31 January 2012

SHOP: repairing a leaky hatch

We all love a sea kayak with dry hatches but rarely that is the case.
After owning numerous kayaks I only had two that had consistently dry hatches.
Kayak hatches leak for a lot of reasons: poor design and materials seems to be the most common but often even a great hatch design can leak on one boat and be dry on the next one.
So what causes hatches to leak?
Hatch cover_ VCP

I found that the type of hatches using a neoprene cover seal under a fiberglass lid work well when new but after a few years deteriorate and start to let water in.
Of course, let's not forget that  most kayak hatches will remain dry if the kayak is used in calm conditions and the water does not reach the lid.
Some hatches seal extremely well and seem totally leak proof, to then let water in when the kayak is inverted (rolled) on a hot day. Drilling a very small hole into the bulkhead usually solves the problem because it helps to equalize the expanding and contracting air when heated and cooled during rolling.
As air heats up in the sun it expands and when the kayak is suddenly inverted into the cold water, the cooling effect contracts the air inside the hatch resulting in suction. The lid might seal enough to prevent water splashes intrude the hatch space, when paddled right side up, but not enough to prevent the force of suction when submerged (inverted)
But what to do when you know that you have a very good seal with the lid (and there is a breather hole to let the expanding/contracting air in-out) and your hatch area is wet after even a non rolling kayak session?
I had a few cases of hatch covers rims leaking.

The (usually) black rim is cemented to the deck of the kayak by a bonding agent. In quality boats that happens to be an epoxy type glue and in some other kayaks is just simple "goop", ranging from silicon to polyurethane.
Either epoxy type glue or goop bonding can perform the task of keeping those rims attached as long as there is a solid continuous bead around the whole perimeter of the rim.
It does not matter how expensive my kayaks are and from what reputable brand; leaking hatch rims are not uncommon.
I have removed a badly sealed rim: I found the caulking under the rim made very poor contact and looked like the factory worker forgot to press-in the rim firmly enough against the deck. I cleaned up the bad silicon and re-seated the rim with polyurethane.
In an other case the epoxy glue did not make it all around the rim leaving a section without a proper seal. I could not remove the rim (the bond is seriously strong) but I mixed-up some epoxy glue of my own and poured/forced it into the section where there was none.

Last but no least: even with the rim seated well and the lid being positively waterproof in one case a hatch was still leaking despite the best efforts in finding the problem.
On a friend's kayak a hairline crack was eventually noticed on the gelcoat close to the rim after doing the test (below). A bit of poking revealed that the gel coat was all there was keeping the water out. There was a large air bubble in the lay-up where the reputable manufacturer did not fill; just fiber and no resin, letting water seep in.

The repair involved him removing away all the gelcoat above the void, remove loose fibers and clean the area with acetone.
Several solid layers of new cloth and epoxy were laid (inside the hatch) over the repair. Gelcoat had to be matched to the existing color to make the repair invisible.

While performing this repair on the deck the cable for the skeg needed some attention too. It used to be very sticky when trying to deploy it: the housing would flex and bind under pressure. Glassing a long unsecured section of the cable housing to the under deck solved the poor performance.

While some hatch lids will seal really well others will only seal sometimes.
I found that the kayaks with the new Kajak-Sport lids (dual density) work well in winter but poorly in summer. What gives?
I have the mandatory vent holes in the bulkheads but when I go for a rolling session in the summer warm waters it seems that the new lids (softer rubber on the edge, stiff plastic in the center) leak about a cup after an hour or so. I am not the only person that has this problem since others have revealed me to experience the same.

in this video light vaccum was applied to test if water would seep past the lid's lip

A friend of mine solved his case with the dealer promptly shipping him the older style round lids that are made entirely from soft rubber (non floating type): now they seals 100%.
Worth mentioning that after precise measurements of the roundness of the hatch rim, he found it to be 1mm out; would that effect the sealing of the dual density hatches?
However to solve my problem, I am unsure if I will be able to source the old large oval Kajak-Sport lid to address my summer paddling leaks.

PS: The key to these repairs was placing a small waterproof camera inside the hatch and film the source of the leak. I recommend trying it if your hatches are suspect.

PS AUG2012 If you are not happy with the performance of your hatch covers have a look at Sea-Lect Design ones. Review here

24 January 2012

VIDEO: Rollabout

A short video on Greenland rolling in South-East Queensland starring Stika and Toddy.

This video is under license from Geggamoja Industries

Camera and rolling: Greg and Moira Schwarz (additional footage by Tess Dodd)
Paddles: Greg Schwarz custom laminated hollow-core Western Red Cedar


17 January 2012

VIDEO: sailing with Flat Earth Code ZERO kayak sail


After some initial testing in November with Flat Earth Code ZERO sea kayak sail, over the Xmas break the weather presented some good opportunities for sailing in winds of max 20-25 knots.
I mounted the Code Zero onto a skegged kayak of British style design and despite finding that the kayak does lee cock at low speeds it was easy to sail because the hull has a fair amount of initial stability.
In saying that, any kayak of mine once is underway with a sail I find that she increases its stability: the sail seems to prevent the port to starboard wobbles in a textured sea.
The slightly increased surface area of the Code ZERO was noticeable and the kayak picked up more speed over wind waves in lighter breezes (10 knots).
In higher winds there were moments when the kayak really started to hum and the deployed skeg was “singing” when surfed down the waves.

VIDEO: select 720p if you have fast Internet connection
Eventually, on the second day of sailing, the wind became a bit too strong for me to handle the full sized sail; it was time to try the reefing feature (in the video at 2:25).
Again, I had no opportunity this time to test the kayak’s speed with hard facts, but I didn’t think that the kayak was travelling through the water any slower than with the full sail.
Not sure why this perceived speed but could it be that I was reaching hull speed with either size sail?  I understand that a kayak can only travel so fast at a given range of propulsion; to go any faster much more energy is needed and maybe the sail at full size could not bring the hull on a plane?
I would like to hear if my rationale makes sense.

Disclaimer: Flat Earth Sails has supplied me with this test Code ZERO sail. Gnarlydog News product review policy can be viewed here


12 January 2012

Gnarlydog News product review policy

After a recent post on Gnarlydog News where some commentators questioned my integrity with my reviews on this blog as true independent non commercial articles I think it's time that I clearly explain my policy.
"Mike" accused me (in the comments section here) of writing articles for this blog as commissioned paid reviews.
While GDN has now passed the 200th post with a variety of articles spanning from simple images, videos, observations, opinion and criticism I also include reviews of gear that I use.
I would like to stress the point here on the "gear that I use".
As the popularity of GDN increased over the years readership now reaches in hundreds of page loads per day. Some manufactures regularly visit my pages for ideas and to see what does not work for me; I guess, with my posts sometimes I offer an indirect feedback to them.
At the same time some manufacturers also notice my efforts in describing and researching a product, which I often accompany with non-stock images and videos of mine.
I have been approached several times by non-kayak related companies asking me to review some of their goods. After a brief discussion with the business interested in my blog I realized that they were after a favorable  review of products that do not interest me personally. I politely decline their offer explaining that I only would consider items that I would personally use.
I also have been asked to promote businesses and events but, since I was not personally involved with those, I declined again.
Occasionally there is a manufacturer that offers me a product that I would like to try. I engage with the supplier and analyze the product before I commit and ask them to send me a sample. I understand that small businesses are on a tight budget and can not afford to simply send samples to anybody therefore, if the product that they offer appears to be of a style and design that does not agree with my philosophy (I like things simple, compact and sturdy) I again decline their offer.
Now, there are some products that I really like and occasionally I will ask the manufacturer to supply me with a sample. Often they decline my request.
There are cases too where the manufacturer engages in a healthy conversation with me about the design of their product before they offer me any samples. This is the case with Northern Light Paddles.

Sunset paddling_3_c

Paul had a lengthy exchange of emails with me before he finally decided to take the risk to supply me with his paddles. He knew that if I didn't find his paddles to my liking there was a risk I would give them an unfavorable review. Just like with Flat Earth Kayak sails, where initially there were some minor design flaws, the conversation with Mick was open. He looked at my findings and he improved his product.
I now use Flat Earth Sails exclusively finding them superior to my design.
Sailing into the sunset

With Northern Light paddles I have found a product that is unique and fits my needs very well.
At no stage was I ever paid to review any product, never have.
I will accept products for review as well as I will review items that I buy in a retail shop, full price.
I also occasionally review items that are loaned to me but only if I personally I am interested in.
So, if you, the reader, feel that I have breached your trust with the honesty in my reviews, I ask you to stop reading this blog.
On the other hand I am sure that many will find my policy acceptable to be still called independent non-commercial review.


10 January 2012

SHOP: sail mast base on Valley kayak

Following Jim's set up for a sail mast base on a Valley sea kayak utilizing the compass recess, I want to detail here a fitting that requires no additional holes drilled to the deck.
On the Valley decks there is usually a fitting that holds bungee cords in place typically used for stowing split paddles on the foredeck.
I have a hard time placing a paddle under those bungee cords and prefer the paddle parks.
Actually these days I prefer to carry a Greenland style storm paddle on the rear deck.
So, that fitting on the deck is the perfect anchor for a sail mast base.

Valley deck fitting recess

I remove the fitting and grease up the cavity/recess with several layers of mold release. I find that a final layer of PVA mold release works best before I fill the cavity with epoxy paste (I mix epoxy, microfibre and filler to the consistency of peanut butter).

filling cavity

Working-in the paste ensures that there are no air bubbles. I build the base high sitting proud of the deck.

filling cavity_2

glass layer

I add a layer or two of fibreglass to keep the epoxy paste from running too much

flattening top

A final layer of kitchen cling wrap to be able to shape the paste into a neat bump and I place a square object to create a flat surface.
Once the epoxy cures overnight I pry the fitting out of the mold and smooth it with sandpaper. There will be a dimple where the original bolt held the deck fitting: that's where I drill through the sail base and countersink the top to accept a new longer bolt of the same thread pitch (M6, metric). I cover the mast base with a layer of carbon (just for looks) and UV stable epoxy (West System 105/207). I make sure I push the countersunk area down to maintain the recess for the bolt's head. Often I place a small greased-up plastic cap just of the right size with a tiny weight on it to keep the wet carbon cloth in place.
Once cured, I drill through the last thin carbon layer to insert the central bolt.

Central bolt

The base of the mast is carefully positioned onto the carbon base and holes drilled to accept the fasteners.
A recess is needed for the nuts underside making sure they clear the deck.


I use M4 stainless steel Allen key button head fasteners and nylock nuts.

fastened to deck

The plastic red base is bolted to the carbon base which in term is secured to the original Valley factory anchor on deck.
The base does not rotate because of the recess. No holes were drilled into the deck for the mast base but I still needed to create some recessed anchors for the mast stays.
I also reinforced the underdeck area with a rib fabricated from foam-core, fibreglass, carbon and epoxy under the mast base since the deck is too flexible.
However I discovered that this location is not ideal on all Valley decks. The deck fitting is not located in the same place on the different model Valleys. One of my Valley kayaks tends to leecock when paddled at slow speeds.
Just like when I used to windsurf, where I tilted the mast back to turn into the wind, I have now tilted the mast of my Flat Earth Sail backwards to give the kayak a neutral direction in beam winds. 
Video of sailing with this kayak and the new Code ZERO Flat Earth Sail coming soon.


05 January 2012

REVIEW: Northern Light Aleut carbon sectional paddle

Paul from Northern Light Paddles sent me a while ago a couple of Aleut sectional carbon paddles. He asked me to test them in the surf and report of my findings.

I have previously used the Aleut several times in flat seas with a maximum of a 1' wind waves but on NewYear’s Eve I took it to a familiar surfing place. Finally I had the opportunity to give the Aleut paddle a go in the rough water.

Surfing Kadzait_2_r

The waves were small but the tidal flow was still running in at a decent pace which made hard work to paddle out and catch a couple of good runners. I was in a new kayak and I was still finding the particular traits of that rather stable British boat which paddles very differently than my hard chined low volume Zegul520.

The Aleut feels different than my Greenland Northern Light paddle and also different than my Western Red Cedar Vanstix. At a close inspection I notice that “back side” is not really flat (there is a general consensus that the flat side of the paddle is the non power face, but nobody knows for sure how the Aleuts used to orient their paddles) . On the blade, closer to the loom, the surface is actually concave creating a gentle spoon. Not as drastic as on a true wing paddle the NLP Aleut does however favour a wing style motion to get the most efficient stroke.

Aleut concave_gdn
"back side" of the blade

With a Greenland paddle I tend to cant the blade and create “lift” and a clean quiet stroke; with the NLP Aleut I don’t cant.
I tried paddling both sides: power face and back side; interestingly enough the paddle works both ways. With the ridged side as powerface the paddle feels stable with no flutter but I found that my stroke was not totally silent; I was introducing air in my catch. The paddle is easy to use, somehow easier than the GP if a beginner had to use it for the first time since no canting is required.
Paul suggested that I try also the backside as powerface.
Reluctantly I inverted the paddle assuming it will flutter similarly to my Vanstix (not designed to be paddled inverted). Initially the paddle felt a bit odd as it didn’t have the same gentle entry of a canted GP. I adjusted my stroke to a more square catch and pushed diagonally outwards, away from the hull. I didn’t measure my speed with a GPS (I am a low-tech paddler) but I am sure there was more resistance at the blade than with a GP. And there should be: the concave shape of the blade prevents water from “spilling” and anchors the blade firmly into the water. There is also more surface on that blade resulting in more power generated for the same stroke. If I maintained the same cadence as with a GP I felt that I was gaining more ground err.. water.
Theoretically this Aleut paddle would suit surfing better where powerful strokes are needed to quickly accelerate the kayak down the face of the wave.
I guess it worked. Watch the video:

select 360P if you have slow Internet connection
Otherwise the Aleut offered me the same amount of support that I like when bracing a broached kayak. Rolling was solid but I find that the GP sculls easier since it has finer edges and a lower cross-section profile. The Aleut is longer than my GP therefore presents more surface in the water. The loom is the same as on the GP (just longer): sectional, oval/squared-off and inserts into the blades in the same way utilizing stainless steel fasteners to secure the 3 sections.

Aleut joiner_gdn

Since the asymmetrical blade (from power face to back side) is also offset it acts as a cam in your hand. The power face sits easier in the hand and when the blade is inverted I had to grip the loom just a bit stronger. I find the shoulder transition between loom and blade gentle on the powerface side but when I use the paddle inverted it is more noticeable: the blade finishes more abruptly against my hand and the shoulder is sharper.
If I had to pick one paddle only I would prefer to own the GP as an all-round paddle and while I feel the Aleut offers more surface, it reminds more of a typical resistance of a Euro paddle.
I have been paddling traditional paddles for too long to be able to say with certainty that the Aleut would be an excellent transition paddle for somebody wanting to venture into the world of skinny paddles but fearing they lack power. For surf work maybe the Aleut could have an advantage but I honestly have to give it more time and testing before I can be sure of that.
I have been appointed as Australian East Coast ambassador for Northern Lights paddles. I have a selection of Greenland and Aleut sectional paddles to try. Feel free to contact me at gnarlydognews(at)gmail.com for a demo paddle.