Canvas to Slow Leaks ?

[SvenG]

The most recent issue of the Swedish Cruising Club magazine has an article about how to prepare a canvas triangle for stemming hull punctures or leaks.

I know sailboats used in shipping over the centuries would use canvas for that purpose but I'm wondering how effective it really is and if anyone carries such canvas with them these days ? It would be so easy to make but I wonder how likely it is that one would be able to put it to good use ?

BTW, the article also discusses training for sinking situations using a training boat. They have various pumps and go through what to do when you notice water coming in. Despite the preparations almost everyone ends up "losing" the training boat the first 2 or 3 practice runs. Not very comforting to know.



-Sven

[Minggat]

I Googled "collision mat" and came up with an old post I did here.

I carry one. Made out of international orange vinyl (better sealing than regular canvas)

Effectiveness. Can't speak from personal experience. Hope I never have the experience. I don't carry it because I think it will be ineffective though.

Being triangular, with a 20 ft line spliced into each corner helps to position it over a hole, depending on the cooperation of the hole. If the hole is foward of the keel it should be very easy. So best to attack the rock with your bow, instead of it attacking you from a blindside.

[MarkJ]

Instead of haveing a mde one the idea was you would use the storm jib.

We dont have a storm jib so we would use the genoa or maybe the Bimini if we needed to sail.

I have some underwater epoxy - not enough for a major repair like that, but that would be the modern idea, wouldn't it? Go over the side and plug it up with a few kgs of water setting goo.

[Minggat]

Originally Posted by MarkJ

Instead of haveing a mde one the idea was you would use the storm jib.

OK, fine. Purist.

Well, he did ask if anyone carried such canvas.

I thought the idea was to save the boat or something.

[MarkJ]

Originally Posted by Minggat

I thought the idea was to save the boat or something.

Absolutely, of course
I thought in the old sailing ship days they would just do the "Arrr me hearties, hand the T'gallant and stuff it in the 'ole".

And for us less likely to have t'gallants the jib is held over the bow, head to one side and tack the other and clew ith line attached. The head and tack are moved down the boat till its over the hole (as you say, far better the hole be foward of the keel), lashed down and the clew lashed too. The water trying to get in pushes it into the hole. neatly plugging it.

Ho ho and a bottle of rum!

I don't like the sound of that and laying odds it was going to work!

I watched Master and Commander the other night and they plugged from the inside driving a sail into the hold with a hollywood size mallet.

having not holed a boat, I wonder if those that have or have seen it, does the fiberglass when holed just flick back together? So a cover would stop water or does it need to be physically plugged?

Can I get the life boat out yet?


Mark

[rustypirate]

My understanding was that the canvas was stretched over the outside of the hole, reducing the flow of water coming in to allow for creating a more stable plug from the inside. The goal here is not necessarily completely stopping the leak so much as reducing the flow to a point where the bilge pumps can keep up with or handle the incoming water.

[forsailbyowner]

I ran into a rock and holed magic years back. I took a piece of canvas and smeared 5200 on it and pushed it over hole and squeegied excess out. Held hundreds of miles till I got her hauled, then wasn't easy to get off.

[mintyspilot]

I'm surprised that nobody has produced an "umbrella" that you can push through the hole, inflate and then pull back against the hull.

[Connemara]

Remember that those old hearts of oak boats leaked like a sieve at all times, so they were always pumping. The goal of fothering a sail across the hole was just to get the water flow back to something like normal.


Connemara

[MarkJ]

Originally Posted by Connemara

fothering a sail

Theres a salty old word....

[Connemara]

Originally Posted by MarkJ

Theres a salty old word....

Arrr, mates.


Connemara

[osirissail]

Originally Posted by mintyspilot

I'm surprised that nobody has produced an "umbrella" that you can push through the hole, inflate and then pull back against the hull.

Actually they did and didn't sell very many. It was a device similar to the "molly" used on wall plasterboard. Your insert it through the hull from the inside and then tighten a bolt to expand the part outside.
- - From reading "loss" reports of holed boats - those at sea generally hit something large like a floating lost container or some other vessel. One off Bermuda got holed by a submarine. These boats invariably sink so fast as you barely have time to deploy the liferaft.
- - Those holed on reefs/rocks have either been abandoned as it normally happens at night. Others have been salvaged by hauling them off the rocks/reef and using stuff like 5200 to smear patches on the cracks.
- - Rather than sustaining a round hole with FRG boats the hull is crushed and pushed in with lots of radial cracks. Here the blanket or even a cheap poly tarp can work to slow the leakage.
- - I would suggest the skill and cool-headedness of the new modern sailor is not conducive to recognizing and taken action to "save the ship." I have more often seen new catamarans and mono's run up on the rocks and the occupants jump off and run to the nearest telephone to tell their insurance agent to cut them a check so they can buy another one.

[Minggat]

Originally Posted by osirissail

- - Rather than sustaining a round hole with FRG boats the hull is crushed and pushed in with lots of radial cracks. Here the blanket or even a cheap poly tarp can work to slow the leakage.
- - I would suggest the skill and cool-headedness of the new modern sailor is not conducive to recognizing and taken action to "save the ship." I have more often seen new catamarans and mono's run up on the rocks and the occupants jump off and run to the nearest telephone to tell their insurance agent to cut them a check so they can buy another one.

Remember the old days? At least on TV, when somebody got hurt, the call was "is there a doctor in the house?" Now it's, "Is there a lawyer in the house?"

A close friend of mine lost her boat off of Catalina last fall. Actually 2 boats went down in the incident and 5 people went into the water. All had some injury. My single friend had a couple on her boat. That couple, who were close friends of hers, are now sueing for pain and suffering. Not the first time I have seen this (legal manuvering) since I've been boating

No canvas hole plugging would have helped (just to keep from thread drift here).

[SvenG]

Originally Posted by Minggat

A close friend of mine lost her boat off of Catalina last fall. Actually 2 boats went down in the incident and 5 people went into the water.

Is it ok to cause drift of a thread you yourself started ?

We heard that whole event over 16 as it was happening. It was very gripping with only one side of the conversation heard, the various coast guard vessels and other rescue resources. Later we found out that both boats were from our marina and I think they were both live-aboards. In addition to the broken arm and other injuries both owners literally lost their homes. It sounded as if the second boat was lost trying to render assistance to the first by pulling it off the rocks.

To bring it back to the thread topic ... I wonder how likely it is that a novice would know how to use the canvas, would have time to get it out and that it would actually help. As mentioned further up in the thread, catastrophic holing or washed up on the rocks seem to be the common ways of losing a boat, not a hole that can be managed.

Despite my doubts I'll probably make such a canvas just in case we should ever have such a fortunate misfortune that it might help.


-Sven

[Minggat]

Yes, both livaboards. Next door neighbors in fact.
Yes, 2nd boat lost trying to render assistance- but boat #1 not yet on the rocks. #2 fouled his prop in kelp/overheated during the attempt.

You bring up a good point. If you're stick on the rocks/surf all your effort may be in vain and you would be further endangering yourself. Going below and trying to plug from the inside would make you vulnerable to being trapped inside at the worst time.

Thank you for the mental image.

Certainly there are scenarios where whatever "collision mat" you can get your hands on would be more workable than that one. Ideally we would all be novices at it. Also ideally, we never use out liferafts, fire extinguishers, EPIRBS..... insurance.....