Crash Blankets and Hull Damage

[Stillraining]

Just got done reading an article in 48* North about MacGyvering at sea.

In it there was talk of being prepared for just about any eventuality by caring odd bits of this or that which in turn can be used to Jerry rig some fashion of repair to get you by until a permanent fix is available.

Personally I have no questions or at least very, very few of my ability to do such things, some of you would probably shake your head at the amount of bits of stuff I pack on-board "just in-case" for our, so far inland sailing experience only...Katie bar the doors once we head off shore

All of this with one caveat....and that is for those things that go bump in the night compromising the hull directly, not a through hull or any of that lot... requiring quick action to not only locate the damaged area and source of water intrusion but effectively stopping such intrusion.

I know there is such a thing as a crash blanket and that also a spare sail will work as well...my question is How well do these work and does any one have first hand or second hand knowledge of there usage and how successful it was.

I have no experience with Marine-Tex either and was thinking of buying some for some underwater experimentation.. Not much concerns me regarding the ins and out of survival afloat....staying afloat concerns me a little....

Ya! Ya! buy a multi hull I can here it already...give it a rest or ill chain saw your hulls in half and prove you wrong..

All suggestions other then that one are welcome.

[Allanbc]

Carry a Nerf football. Actually, I found a three pack of Nerf balls that I put on the boat in case of emergency!

[Boasun]

In the last Century the Navy use to carry your crash blankets, but we called them "Collision Mats". Used to cover underwater holes in the ship and slow down the flow of water to where we don't want it.
But you can use a small sail or sail bag to do the same OR.... have the person with the largest Arse on board plump his/her Arse into that hole....

[sailingdog]

The idea of carrying nerf balls in various sizes as well as epoxy putty that can be applied and cures underwater are both good ideas. You should also carry some thin sheets of plywood and screws.

Of course, none of this does much good unless you have fairly good access to the hull's interior, which is often not the case with boats that use hull liners.

[sailor50]

We carry an axe just for that purpose - if there is a failure behind the galley cabinets we can't get to, and if the boat is swamped - an unlikely scenario - we have a way to get a lot of excitement getting to the leak, and get the bilge pump going overtime!

Also works good on chopping fruit in third world islands, fits conveniently in a back pack for added security while touring - doesn't do so well going through airport screening though!

[Stillraining]

Originally Posted by sailingdog

The idea of carrying nerf balls in various sizes as well as epoxy putty that can be applied and cures underwater are both good ideas. You should also carry some thin sheets of plywood and screws.

Of course, none of this does much good unless you have fairly good access to the hull's interior, which is often not the case with boats that use hull liners.

This begets the question:

I always figured the outside was the place to affect the initial repair as water pressure will be working for you not against you.

I like the Nerf ball Idea for a small clean puncture and Ply wood ideas...not so much the attachment of it and the screwing into the fiberglass though from the inside ...maybe once the main flow has been abated it would work with the aforementioned epoxy as a final stem of flow ( are we talking Marine Tex here or something else? )....

Having spent years trying to stem the flow of ground water into various concrete structures I have learned attacking it from the inside is all but fruitless..it needs to be dealt with from the pressure side....Im not talking a nice clean hole scenario here ...Im talking fractured jagged cracked fiberglass.

Good discussion... keep it going.

Sailor 50: Great idea on the ax...I did not know it was a CC requirement until just recently ...either learned here of on another fourm...Thanks for reminding me ..I had forgotten already..

[Hartley18]

From what I've heard and read from people in actual collision situations, I don't think bits of plywood and a few screws are going to help much. Collisions rarely happen in nice calm weather or in flat parts of the hull and the pressure and quantity of the water coming in through even a small hole is truly amazing. Somehow I think the only way "plywood and screws" will help is if it can be screwed in on the OUTSIDE of the hull - using a waterproof screwdriver?? Sure..

For a serious hull puncture of any size, I'd think you don't have time to locate Nerf balls.

First thing: LOOK UP to make sure the rig isn't about to come down on your rescue efforts.
Second thing: Once you've located the puncture, I've always been taught to grab a seat cushion, fold it into a loose ball and wedge it against the hull using a floorboard - this is to slow the leak, not stop it - then take a breath, get someone pumping if they aren't already and think about dragging a sail, tarpaulin or even a plastic bag over the outside, secured with rope (sheets, mooring lines, whatever comes to hand) IF you can do so safely without losing anyone overboard. Water will still come in, but the bilge pumps should be able to handle it from there. The seat cushion acts as a brace to prevent the sail/whatever on the outside being pushed into the hole and failing to seal properly.

It has long been said that the best, most effective bilge pump is a scared crewman with a bucket!..

[Stillraining]

I like Dogs plywood idea may be with

Originally Posted by Hartley18

From what I've heard and read from people in actual collision situations, I don't think bits of plywood and a few screws are going to help much.

For a serious hull puncture of any size, once you've located the puncture, I've always been taught to grab a seat cushion, roll it into a loose ball and wedge it against the hull using a floorboard - this is to slow the leak, not stop it - then take a breath, get someone pumping if they aren't already and think about dragging a sail or even a plastic bag over the outside, secured with rope (sheets, mooring lines, whatever comes to hand) if you can do so safely without losing anyone overboard.

I can see this.

My thinking however continues down the road and some one eventually will NEED to go overboard...preferably in day light and calm seas but maybe not depending on how bad it is...But I agree an outside plug is going to be where its at in my pee brain thinking.

I remember This spring when there was a boat lost due to through hull failures with in a day or two sail from port..they put a man overboard to bang in a plug but that didn't stop the flow...here again it probably wasn't a nice clean hole they needed to plug....Right action wrong method.

I like Dogs plywood idea for some areas of the hull...may be with some neoprene sand witched between it and the boat....but yes a compound curve would be difficult

[Hartley18]

Originally Posted by Stillraining

I like Dogs plywood idea for some areas of the hull...may be with some neoprene sand witched between it and the boat....but yes a compound curve would be difficult

Still, it might be a good idea, but it doesn't work in practice. Yes, it needs to be secured on the outside of the hull, but there is usually no way (assuming a plastic boat here) you can fasten the plywood in place long enough for the glue to hold.

If you doubt me, try this next time you borrow the neighbour's fibreglass dink.. on a nice day in an anchorage with slight chop:
1. Pre-drill some screws into corners of some scrap ply using your cordless drill.
2. Go swimming (wearing a lifejacket) - don't drop the cordless!
3. Try to drive the screws into the hull of the dinghy - start above water if you like - you'll experience great difficulty in:
(a) Holding the sheet in the right place with one hand whilst holding the cordless above water with the other and,
(b) Penetrating the gelcoat with the screws.
4. Try and work out how you'd get the screws in below water level.
5. Go buy a wooden boat - you can use nails then!!

A better idea:
1. Leave the thin plywood at home and select an appropriately-sized plywood hatch cover from elsewhere on the boat. There's usually quite a range to choose from..
2. Tie a rope to the finger-hole and position it over the outside of the hull. Use a sealant if you like, but you'll only end up with a sticky mess inside the boat as it gets torn off by water pressure before you can get the patch in place. Some Epoxy Putty might work to slow the leak even further, though only over a small hole, but will probably crack off with flexing of the damaged hull.

[Stillraining]

Hartly:...I see the mechanics of what you speak...I have done enough diving to now remember the difficulty of keeping yourself against something in a neutral gravity less environment.

This is all the kinds of thought process I was hoping for in this thread...using the knowledge bank of the community to solve this one for me..

Your appreciated buddy!

FWIW I love wood boats...actually bought one and it disappeared into the pacific somewhere on delievery..