How To Make An Unsinkable Boat
- #1
Has anyone used two part polyurethane foam in their boat to keep it adrift if it gets holed? I need 2.5 cubic metres in mine. I need to put it under the decks in the void spaces, I plan to put it into tough plastic bags to cease it sticking to the boat.
Tin can anyone offering whatsoever advice before I kickoff please?
- #2
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Roger Taylor, the guy thats sails single handed and author of various books on uncomplicated sailing does this. He describes the process in his books and I believe (just cold be wrong) on his web pages likewise. It's office of his preparation for the long voyages. He packs the forecabin, or a stern surface area and then seals the space in to stop the foam breaking loose.
- #three
Expanding PU cream tin produce substantial pessures which have the potential to distort your boat.
In the past I worked for a company which injected PU foam into boats for buoyancy and we constitute it necessary to put the boat assembly into a pressure level mould to prevent distortion.
The larger the foam volume the more pressure is produced.
- #4
Downsman
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No personal feel, but I take seen an old dinghy that someone tried to add bouyancy to past using expanding foam. All I would say is be very careful because the expansion ability seems to be considerable. Whoever doctored the dinghy got information technology wrong and divide the fibreglass locker/space that they poured the poly mix into. I suppose if there'south plenty of room for information technology to expand it's ok, but I don't really know.
Ha! There y'all become...run into post above..
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- #v
Thanks, I plan to put it nether my decks, I can unscrew these to relieve the pressure and trim the overspills.
- #6
dartmoor
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I would recall virtually it very carefully first. PU foam has many voids and tin end up retaining water - which would add weight, and could even advance osmosis.
Wisest thing I heard from a gunkhole architect - any boat will sink in some circumstances. Better to concentrate other prophylactic measures imho.
Only there are better things than PU foam which are much much more than water resistant. PU foam is a building substance actually - not a buoyancy device
- #7
Closed cell foam is waterproof.
- #8
Tranona
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Non really practical in most cases to retrofit that amount of buoyancy for the reasons already suggested. Those builders who have tried to do it in their designs such equally Sadlers and Etap have made two carve up hulls, put one within the other and injected foam between them You need closed jail cell foam and it is not like shooting fish in a barrel stuff to use, nor does it always fill the voids.
The risk of a boat sinking is very small and as others take said, amend to put the endeavor into avoiding sinking in the first place.
Yet, if y'all desire emergency buoyancy then possibly look at inflatable numberless activated by gas such as are used on cocky righting inflatables and RIBs. Or, if as you say you accept voids why not have air filled bags made to fill the voids?
- #nine
It goes on expanding, with considerable enthusiasm, later on it has stopped flowing.
- #ten
Its non just a question of making the boat unsinkable, its the stability and inhabitability of the boat once its flooded that as well matters. Its all about the GZ bend of the boat once its swamped vs the GZ curve when its floating to its lines. In addition, the static and dynamic stability needs to be taken into business relationship in your calculations.
Sorry to exist the bearer of negative news, but making a boat unsinkable isn't merely a affair of providing positive buoyancy.
- #11
Neil
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Does anybody sell inflatable bags that you could take out of a locker and pull the cord and inflate inside the boat - one forecabin-size and another like to (say) fill up a stern quarter berth? would it be enough?
- #12
Downsman
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Not sure about the size when inflated, but don't some rescue/emergency ribs take an inflatable bag on the stern gantry that inflates if they plough over? Maybe the firm that supplies those would be worth contacting.
- #13
How do you sink a boat with positive buoyancy?
- #14
You're all obsessed with not sinking. How many of you take ever sunk? Y'all're insured, I promise. How most concentrating of staying live instead?
I take thread running on buoyancy on PBO. I am adding very piffling.
- #15
Tranona
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Not certain nigh the size when inflated, only don't some rescue/emergency ribs have an inflatable bag on the stern gantry that inflates if they plow over? Maybe the business firm that supplies those would be worth contacting.
See post #8. Yes you can go them made. Henshaws who made the Tinker used to make them and probably still do.
- #16
I've done it, in the bow of a little trailer-sailor (Sealord fifteen/Seafarer 465). There was a 'sealed' foam-filled compartment in the bow (and another nether the deck), I cut a 8" hole in information technology, with a view to plumbing equipment some watertight storage, and found the foam to be quite soggy - I recollect from 20-odd years of rain leaking in through the deck fittings. I removed the foam through the pigsty - this was a hellish job, in the end information technology would take been much quicker and easier to remove the whole top of the compartment. Refilling it was easy - mixed up the cream in small (100ml?) batches in single-use plastic beakers and (quickly) poured it in. I recollect I left about 10-fifteen minutes between each batch to give information technology time to expand, I also dampened the surface with a plant mister between batches, thishelps promote the reaction. I did it over 2 days, and was surprised how much more than it had expanded overnight, and then just be careful! You lot need a warm twenty-four hour period, although the cream does produce some heat itself. Y'all also needs lots of ventilation as the fumes are very unpleasant (toxic?). Don't wear your best apparel, do wearable long sleeves and disposable gloves. When the foam is set, you can cut it back with a knife/breadknife/hacksaw bract and glass over information technology.
Equally far as flotation went, It worked fine; I had to exit the boat on a mooring over one of our particularly bad winters a few years ago, the cockpit drain blocked and the cockpit and cabin flooded during a really heavy downpour. Information technology didn't do the boat any good, merely it didn't sink!
(Edit) Just re-read the start mail service - 2.five m3 is a lot of space and a LOT of foam! I think I did about 80 litres. It may exist easier, and cheaper, to go it washed professionally - something like this?
http://www.youtube.com/watch?five=473A8ocG4ok
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- #17
Perhaps I wasn't explicit enough in my last postal service.
Assuming you manage to fill some spaces with foam and assuming that the so called 'airtight prison cell cream' doesn't go waterlogged, what makes you think that the boat will float the right way upwards if information technology ever floods? You might stop up with a boat that's upside downward and merely a danger to yous and other vessels.
I will repeat a little of what I said earlier: making a boat unsinkable isn't merely well-nigh making sure information technology stays afloat. How the gunkhole volition behave when its flooded is almost only as important if the 'unsinkable' tag is going to mean anything. Otherwise you are just using upwardly storage space on board to no skillful affect.
If you are really worried about sinking buy a liferaft and fit it in a cradle with car-release.
- #18
Perhaps I wasn't explicit enough in my concluding post.
Assuming you manage to make full some spaces with foam and assuming that the then called 'closed jail cell cream' doesn't go waterlogged, what makes you think that the boat will bladder the right manner upward if information technology always floods? You might end upwards with a boat that's upside down and only a danger to you and other vessels.
I will echo a trivial of what I said before: making a boat unsinkable isn't just about making sure it stays adrift. How the boat will comport when its flooded is almost just as of import if the 'unsinkable' tag is going to hateful anything. Otherwise you are but using up storage infinite on board to no good affect.
If y'all are really worried nigh sinking buy a liferaft and fit it in a cradle with motorcar-release.
Done that, got a liferaft, got the teeshirt... I need to at least go through the motions of sealing my decks in able to get my MCA code, the mecal survayor is quite directly down the line on this one.
- #19
Contacted them,put on the dorsum burner u til I accept explored every other artery due to the hellishly expense options they quoted.
Merely thanks for the link.
- #xx
Holt Buoyancy Bags might be a simpler reply.
I do recall, when I worked for the importer of Pioner boats, the boat sales managing director used to cut open up the Pioner Multis for certain fit-outs, fill the inside of the hull with a load of small, one/2ltr plastic spiral cap bottles and so re-weld the hull for added buoyancy in certain applications.
Source: https://forums.ybw.com/index.php?threads/making-a-boat-unsinkable.399125/
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