Pakboats Materials and Components

Quite a few materials and components go into making the Pakboats, and we try hard to find just the right material for each application.

Aluminum Frames.

You might expect us to look for the stiffest aluminum material we could afford - and you would be wrong. There is no material that is stiff enough to resist damage if a canoe is pinned on a river, so we look for aluminum that will effectively resist taking permanent bends in normal use. But we want the material to bend before it breaks. And we want it to be pliable enough to straighten so parts can be repaired on the riverbank after a mishap. We think the aluminum material we are using has the right balance of stiffness and pliability.

If you will use your Pakboat in salt water, you want the boat frame to have good corrosion resistance. The aluminum alloy we use does, and in addition we are having all aluminum parts anodized. That keeps the frame looking nice, and it is more pleasant to work with it. It also helps prevent "frozen" connections in the longitudinal rods.

Hull Fabrics.

It will be no surprise that the bottom is exposed to a lot more abrasion than the sides. This means that we can use lighter materialfor the sides. The bottom needs abrasion resistant stuff. The abrasion resistance is in the coating, and the tear strength and tensile strength are in the woven fabirc. Besides keeping the fabric waterproof, the coating is there to protect the woven stuff so your boat will not fall apart. There is very little abrasion on the inside, so the inside coating is very thin, and the outside coating is much thicker.

Foam Pad.

PakCanoes are exposed to a lot more abrasion than the kayaks, and that is why we cover the bottoms with a closed cell foam pad between skin and frame. That eliminates pressure points and adds an amazing amount to the abrasion resistance. To avoid adding too much to the packed size, we use a 1/4 inch thick medium density closed cell polyethylene foam material.

Keel Strip.

The keel strip is there to increase abrasion resistance. Because the fabric rests directly against the keel, in the kayaks the fabric along the keel will sometimes be abraded betwen two hard surfaces, which increases abrasion quite a bit. The bottom fabric itself is very tough and does not need to be strengthened by the keel strip. It just needs to be protected. That is why our keel strip material is just PVC all the way through. There is no need to have fabric reinforcement in the keel strip.

Deck Material.

We use medium weight polyester material with a woven diamond shaped rip-stop pattern and polyurethane coating. This stuff is dimensionally stable so the deck will always have the same fit. It is also attractive looking and very strong. We use the same material in PakCanoe spray covers.

Inflatable Parts.

The inflatable parts are welded in a simple and efficient welding process. The catch is that the welded seams need to be very strong, so we need the right fabric. We use a medium weight nylon fabric laminated to a sturdy, but light polyurethane film. This way we get very strong and light inflatable parts. This is a big part of the reason Puffins are so much lighter than similar size inflatables.

Technology & Design

At Pakboats we believe that the best design for any given task is the simplest one that will perform well. Simple design helps keep cost and weight down, and it helps keep Pakboats easy to assemble. But excellent function for the intended use is our main concern. Since there are Pakboats for widely different uses, it should come as no surprise that structural design varies quite a bit. Here is an overview. You will find more detail in the description of each product.

- PakCanoe Design

- Puffin Design

- XT Design

All Pakboats are designed with a waterproof skin covering a framework of interlocking longitudinal rods and shaped cross ribs. On each side between skin and frame is an inflatable tube with multiple inflatable chambers for secure flotation. The inflatable tubes also act as built-in fenders, and by inflating the tubes, you add tension to the skin. The inflatable tubes are also an important safety feature. Placing a generous amount of flotation in any boat is an obvious benefit. We have gone further by placing the flotation carefully where it does most good. With flotation placed end-to-end along each side rescue situations become more manageable. Here is why:

- After a capsize there will be water in the boat. With the flotation placed in the sides, the boat cannot capsize again without submerging the flotation, so the boat is much more stable.

- Bringing the boat upright from an inverted position, the boat will at one point float on its side. The side flotation makes it float higher at that point, so it will scoop less water into the hull while you turn it upright.

We have found that avoiding direct contact between skin and frame makes a great difference in protecting the skin from damage, and we have taken advantage of this wherever possible. PakCanoes are built to for expeditions, and we have placed a closed cell foam pad on the bottom under the frame to protect the skin from abrasion. On remote wilderness rivers, abrasion is inevitable, so we have welded reinforcement strips to the PakCanoe skin under each longitudinal rod.

In Puffins and XTs we have protected the skin by extending the inflatable tubes below the chines. There is no foam floor because foam would add bulk to the packed boat, and the kayaks are less likely to be damaged by abrasion. But there is a heavy-duty keel strip factory installed on each boat.

New for 2009 is that deck supports are built into the decks themselves. This makes the kayak frames simpler, and it becomes easy to adapt each boat to one or two seat positions. Simply install the seat(s) where they need to be for ideal trim and make decks with cockpits to match the seat positions.

Puffin Design

Puffin Design

The Puffin Kayaks represent a new generation in folding boat design and draw on over 30 years of varied experience.

Three basic elements interact to form the Puffin's structure:

* The skin is the outside cover that "keeps the water out". It is made of woven synthetic fabric coated with PVC. A heavy duty fabric forms the boat bottom, and lighter fabric is used for the sides. Stress points are reinforced for years of trouble free use.

* The frame is made of anodized structural aluminum tubing with a combination of high strength and corrosion resistance.

* Between skin and frame in the sides are inflatable tubes that act as flotation and give tension to the skin. These relatively large diameter tubes also help stiffen the boat. To tolerate the working pressure, the tubes have a strong fabric outer surface laminated to durable polyurethane film to form air holding cells on each side of the kaykak.

Puffin seats are inflatable and made of high-grade polyurethane coated material. The seats have adjustable back rests and built-in lumbar support. They are very comfortable!

Puffins have extremely simple frames. There are only three longitudinal rods - two gunwales and a keel, and a number of cross ribs that connect the longitudinal rods. To make this work we had to develop a new way to give the boat longitudinal tension. This was done by placing a "hinge" in the keel. When the keel and stems are installed in the boat, the "hinge" is at an angle. As the cross members are installed, the keel gradually becomes straight and tensions the skin. Side to side tension is produced by inflating the air tubes.

Placing inflatable tubes along the sides in a kayak does more than provide light-weight structure. Puffins have much more flotation than other kayaks. And placing the flotation along the sides makes Puffins incredibly stable after a capsize. Two separate air cells on each side of the hull provide security in case a cell is punctured. Note: Inflatable boats have even more flotation, but their paddling performance is poor, and a similar size inflatable weighs about 50% more than a Puffin.

Puffin decks are attached with a strip of Velcro around the boat just below the gunwales. An aluminum cockpit rim provides support for a spray skirt. The separate deck makes it much easier to pack gear into the kayak. Simply remove the deck, load your gear into the boat, and reinstall the deck. If a piece of gear does not quite fit, let a little air our of the air tubes, stow the gear, and reinflate the tubes. (Make sure no sharp objects touch the inflatable parts.)

XT Design

Since the XTs are our newest kayaks, I will give you a quick tour of the design process. The real process took a couple of years - and countless sketches on napkins, with some computer simulation added for good measure.

To make a kayak like the XT, a completely new frame structure had to be invented. The challenge was to make a long and sleek folding kayak with excellent stiffness. In other folding kayaks, the designers often rely on a deck structure to give the hull enough depth to enhance stiffness. We wanted to be independent of the deck. The solution turned out to be 6" wide I-beams along each side of the hulls.

Conceptionally, adding I-beams is simple enough, but implementation was a challenge. The I-beams had to fold up and pack into a compact package, and they had to be rigid once assembled in the boat. That means that all the joints have to be absolutely solid, and the forces involved are considerable. A number of ideas were proposed and discarded until Ralph came up with the concept of attaching the locking system to each cross rib. Stainless steel pins fit into matching holes in the top and bottom joints of the I-beams and keep the joints solidly together. One pin is fixed to the top of each cross rib, and another to a lever that snaps into place against the cross rib. This locks I-beams and cross ribs together in a solid and lightweight frame.

Unlike other Pakboats where longitudinal skin tension is built gradually as the frame is assembled in the skin, XT frames are built outside the skin, so a new tensioning system was required. We tried and discarded ratchets and finally settled on a lever system built into both stems. The levers transfer tension to the I-beams and push against the ends of the kayak skin.

The kayak skin needed some work too. With the I-beam frame, we no longer have simple gunwales that can be inserted into channels. Instead, we wrap the top of each side of the skin over the gunwale and secure the sides to the frame with cord loops.

Tightening the skin sideways is a familiar operation. The XTs have inflatable tubes like the other Pakboats - the slimmer style that we have used in PakCanoes. Inflating the tubes makes the skin nice and tight. Not much new design work to do here - except that we tapered the ends of the tubes to get the sharp entry lines of a high-performance touring kayak.

The XT decks are very different from decks we used to have on the Puffins (but a simplified version of the new XT deck has migrated back to the Puffins for 2009). We wanted to have the XT decks solidly supported and at the same time be able to change seat positions freely so an XT could be used both solo and double. The solution turned out to be a deck support structure built into the deck itself. No part of the frame is intended to support the deck, so the hull can be completely open. The cockpits and seats can be placed without regard to any part of the frame. While we were at it, we made the cockpits longer to make it easy to get in and out of the XTs. To minimize assembly time, we wanted to leave part of the support structure as well as the back band and (optional) thigh straps permanently attached to the deck. This required adding a flap on each side under the deck fabric to attach accessories to.

XT seating was a challenge. We wanted a seat that would be suspended from the sides and not touch the bottom fabric. It should be very comfortable and easily packable - and not put undue stresses on the frame. The result is a sling type seat suspended front-to-back in a frame that rests on the chine rods. On top of the front support is an inflatable thigh support. The back band can be adjusted independent of the seat. We are very happy with the result!

PakCanoe Design

The first PakCanoes were made in 1995. Since then, they have been continuously refined into the rugged wilderness craft they are today. PakCanoes draw on over 30 years of experience with folding canoes in demanding wilderness settings.

PakCanoe.
In designing the PakCanoe our goal was to make a canoe that would be superior in safety, performance, convenience, and aesthetics. We think you will agree that we have been successful.

PakCanoe hulls are formed by a reinforced PVC skin held under tension by an interlocking framework of tubular aluminum. Seat positions adjust to trim the canoe. Because the PakCanoe hull is flexible you stay drier. Its flexibility allows it to ride over waves rather than crash into them and take in water. The canoe will absorb severe impact and usually slide over or by rocks with no damage where fiberglass, kevlar, or aluminum canoes crack or get hung up. In this respect, the PakCanoe behaves much like ABS boats weighing 20 - 30 lbs more.

Disassembled the PakCanoe stores in a 35"x18"x14" bag, small enough to fit in even the smallest car or closet.

Unique "Dual Shape" feature
The 14, 15, and 16.5 foot PakCanoes have the option of two alternative hull shapes. You can have a wide, relatively flat bottom canoe with excellent stability for family use or fishing. By replacing 5 cross ribs in the PakCanoe 150T you turn it into a deeper and narrower backcountry/whitewater canoe. Note: PakCanoe 150T is a wide and stable sport canoe. 140, 150, and 165 are deeper and narrower backcountry canoes with great whitewater performance (a 150 was used to run the Grand Canyon). If you'd like both options, a conversion kit containing the needed cross ribs is available.

Individual Parts:

1) Canoe Skin

PakCanoe skins are made of a heavy-duty synthetic fabric coated with high-abrasion-resistance PVC. Under each frame rod is welded a heavy-duty wear strip to further enhance abrasion resistance. Thinner reinforcement strips are welded over the gunwales. At each cross rib position a reinforcement patch is welded on the inside of the gunwale channel. At each end of PakCanoe skins a stainless steel D-ring is factory installed to serve as anchor point for ropes.

2) Closed Cell Foam Pad

A foam pad on the bottom under the frame eliminates pressure points where the skin would rest directly against the frame, and the effect is a great improvement in abrasion resistance. This medium density polyethylene foam is 1/4" thick and is attached to the canoe skin with a strap at each end to hold it in position. When the canoe is packed, the foam is rolled up with the skin.

3) Frame

Shock corded sections fit together to form all longitudinal rods, and parts are color coded for easy assembly. To minimize the potential for rod connections "freezing" (corroding so they can't be separated), we have built in a little extra space in the joints. The joints feel a little loose, but this has no effect on performance, and it it is likely to save you some problems. Shock cords are terminated at each end in a way that makes replacement easy if that shoud be needed.

Cross ribs and stems are bent to shape and have plastic hardware installed with pop rivets. The plastic clips interlock, and in some cases lock to each other. Lockable clips grab the gunwales securely, and latch clips on two longitudinal rods connect to the ribs on the bottom.

4) Air Tubes

Air sponsons between the skin and the frame greatly facilitate assembly. The frame is easily assembled with minimal tension in the skin, and the air sponsons are inflated to tension the skin and provide rigidity to the hull. Under way, the sponsons act as built-in fenders to protect the PakCanoe sides from damage.

Placement of air sponsons along the sides improves safety by reducing the amount of water in the canoe after a capsize and stabilizing it once it has taken on water. Each sponson has 3 air chambers so a puncture will not affect the canoe's performance.

5) PakCanoe Seats

From 2008 PakCanoe seats are similar to seats found in most rigid canoes, except that PakCanoe seats can be installed at several heights, and they are adjustable fore-and-aft.

Other versions of PakCanoe seats are adjustable to support sitting or kneeling positions. The change can be performed with one hand in 5 seconds - in or out of the boat. To trim the canoe, the seats can be moved to several alternative locations. A sliding seat is also available. The sliding seat can be positioned anywhere between two cross ribs. A sliding seat helps trim the canoe and allows fitting a third party spray cover with cockpit openings that don't match our standard seat placement. This seat allows limited space between the seat and the sides of the canoe when used as a stern seat.

6) Pump

The efficient yet compact double action pump attaches to the valves and makes inflation easy.

7) Repair Kit

A PakCanoe repair kit includes repair material for canoe bottom and sides as well as easy-to-use contact adhesive.

8) Storage Bag (35"x18"x14")

The storage bag is made of heavy duty polyurethane coated fabric and closes like a sailor's duffelbag. The bag's bottom is padded with a foam pad to protect the reod' shock cords.