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Another heads up re. closing rear hatches

Re: Another heads up re. closing rear hatches

Postby laneends » 21 Feb 2018, 21:09

Bulkheads in a plastic yak would create high spot ridges across the bottom as plastic hulls deform and flatten especially over time. These would be weak spots for wear and splits. This is why the bottom of mast posts and drive well lips can get badly rubbed on Hobies. I think it is also why OK moved away from a central scupper hole that was on the scupper pro, due to wear splits at that point.

Good idea to have your own internal flotation front and aft.

Touring kayaks have bulkheads, not sure if the plastic ones do, but they have less of a flat cross section that SOTs do so may not flatten the same
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Re: Another heads up re. closing rear hatches

Postby Seasherpa » 21 Feb 2018, 21:14

cruiser wrote:I see were you are comeing from guys but we should not be doing all this i have type 2 pdfs inside the yak to help keep it boyant ,the manufactures that make yaks should make them fail safe period ! so in the event things go south you have some sort of chance


There are regs in place for this sort of thing already Crusier, depending on where they are made. the small vessel buoyancy requirements both over here and in South Africa the is 30% of the gross kayak mass. I'm not sure what the American standards are as they don't affect me, but I assume Hobies would be built according to the standards in the country of origin (last I checked they weren't all made in USA) but I'm sure Josh could shed more light.
The other issue is that by nature kayak fisho's like to tinker and pimp and sometimes this can be to the detriment of the intended design so even though the regs are in place really a kayak is only compliant until someone tinkers with it. People put holes in bulk heads, and in hulls below the waterline often without using sealants none of which will help a kayaks ability to float. The other main problem is that kayak fishers often have their kayaks setup with incorrect weight distribution. As a result of using the most readily available and easily accessible space - rear wells most fishing kayaks are rear heavy due to livewells, eskies, milk crates with anchors, trolling motors and batteries. In reality fishing kayaks probably need to conform to a scaled down version of the large vessel regs - 60% buoyancy with a distribution of 50% at the rear, 25% in the middle and 25% at the nose.
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Re: Another heads up re. closing rear hatches

Postby laneends » 21 Feb 2018, 21:56

Bulkheads would also make draining a pain, as each would have to be done separately. if your front hatch for example started taking on water in rough weather you might find yourself nose down pretty quick and taking on even more and you wouldn't be able to pump it out safely
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Re: Another heads up re. closing rear hatches

Postby Seasherpa » 21 Feb 2018, 22:07

laneends wrote:Bulkheads would also make draining a pain, as each would have to be done separately. if your front hatch for example started taking on water in rough weather you might find yourself nose down pretty quick and taking on even more and you wouldn't be able to pump it out safely


I think bulkheads are a great safety feature. In the case above they would limit the amount of water the kayak would take on making it more likely to be able to pump it out. Modern bulkheads are installed as floating members now too which largely elimates the problems of stress points in the hull. You also don’t have to drain each compartment separately if the bulkheads are done with a bung in the bulkhead itself as is common. That is how the bulkheads are installed in the Toura 17 allowing you to drain the whole boat from the front of desired. The first gen Evos has a drain plug on either end of the ski and wasnt a big issue to drain, small price to pay for the compartmentalisation of a potential flood.
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Re: Another heads up re. closing rear hatches

Postby cruiser » 22 Feb 2018, 07:31

Seasherpa wrote:
laneends wrote:Bulkheads would also make draining a pain, as each would have to be done separately. if your front hatch for example started taking on water in rough weather you might find yourself nose down pretty quick and taking on even more and you wouldn't be able to pump it out safely


I think bulkheads are a great safety feature. In the case above they would limit the amount of water the kayak would take on making it more likely to be able to pump it out. Modern bulkheads are installed as floating members now too which largely elimates the problems of stress points in the hull. You also don’t have to drain each compartment separately if the bulkheads are done with a bung in the bulkhead itself as is common. That is how the bulkheads are installed in the Toura 17 allowing you to drain the whole boat from the front of desired. The first gen Evos has a drain plug on either end of the ski and wasnt a big issue to drain, small price to pay for the compartmentalisation of a potential flood.

Spot on ,the bulkheads that I picture are fully sealed but you can still have passage around them for cables etc ,it would not be hard to do and it would make your vessel a whole lot safer
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Re: Another heads up re. closing rear hatches

Postby shane » 22 Feb 2018, 09:51

A lot of yacht/boat bulkheads get filled with foam anyway as you don't have to rely on the bulkhead staying watertight. A basic can of polyurethane expanding foam from Bunnings etc will do the job and not absorb moisture. Sheath any drain pathways, rudder lines etc before inserting and then cover over or place a bulkhead wall if extra protection is needed.
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Re: Another heads up re. closing rear hatches

Postby happyas » 23 Feb 2018, 21:44

A remounting "class" was held at the Boronia pool a few years ago. I took my Evo 465 along. The main hatch seals weren't sealing properly so it ended up with a quantity of wet stuff on the inside. Eoin (Sea Sherpa) was enjoying himself flipping and remounting this yak. With the water inside it still remained horizontal. I assume that this is because of the buoyancy front and back with the bulkheads and the sandwiched buoyancy in the floor. The yak has a notice on it describing that it conforms to South African standards at the time of manufacture. I bet the E bay specials don't have any.
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Re: Another heads up re. closing rear hatches

Postby Jacko » 23 Feb 2018, 23:07

The new model Hobie outbacks come with foam packing inside the hull which my 2009 model didn't have.
I am told it is because of a change to the US coast guard requirements.
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