Leaky Hatches Poll

[Dee Hall]

I disagree for many technical reasons, but I am sorry, but I don't have time to explain it now.

-Dee

[donperry]

On my boat there is a good chance sand will eventually lodge in a small diameter hole.

If I were to do this, I would locate the hole high on each bulkhead and make it large enough to accommodate a small duckbill (check) valve. It’s a replaceable item used on siphon-breaks for marine heads and usually available at marine supply stores. After it is seated in the bulkhead up to the molded flange it could be held in place by a quarter-sized piece of Gore-Tex bonded around the edges to the bulkhead. This would make it possible for pressure to increase in the chambers but not decrease.

…A naval seal, if you will.

Don

[Brian Nystrom]

...is that it only allows flow one way. For a breather to be effective, it needs to work in both directions, since the pressure in the sealed compartments can be negative (warm boat placed in cold water) or positive (boat removed from cold water and warming in the sun).

Some folks have gone the route of putting Gore-Tex patches over breather holes, which theoretically is an interesting idea. In practice, the tiny breather holes are not a problem. I have yet to have one clog in the 3+ years I've been using them.

BTW, I have put a hole in a boat with breather holes in the bulkheads. In an hour plus of paddling afterward (I didn't realize the hull was holed), aproximately two gallons of water entered the compartment. I'm not sure what that means, but it doesn't seem as if the breather had much, if any, detrimental effect.

[Brian Nystrom]

>Cracked Rims:

>It was interesting to note that cracked rims were more

>prevelent on boats with thin flexable decks. It could be

>that the cracks are a result of flexing caused by internal

>and/or external pressure.

I suspect that you're correct, though I've seen such cracks on boats with relatively stiff decks.

>Breather Holes:

>Although I was initially impressed by the reasoning to put

>breather holes in bulkheads, my current feeling is that it

>defeats the safety feature of a watertight chamber. For

>sure, a small breather hole will equalize the pressure.

>But, if you hole your boat, a breather hole will enable a

>watertight chamber to quickly flood with water. Although

>hatch covers are relatively easy to open from the outside,

>they are almost impossable to dislodge under internal

>pressure. IMHO a more prudent (costly) alternative is to

>have a second set of covers with breather holes. The covers

>would only be used for transport or storage.

>Example: Imagine a cup of coffee with or without a breather

>hole in the lid!

I understand your concern, but my experience doesn't back it up. When I holed my Silhouette, relatively little water entered the compartment, despite the breather hole. From a practical standpoint, it seems to me that the risk of damage to the boat from no breathers is greater than the risk of leakage. Imploded decks and burst seams can and do happen. The fact that they're not more common is probably due to the fact that most boats aren't that well sealed.

Thinking about it, I wonder if some of the split hatch rings may be caused by pressure problems?

[MattH]

After seeing what everyone else paddles, I'm emabarrassed to admit to the boats I own, but hey, they get me out there.

96 Aquaterra Sea Lion: Dry as a bone.

96 WS Sealutions II: Rear leaks bad. Especially after rolling sessions.

Ancient Klepper Aerius II: What hatches?

[Richard N]

>I disagree for many technical reasons, but I am sorry, but I don't have time to explain it now.

>

>-Dee

Dee,

Don't try to explain it.

Please take a few minutes to perform this very simple home experiment.

Estimated time to complete: 20 minutes

Supplies needed:

- - Very large (to go) coffee cup with lid from "Dunkin Donuts"

- - "Duck" tape.

- - Two or three small butter knives (metal)

- - Magic Marker

1. Using the Magic Marker, draw a straight line across the outside bottom of the cup through the center bisecting it into two equal sections. Draw another line perpendicular to the first dividing the bottom into quarters.

2. Place the cup upside down on a work surface.

Using THREE of the points identified by the above markings along the circumference of the bottom, draw three straight lines (outside) to the top of the cup.

3. Tape two butter knives along the inside surface of the cup. Placement should be along the center (keel) line. You may need to face them in the same directions to balance the load.

4. Secure the lid on to the cup being careful to line up the drinking opening with the center (keel) line and the knives taped on the inside.

5. Put a small piece of tape on the breather hole (vent) located on the lid and another piece of tape on the drinking opening.

The above represents a kayak with a sealed compartment.

Knives are along the keel line.

The other two lines represent the water line of a boat.

Note: Depending on the weight of the knives, you may need to reposition the knives and/or add a third knife to have the water lines along the cup line up with the surface of the water.

6. Fill your kitchen sink with water.

7. Place the above sealed container in the water.

Question 1: After 5 minutes, how much water enters the cup?

8. Remove tape from drinking opening making sure the tab does not block the opening. Place the container into the water.

Question 2: After 5 minutes, how much water entered the cup?

9. Remove the second piece of tape from the breather hole.

Make sure the breather hole (vent) is not plugged.

Place the container into the water.

Question 3: After 5 minutes, how much water entered the cup?

Question 4: Was buoyancy and stability of the cup effected?

Dee, we value your objectivity and interest in breather holes and are anxiously waiting for you to post the results of this very simple experiment.

The answers to questions 1-4 should settle the controversy.

For technical explanations, you may study the following:

Boyle's Law

Archimedes' Principle

Richard

Living to learn.

Romany White, Blue trim

[Guest guest]

Ya' know what I think of all yer' breather hole talk......never mind...

[Brian Nystrom]

...who is having trouble posting and asked me to do this for her:

Richard,

I am being very restrained about your assumptions of my knowledge of physics and fluid mechanics, compressible and incompressible.

-Dee

[djlewis]

OK, I'll speak for Diamante owners, who are probably too embarassed to show themsleves in a public discussion of leaking hatches.

Diamante hatches are only slightly drier closed than open. Seriously, after half an hour of rolling practice, there will be a quart or two of water in them. Just paddling in anything but flat water will put a noticable load of water in them after a couple of hours. I carry two sponges and have developed my sponging technique to a high art. (Should I offer a class in it?)

There is a partial solution -- strap the covers down so tight that you can barely release the buckles on the water, and cannot rebuckle them without another boat to support you.

I have seen one better solution claimed, but have not installed it myself. Permanently affix a small but somewhat thick (maybe 1") piece of not-too-hard foam either to the underside of the buckle or to the top of the hatch under the buckle. Then, when securing the straps, make sure to pull them tight enough to compress the foam. The extra pressure allegedly improves the seal a lot, though I'm skeptical that it's anywhere near perfect.

--David

[Richard N]

<-Dee

Dee:

No assumptions were implied or intended other than the obvious results of a very simple and straight forward experiment.

Also, for the benefit of all who rely on this board for useful information, we should restrict our writings to objective communications rather than emotional and unhelpful personal comments.

Any follow-up you may have to this post should be send to

my personal Email address; brucemedi@aol.com.

I will not lower myself to be sucked into a worthless

(to use your language) "p _ _ _ _ _ g contest".

Richard

Living to learn.

Romany White, Blue trim

[jeffcasey]

Oh, ok....David has shamed us Diamante owners into showing our faces. As a physicist, I was actually trying to stay off of this thread, due to the noise level down below....

As David pointed out, the hatch covers on the Diamante are pretty much useful for keeping the drybags from coming out of the hatch. What? You don't use drybags for your lunch & misc gear? You better if you paddle a Diamante.

I've tried the "press-like-the-dickens" solution, and the "goo-it-up-with-extra-RTV" solution, with minor improvements. I rationalize that since I have a hatch full of drybags (and actually real float bags for safety, but I'd do that with the unused space in any kayak), I don't care. However, if anybody has a decent solution, I might start caring.

Advantage: who needs breather holes!

[Guest guest]

P & H Vela

Kayaksport hatches.

All three dry when "double sealed".

Even after extensive rolling (and failed!) rolling practice.

Rough water conditions as well.

Deb

[cmfos]

Yes indeedy, I have two stories that are kinda fun. The first was my introduction to some of the physics you folks are talking about down below. Last year in January, I'd come back from a nice tour of the waters up around Portsmouth NH. It was a cold cold day (probably 2F with no wind thankfully) and I was taking my Romany Explorer out for its maiden voyage. We had a nice tour and I drove back to Boston and lugged the boat up to my apartment, got cleaned up and then watched some TV. About 15 minutes later, I start hearing this high, keening, wailing sound. What the heck? I look at all my smoke alarms, look out the window to see if some cats are . . . doin' the nasty, I poke my head in the hall to see if something is wrong downstairs. then I realized that the sound was coming from the rear compartment of the Explorer. The cold air inside was starting to warm up, expand and start forcing it's way out around the hatch cover. Squeeeeeeekkkk! I laughed at myself for my foolishness at not coming to this realization sooner.

The second story is when my girlfriend and I were paddling in the Adirondacks last summer. We had some perishables that we wanted to keep for a couple of days so we packed them in dry ice, in a flexible cooler. I jammed the thing down into the rear compartment of my Avocet and continued packing the boats. A few minutes later, we both jumped up as the rear hatch cover popped up with a big WHUMPH! sound. I chuckled derisively to myself as i realized that the dry ice was sublimating away into CO2 gas and that this gas had blown the rear hatch. Ah, the vagaries of physics!

If only I had a blow hole

Jim

[Guest guest]

I would agree with Jill about the folks at Boreal. We stopped there last winter on the way back from Winter Carnaval in Quebec. They were truly pleased that we visited(Linda has an Ellesmere)and gave us a tour of the plastic boat factory. They also have a retail store with some amazing off season sale prices.How about a new Boreal spray skirt for about $25 US?

We will be there to cheer on Team Boreal Design at the Ice Canoe Races in a few weeks. This is some serious stuff on the water! Check out[http://www.goldiproductions.com/Pages/OAC/Programs/IceCanoe.html]

[Guest guest]

my quest doesn't really have a leakage problem.

those stickers are on there goooood.

[adelavega]

>As David pointed out, the hatch covers on the Diamante are

>pretty much useful for keeping the drybags from coming out

>of the hatch. What? You don't use drybags for your lunch &

>misc gear? You better if you paddle a Diamante.

>

>I've tried the "press-like-the-dickens" solution, and the

>"goo-it-up-with-extra-RTV" solution, with minor

>improvements. I rationalize that since I have a hatch full

>of drybags (and actually real float bags for safety, but I'd

>do that with the unused space in any kayak), I don't care.

>However, if anybody has a decent solution, I might start

>caring.

>

I've never seen a Diamante (or at least never looked closely

at the hatches), but if they're the buckle type, you might want

to try weather striping. The hatches on my Cheasapeake were

always bone dry, though they were nothing more than a bent

piece of plywood with two straps. The key was weatherstriping

glued to the underside of the hatch cover, that fit exactly

inside the opening, sealing it completely.

If this sounds workable for the Diamante, it could be the

solution to your problem... Of course, then you'll have to

deal with the breather hole issue ;-)

--Amy

[Guest guest]

The following is intended to summarize the results of the poll. There is no matrix of boat, hatch, dryness, etc. but I have attempted to summarize methods to insure and/or repair leaky hatches.

Don't assume that all leaks are due to poorly sealed hatches. Potential causes include, but are not limited to; the bow/stern toggle holes, bulkheads, recessed deck fittings, deck mounted gear, Skeg boxes or fittings, cracked or improperly sealed hatch rims, screws through the hull.

Leaky deck plates can be made watertight by wrapping tape in the O-ring grooves, under the O-ring. This creates a tighter fit, but it may necessitate lubricating the O-rings with silicone spray in order to reduce friction during installation. Use only SILICONE spray.

Improving hatch seals using; weatherstriping glued to the underside of the hatch cover, bungee loops around hatches (and can also function as attachment points for hatch tethers), double sealing (pushing the outer edge of the cover tight against the hatch ring), carefully trim the hatch cover flange in order to be able to double seal it, clean the hatch rings.

Boreal is cited for excellent customer service.

Breather holes: While support for these is less than unanimous the majority endorsed their usage. Suggesting a 1/32" to 1/64" drill (a thin wire/bicycle spoke) and locating holes an inch or so above the center of the bulkhead.

Diamante hatches are only slightly drier closed than open.

The quality of the seal has something to do with the size of the hatch cover.