Packraft Group Test ~ Introduction

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Supai Matkat • MRS Microraft  • Aire BAKraft • Nortik Trekraft • Alpacka Yak • Summary

The range of packrafts has slowly expanded since I bought my first Alpacka in 2010 and Alpacka rafts themselves have changed a lot in that time. But here in the UK people are still slow to see the benefits of these lightweight portable boats. As far as I know there are only two outlets selling packrafts in the UK and I’d guess about the same in most other European countries.
Much of this reticence must be due to the price of these niche interest boats which, at a glance look not much different from what I call Slackrafts: disposably cheap PVC pool toys. Another reason might be that packrafts appeal more to outdoorsy types looking for a new way to enjoy the wilderness or countryside, but with no interest in acquiring the technical skills plus storage and transport issues of hardshells. They won’t come across these boats very often but as this test clearly proved, anyone can hop into a packraft, set off down river in a straight line and tackle an Environmental Agency Grade III canoe chute. The testers all ‘got it’ and by the end some were already cooking up packrafting adventures.
5botsHere we’re comparing a prototype Aire BAKraft as well as the new Supai Matkat, both from the US; the Russian-made, German-branded Nortik Trekraft, and the Micro Rafting System (MRS) Microraft from China. The unusual Aire calls itself a hybrid IK-packraft, the Supai is an ultralight ‘crossraft’ intended for flatwater use. The other two more closely resemble Alpackas in current or former iterations. My current 2014 Yak made a fifth boat on our test, one which I at least could compare against the others.
packrafting_store_logoThese four boats were lent to us by the Packrafting Store in Germany which sells, rents and makes the biggest range of packrafts and packrafting gear in Europe. Sven at the Packrafting Store helped clarify or correct technical aspects in this review but the opinions, observations and most measurements are our own. Some of the more exciting photos are also from the Packrafting Store. We asked NRS to participate but they didn’t answer. Feathercraft’s packrafts are another option, but  they aren’t sold in the UK, and according to Feathercraft’s front page in early 2016, FC’s range of boats is now reduced to folding kayaks only.

pgt-lowboarts


gpt-medwaymapFor this group test it would have been great to set off across the hills of Wales or Scotland, deploy the boats and then follow a river, hop out, walk some more, set up camp and swap notes.
The reality of combining good weather and four other people with the free time to help do all this was slim. So we settled on an eight-mile day trip down the Medway River in Kent (above): me and four testers who’d all paddled (some with trousers rolled up) but had never packrafted. At each lock and chute we swapped boats, so everyone tried each raft at least once.

pgt-meMe – Height 1.83m; weight 91kg
Experience: Into IKs and packrafts for day trips and touring. On my third Alpacka.

pgt-bobBob – 1.78m; 85kg
Lilo incident, Margate 1965. Lea River canoe lessons, Harlow 1980. 

pgt-hanHannah – 1.75m; 75kg
Much canoeing, some kayaking, love touring. Don’t understand eddies, yet.

pgt-loLois – 1.62; 63kg
Dicking about on the Thames in Gumotex IKs and a Dagger. Rely on enthusiasm rather than skill.

pgt-robRobin – 1.78m; 85kg
Scouts canoeing, NZ white water, Colorado kayaking, various inflatable trips, usually with tides.

How the packrafts were weighed and measured
Weighing was done using the classic Salter 1004 SSDR digital kitchen scales. They come with a classy brushed steel finish and  still rate at 4 stars on amazon. They were checked and registered 500ml of water as weighing 500g.
gptmeazEach boat was weighed exactly as it came out of the box, and then weighed again as it was actually paddled, without air bags, repair kits or straps (where included). It was then weighed again before going back in the box. All dimensions were also taken twice, the second time using stakes to get the external measurements at the widest points (above). Internal dimensions were taken at the shortest point, usually halfway up the curved tube side. Measurements from other sources may vary; there’s a table at the bottom of each review’s page and the summary for quick comparison.
* Our exterior measurements for the Matkat were 3- to 5cm less than the Store, but 4cm longer and 1.6cm slimmer than Supai states. Unnoticed leaks during the measuring stage may have stopped us pumping the boat up to actual size. 


Construction
All these packrafts are made from pliable fabrics which form airtight vessels when inflated by human power alone. That’s about 0.03 bar or 0.4psi according to the Packrafting Store’s tests and probably too low for a regular manometer to measure accurately. The BAKraft uses an in-line ‘squeeze pump’ to potentially attain 0.17bar or 2.5psi – firmer than most recreational IKs. All the models used here except the Supai were pressure tested to an impressive 0.5 bar (7.25psi) by the Store without exploding into a blaze of harmless TPU shards. As a comparison, my old Grabner ran 0.3.bar as was as stiff as a gangplank.

Hardshell-like rigidity is an inflatable boat’s goal, and while design and shape might come into it, some rafts become more rigid than others and so perform better. The best rafts use a fabric (or construction design) which becomes stiff when inflated but is pliable when folded (especially at low temperatures) as well as being durable against sharp impacts and abrasion. Among other things you could add resistance to UV rays, ready supply and ease of assembly in the factory, repairability on the trail, and a range of fabulous customer-friendly colours.
gpt-MRSsewBroadly speaking the hulls of the Alpacka and MRS use ten panels of urethane (TPU) coated nylon fabric which are sewn together. Tape is then heat welded over the seams. The Alpacka fabric is only coated on the outside (pgtYAK15below right); the Nortik (below left, also ten hull panels) uses a similar double-coated fabric to the MRS (left; green, but not our Trekraft), but the Nortik’s seams are heat-welded with thicker tape (no sewing). 
gpt-trekseamDouble-coating adds weight and other technical aspects of proprietary coated fabrics vary greatly; they’re often specifically formulated for a raft manufacturer. The benefits of an inside coating are a second barrier to punctures when a light scratch to the exterior reaches down to the fabric core but doesn’t actually cut through it.
gpt-underbotsThe floors on the Yak, Nortik and MRS are glued on then taped over (Nortik on the inside, the other two outside). They’re typically two or three times the denier rating (thread weight) of the hull fabric.
The Alpacka uses something called ballistic nylon which sounds cool but I’ve found is far from bulletproof. No part of an inflatable raft weighing just three kilos can be expected to be. Occasional repairs are all part of ownership, like a bicycle’s tyres. So is rinsing any grit out the boat before it works its way into the nooks and crannies. On the right click the extra large picture to have a close look under the boats and compare workmanship.
pgtMAT07The superlight Matkat is in a class all of it’s own, entirely made from 75-denier ripstop polyester with a single urethane coating on the inside, the same weight (and sealing method) as an MSR water bag. The red picture below right is of another Supai we tried which you’ll see had a diamond pattern on the surface. su-msrfabThe black Matkat we used here had a plain surface like an MSR bag. On both boats the four panels (floor, inside, top and bottom hull) are then heat-welded together.
 It’s possible to repair these seams with a hot iron (or glue).
pgtBAK30The Aire BAKraft prototype we tested used a thin and slightly stretchy urethane  film ‘inner tube’ or collar supporting the hull, and a much thicker and stretch-free urethane-coated yellow nylon fabric for the I-beam floor (left). These bladders or ‘AIREcells’ as Aire calls them, are contained inside a sewn-up shell of fabric which need not be air- or watertight. If I interpreted the owner’s manual correctly then the BAKraft’s green exterior shell is made of Spectra and the grey interior of lighter-weight Dyneema fabric. You may know stretch-free Dyneema guy lines found on better tents. 

pgtBAK31The urethane bladder can be accessed for repair via long zips (left); the nylon floor can be pulled out for repair from each end. On packing or refitting care must be taken not to twist the bladders. I’ve never been a fan of it (for reasons explained later) but this AIRECell system has been used by Aire on their PVC whitewater rafts and IKs for many, many years. With minimal seams compared to a traditional packraft hull, air retention is excellent.
On all the boats seatsbackrests and decks (where present) are typically made from urethane-coated nylon with seams or joins heat-welded and maybe taped.

pgtMRS11Inflation/deflation
If you’re combining walking with navigating bodies of water – packing + rafting – you want a boat which inflates and deploys without any faffing about. In this respect the Microraft was the best of the bunch. It used the proven screw-in inflation bag (see video below) and, being a small volume boat, took about ten ‘scoops’ to fill up. The main valve cap is attached with a short plastic ring tab – no fiddly bits of string. Top off the air pressure by blowing all you got into the twist-lock valve and with practice you’re good to go in three minutes.

In the video below, from arriving at the beach to paddling away
takes about 8 minutes. Speeded up 15x. A jet passes overhead.

yak-airbooMy Yak followed exactly the same inflation procedure, but being a higher volume boat (a little bigger than the one in the video above) took twice as many ‘air-grabs’ to fill up before topping off with lung power. Every time I do this I wonder whether my super-thin airbag will split or unravel at the seams if I scrunch too hard. I can feel the air leaking through the sides.
pgtTRK08Like the MRS, the Trekraft’s airbag is also made from a reassuringly thick fabric, but is spoiled by a push-in plug, even though there’s obviously a thread pgtTRK03in the boat’s port. Compress too hard or if it’s wet and the bag plug might pop out, so inflate gently. Instead of using a twist-lock to top-off, the pgtTRK02Trekraft has a one-way spring valve with a cap (which came adrift and eventually got lost). This valve (above right) is dead easy to use and avoids the risk of over-tightening a cheap plastic twist-lock valve (as on older Alpackas). But when airing down, with the spring valve you can’t suck and seal the remaining air out unless you jam something in the valve as you suck. Packraft or IK, this ability to suck your boat down is handy for compact packing.
Next comes the Matkat. No airbag supplied even though the Supai website states: ‘We are working on developing an inflation sack to work with our valves hopefully we will have it released in mid-2014.’ When we tried the smaller red Supai Canyon Flatwater II in late 2013 we found it took about fifty breaths to fill, plus topping off. The higher volume Matkat takes about eighty breaths. I like breathing but that’s not something I’d want to do more than a couple of times day to save the 100 grams of an airbag.
pgtMAT08Unlike the Alpacka, Nortik or MRS, the Supais use a male threaded dump valve which protrudes from the boat and onto which screws a cap with a thin tube and the twist lock valve on the end (right, red boat) – a neat and simple system that’s just about accessible for on-board top-ups.
supaivalveAlpacka use an identical threaded valve port but on their air bags; it’s a regular American plumbing ¾-inch size. If I had a Supai packraft I’d get an Alpacka airbag for $20 and then either find a female-to-female plastic connection, or jam on a short section of clear plastic tube to join them together. That way I can save the hyperventilating for Glastonbury.
pgtBAK23That leaves the BAKraft. Even before I received the boat I had my doubts after seeing pictures of the convoluted inflation system which Aire suggest.
The BAKraft uses Halkey Roberts (or very similar) valves, as found on proper IKs and whitewater rafts: one in the floor and one for the urethane bladder that fills both sides of the hull, or what what they call the ‘collar’. These valves work like car tyre valves (or the Nortik top-up) – a spurt of high pressure opens the seal and a spring seals it shut – except that you can lock them open by pushing and twisting beg02the valve stem. This is necessary to deflate a boat easily, or to loosely pre-inflate it without having to push against the valve spring. These valves are really designed to be used with pumps not flimsy air-catching inflation bags, far less lung power. A simple and compact push-fit pump like a K-Pump will work. A high-pressure stirrup pump with a ‘Summit’ bayonet connector on the end will be even quicker, but is way too bulky to travel with.

pgtBAK06gpt-BAKair1With the BAKraft you’re supposed to use the backrest/cargo bag as an inflation bag and scrunch air into the boat via a tube fitted with a bayonet connector (left). But the backrest bag’s weight, odd shape and relatively small volume makes this task awkward, even past an opened intake valve which is still a restricted airway. I gave it a go  but soon saw that, while I’d get there in the end, it was going to take ages. gpt-BAKair2
Once the boat has ‘shape’ you’re then supposed to quickly close the boat valve then splice in a low-volume/high-pressure hand-squeeze pump into the ISC bag. The squeeze pump has another one-way spring valve in it: charge it with air from the backrest then squirt air by hand past the closed valve until the boat is firm.
This squeeze pump is quite a clever idea but at about 150cc a go will take a while to do the job. Sorry to say I wasn’t even curious to find out how long – I’d guess at least 15-minutes for the whole inflation, same as it took to pump up my 4.5-metre kayak the other day with the one-litre K-Pump Mini. So instead I reached for my Bravo stirrup pump – it Bagpipertook two minutes – and on test day I brought my compact K-Pump which took about twice as long.
I see now that I’ve actually RTFM I used an alternative method. The image above right suggests you don’t use the backrest bag to charge the squeeze pump, but just blow then squeeze the hand pump directly using an oral tube, like a silent bag pipe. If I’d thought of that I might have tried it as it’s a much less clumsy way of topping off the BAKraft.
pakv1All the other packrafts here run at an air pressure that’s governed by the lung power you can exert through the top-off twist valve (left). But with a one-way valve you can pump more air into a raft (that goes for the Trekraft’s top-off valve too, now I think of it). The BAKraft is made to run an IK-like 2.5psi although you’re warned not to over-pressurise or allow it to happen. That can be easily done of you get carried away with a stirrup pump or leave the raft out in the hot sun.
It may have seemed clever to give the necessary backrest multiple uses, but it works only a little better for filling the boat with air than it does as a backrest (see review). I’d recommend getting a $20 Feathercraft inflation bag which comes with the ‘Summit’ bayonet fitting from their BayLee packrafts (they also use Halkey-like valves). And if you don’t get on with the oral/hand pump system, then get a 600-g K-Pump Mini too. I’d guess using both these devices will more than halve the inflation time.


gpt-groupieFrom the four corners of southern England the throng gathered at Tonbridge Town Lock, the boats got pumped up, cooled off in the water then topped up some more. Then after a quick groupie, we set off down the easy first chute. I took it upon myself to get in the Matkat while I was still feeling fresh.

 Supai Matkat • MRS Microraft  • Aire BAKraft • Nortik Trekraft • Alpacka Yak • Summary
This entry was posted in Alpacka Yak, Cheap PVC 'slackrafts', Gear, Packrafting, Tech and tagged , , , , , . Bookmark the permalink.

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