle, it sounds like a workable idea. A 10mm-diameter wooden bung did a good job of plugging a pin-prick hole, but air bubbled out constantly through the grain of the wood. We tried with a bigger hole. Ashore, we succeeded, to some extent. We secured the plug, but it was difficult to get enough slack in the rubber to pull it far enough up around the bung, and it leaked air despite our best efforts. The sharp edges of the jubilee clip began to chafe horribly, too.
Even on dry land it was difficult to create a decent seal
In the water, we tried again. As soon as the bottom tube had deflated it disappeared under the raft, resisting all efforts to pull it back. Trying to insert the bung, place the jubilee clip and tighten it while making it airtight, all out of sight beneath the raft, proved impossible, even with a second pair of hands. Trying from in the water merely complicated matters. Our hole was near the door – and doing it elsewhere would have been even more difficult.
Steve Callahan used a similar method to repair his raft. He had picked up some closed-cell foam flotsam from his sinking yacht. He placed it in the hole, sewed the lips together with thin twine and then wound string around the repair as a tourniquet to seal it. After some trial and error, he got this to work, and it kept him alive across the Atlantic.
What this goes to show is that a well-prepared grab bag, with additional supplies, materials and tools, is invaluable. Sikaflex or a similar sealant will cure underwater. Closed-cell foam, plenty of light line and a roll of duct tape would greatly increase your chances of making a successful repair.
Noe of the repairs created a perfect seal but some were much better than others
Hopefully, you’ll never have to use your liferaft – but if you do, you certainly won’t regret time spent ensuring that you have the means to repair it. Check the contents of your raft’s repair kit.
None created a perfect long-lasting seal but the clamps were best
Glue is fine for canopy repairs but completely impractical for mending tubes. Cones are vulnerable, but work well on small and medium-sized holes. The hard plastic variety work better than the hollow rubber ones. Clamps are ideal for larger holes, and are secure and easy to use. It’s well worth keeping a couple of Barton Clamseals in your grab bag.
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