16 February 2009

SHOP: kayak mods_ retrofitting a ruddered kayak with a skeg

My SeaBird Designs kayak came with a rudder.
While probably a faster proposition for the racer a rudder in my opinion hinders good sea kayaks. I have paddled the kayak for a while now and always with its rudder stored on deck. The kayak does weathercock slightly.
In winds of 15 knots or stronger some effort is needed to edge the boat and use corrective strokes to keep it from turning into the wind.
The rudder has been removed and I have embarked into the daunting task of fabricating my own adjustable skeg.
Pricing a ready made kit from a local kayak manufacturer made me think that I can probably make a better one possibly cheaper.
Greg Schwarz has been my inspiration and his work is truly outstanding and after some consultation with him I decided that it must be done.

The trickiest part was sourcing high quality housing for the stainless steel wire/cable needed to adjust the skeg.
I found what I needed at an industrial hose supplier. The exact product is a high density polyethylene hose used for compressed air. The fitting for the hose is brass and has a neat "olive" to securely attach the hose to the skeg box.
The next step was to decide what shape and what size I wanted my skeg.

The skeg does not need to be very large and a sloped triangular one was going to be the least obtrusive one inside the rear hatch. I cut a piece of "smoke" colored 5 mm tick polycarbonate (Lexan®) to the slightly oversized shape of my desired skeg. Note the slightly oversized; we will come back to that later.

I waxed up the skeg with mould release wax and placed it on a smooth flat surface. Mixed up some epoxy and tinted it with black die: I don't like the look of semi transparent fiberglass. I used 2 layers of double bias cloth (available at most marine chandleries) and draped it neatly over the skeg.

top half ready, bottom is freshly laid
Once the resin hardened enough (10 hrs approx) I trimmed the excess cloth away with scissors and left a flange of about 2 cm. I repeated the same operation by flipping the skeg and making the second half of the skeg box. The two sides were flat and matched well.

I roughed up the flange surface with coarse sandpaper to create a good mechanical bond. This time I mixed up some epoxy (tinted again with black) and some microfibre filler (extender) to create a thicker glue that would not run. I joined the two skeg box halves allowing for a slightly wider gap at the bottom/entrance of the box to create a slight taper.

the two halves are joined

the bottom of the box was separated slightly to create a taper
The joint was filleted with the tick epoxy paste to create a strong joint line.
Once the joint cured the excess fibreglass flange was cut away and the ridge line made smooth with sandpaper.
A slot was cut to accomodate the brass housing fitting.
The fitting was fibreglassed into the slot with epoxy paste.

slot cut into skeg box
fitting before fibreglassing
fitting with fibreglas and resin
The skeg pivots on a stainless steel 5mm bolt secured with epoxy in the skeg box. A washers was cut out of nylon (or polyethylene) for each side of the skeg to prevent friction between blade and box.
cutting the washer
washers in place, excess bolt still to be cut
A slot was cut into the skeg blade to allow the skeg to be attached/removed without undoing the bolt.

The skeg wire was attached directly to the polycarbonate blade. A hole was drilled into the blade, a slot cut for the cable, the cable end was frayed a bit to ensure a better grip for the resin.The cable was resined in with epoxy paste and a laid on baking paper to create a smooth surface. The excess resin was trimmed once cured.
cable before resin
resin before baking paper
skeg dimensions (in mm, sorry metric only) click on image for larger view
The skeg is controlled by a stainless steel wire.
A control box with a knob attached to the wire was fabricated.
I used a piece of PVC conduit to shape a plug for my control box.
I cut the PVC pipe in half and after heating it gently on a flame I pushed it into a “U” shaped section.

I used West System 105 resin, 207 hardener (UV stabilized) to impregnate some carbon weave cloth.
Draped the resin rich cloth over my plug and overlaid it with cling wrap (Glad Wrap®) to prevent it sticking to the two blocks of wood keeping close shape to the sides of the cloth/plug.The box once cured needed end “walls”. I cut a small section of plastic and used it to “dam” the ends.
control box with ends in place
A section of the deck had to be cut out to have the control box recessed flush with only the knob slightly protruding.
Would you believe that after all that careful measurement and attention I cut and installed the skeg control box in the wrong position?
I took great care to make sure it will be out of my legs and knees' way but forgot to allow for the cable that would protrude past the box.
And of all places I did align it perfectly with one of the deck fittings.
The cable would run into the fitting!
After much cursing (you can imagine) I had to cut out the carbon box, clean up the resin and repair the massive hole left by the box. A new box was fabricated and repositioned.
The deck was repaired (I kept the section of deck that was cut out) and the gap left by the cutting blade filled with color matched gel coat.
skeg control knob (slider)
The control knob was fabricated from a piece of clear polycarbonate.
The knob was shaped to fit neatly inside the box and a hole drilled at the base to allow the sleeve to fit through.
The sleeve is drilled to allow a bolt (or grub screw) pinch the cable and keep it in the desired position.
The whole assembly has to run smooth and care must be taken to ensure that there are no bends where the sleeve runs inside the housing or a jam will occur.
control knob secured onto the brass sleeve.
The skeg cable runs inside the housing until it reaches the control box.
Here it enters a stiffer tube (stainless steel is desirable, brass will do) that would act as a sleeve.
The sleeve has to fit tightly around the cable and still be able to fit inside the polyethylene housing. The stainless steel cable is never exposed and therefore the chance of kinking the cable is reduced.
gel coat repair still to be sanded and buffed
skeg box view inside under the deck
It was time to assemble the skeg blade into the box.
You should end up with the blade well inside the box allowing trimming for the hull thickness and curve of stern keel line.

Once I had my parts ready it was time to prepare the hull for cutting.
This is the most critical part.
Measure twice, cut once! (yeah right...:-)
A perfect centre line is needed along the keel.
I selected and area as close as possible to the stern of the kayak but not too far for being able to reach from the hole of the rear hatch. I would need to work through that hole and be able to glass the skeg into place!
I masked the area with masking tape and draw lines on it to have a very visible cutting line.

masking and marking
checking for gap width
Once I was positively sure that all was good I fired up the Dremel®.
You will need a high speed cut off wheel. Wear a mask and goggles.
I cut less than needed and enlarged the hole slightly as required to fit the skeg box.
I managed to cut away a very tight fit and my skeg box had a gap of only 1 mm in places.

the scary part
The box fitted well and with the blade in place I made sure it would not protrude once trimmed.

skeg box before glassing
The skeg box was then perfectly aligned vertically in the kayak
A spirit level helps.
I removed the skeg blade and inserted a piece of wood the width of the box protruding about ½ meter.
I used that to align the skeg box.
The skeg box was then glassed into place with epoxy paste first (to create a watertight seal) and fiberglass tape later for strength.
Once cured I trimmed off the excess of the skeg box. A flush finish is desirable.

I masked a small frame around the box, sanded it and applied some West System 105/207 epoxy since my hull is clear and I wanted to have a non visible joint line. I did two applications for wear abrasion.

skeg blade retracted

pivot point
the skeg fully extended
skeg box view inside hull

housing attached to skeg box.
Loop/guard of fibreglass to prevent damage to housing when loading kayak with camping equipment

I hope I have not bored you with my account of retrofitting a kayak with a skeg.
I also hope that I have not omitted something and made the instructions not clear enough.
Feel free to comment and I might try to amend/update the document.

12 February 2009

Made locally

As the economic downturn worsens more people seem to get upset by imported goods.
I noticed some bitter comments on paddling.net when there was mentions of Confluence (group of companies including Wilderness System kayaks) moving most of it's manufacturing to China.
Some American folk were up in arms.
Obviously they were concerned about job losses.

A very similar sentiment seems to pervade locally with some sea kayak manufacturers and paddlers.
Some believe that buying a kayak that is imported is very bad form thus not supporting the local manufacturers.
I seem to have infuriated a few contributors of an Australian forum when I commented on my Chinese made kayak and it's virtues.

The kayak in question is made to be very light and strong with cutting edge technology but does not come with the expensive price tag of one similar made in a Western country (no such technology available yet in Australia).
I have been accused of supporting a government that abuses human rights (China) and that my kayak is the product of exploitation.

In reply to those accusations I have to comment that my view on a kayak made in China is:
1) why it's OK to be using just about every single electronic product made in China but not a kayak?
2) why is it OK to be clothed head to toe by cheap Chinese rags and shoes, our houses furnished by Asian goods and our cars predominantly made with Asian components but it's not OK to paddle something as simple as a kayak?

To the accusation of me supporting an economy that has been abusing the worker I have to say:
Chinese workers are better off with us buying their products than not.
As one forum contributor that has been importing goods from China pointed out: " ..for the last 13 years my supplier's standards of a workplace have improved dramatically, and admittedly not to Australian standard, but the factory worker today has a much better environment than 10 years ago..."
I believe that by Western companies outsourcing to China and creating a strong economy there it has helped the Chinese community immensely.
But how is "letting" our work being sent to China help Australia?

We live in a global economy and despite the insular mentality of some folks we can not sustain ourselves alone.
We import goods.
So, if our die hard traditional industry can not compete with the prices of imported goods it's time to switch gears.
No point in continuing manufacturing in a traditional style just because it has been done for decades.
Kayaks for example take a lot of "man hours" to build. Somebody has to manually handle the fabrics and the resin to construct a hull and deck.
A lot of time goes into assembling and finishing one off.
It requires a lot of labor and labour is cheap in China. So why insist on trying to compete with a labor force that is cheaper in Asia. Why does not want anybody set up a manufacturing plant of goods that requires unskilled labor here in Australia? because economically does not make sense. The locally made product would be too expensive and woud not sell too well, unless it is so much better then the imported one.
Please note the "unskilled labor" factor.
If the product would require highly qualified and trained personnel than things are different but for simple tasks Australians are wasted.
Australians are ingenious, talented designers, great inventors and skilled managers. China does not have those traits.
Let's capitalize on that. Create the work that nobody can touch: skills, know-how and expertise.

So, I will probably continue to buy Chinese products because they are substantially cheaper than other ones. Money does not grow on trees for me :-)
Just like my PC and laptop are Chinese made so one of my kayaks can be too (I have some Canadian and some British ones too and in the past I had New Zealand made ones).
I will probably buy high end items that require strict quality control and reliability made locally (or USA or Europe).
My EPIRB is one of them since my life might depend on it one day.

09 February 2009

Myths about carbon/Kevlar clear coat kayak hulls

On the weekend paddle, in a pod of 7 kayaks there were 4 with a clear coat carbon/Kevlar hull.
It was interesting to see so many different kayaks all finished with that magically looking cloth.
That made me think of some recent comments I have come across some posts on kayak forums: "...clear coat finish is not suitable for Australian conditions..."
My experience with several kayaks of mine in clear coat finish has been an eye opener on the subject.
While very attractive some clear coats can have limitations.
It is at times softer than gel coat, but not always.
Some clear coated kayaks are finished in vinylester resin while the more abrasion resistant ones, with a finish harder then gel coat, seem to be finished in epoxy.
Vinylester is designed for laying-up kayaks but at the same time offers decent UV protection therefore used as clear coat on a hull.
Unfortunately vinylester is not as abrasion resistant as gel coat and therefore will abrade faster than a traditionally finished hull.
I had one kayak that abraded prematurely and somehow initially I was very disappointed.
After some research I discovered literature from West System epoxy where a special UV resistant hardener was offered (#207).
I proceeded to repair my worn hull with a flash coat of epoxy 105/207.
The hull turned out really nice and shiny and I was happy with my repair.
The hull was now actually more abrasion resistant than standard gel coat.
Epoxy wears harder than gel coat and is way easier to apply.
Epoxy gives you a very long working time before it set off to harden.
It cures extremely shiny and no sanding or buffing is necessary.
Since the finish is transparent you can add a layer of fibreglass cloth (as you would in a keel strip) and the job would be barely noticeable.
You can maintain the shiny look for longer than on a gel coat boat.
Any surface scratches are easily buffed out.
However if your intended paddling environment will see you trashing your kayak on rocks, do seal launches off rocky shelves or you might envision holing your hull than perhaps a gel coat finish will allow you to perform a repair that cosmetically would be very hard (at times impossible) to achieve in clear coat.
So, for most common "mortal paddlers" (majority of kayakers) a clear coat finish is just fine.
Be prepared to maybe touch up that initial wear with epoxy and maybe add a keel strip but you will be able to have your hull shiny for longer.
In saying that I have worked on a few gel coat kayaks and with a bit of patience and the right gel coat color the repair became invisible. Matching the "color" on clear coat is not an issue: clear matches any color :-)
Go ahead, if you can afford it, have your next kayak in clear coat.
It certainly will not be mistaken for a plastic one.
But "vanity" has its price...

06 February 2009

BassMania at MEI

MEI has secured the screening of the premiere of BassMania.
Matt&Matt from the Wet Dreamers will present BassMania, a one-only show at MEI Head Quarters on Thu 12FEB.
The limited tickets were sold within hours and the show is promised to be a hoot.

03 February 2009

Snowy Mountains backpacking trip JAN09

It has been a few years since I have walked in the Australian Alps, not since the great bushfires.
I was concerned that one of my favourite destination has changed so much to make it unrecognizable.
The fires have effected the snowgum forests north of Schling Pass and the once lush groves of weather twisted trees are now just a place of ghostly greying trunks.
I will never be able to see those places in its full glory since the recovery will take longer than my life.
The few spots remaining where the fire did not singe everything are a real welcome.

The areas above tree line are however still in pretty good shape.
As long as you have confidence in your tent camping up high offers fantastic views and even those afternoon storms are enjoyable.

The flowers were blooming and covering entire fields.

Eventually the weather turned and the wind and clouds set in.

more images at www.flickr.com/gnarlydog

02 February 2009