R-M Process. Good/Better/Best?

I have been viewing various plastic sea kayak models and their user reviews for the past month with the intent of purchasing my first kayak. I have narrowed my search to skeg models 16 to 17.5’. I am looking at plastic because of the lower price. What is obvious is that different companies use different RM techniques eg: Prijon HTP, P&H/Valley triple layer (on some) and then there is just plain RM by CD/Wilderness Systems/Perception/Necky. Numerous reviews slam boats/manufacturers for “oil-canning”, and this complaint seems more prevalent with certain manufacturers using regular RM processes than others.

In my area (Winnipeg) comparable models of plastic boats are all priced the same (or at least within $100 of each other). So, is it safe to assume that there is really no difference or better quality boat based upon the RM process? Do ALL plastic boats oil can if left in the hot sun for a long time, or is this a reflection of the quality of the plastic AND the process? Does oil-canning even have any effect on how a boat paddles or performs?

Any insights/info would be appreciated.

one horse’s mouth
the R/M process varies alot between manufacturers.

Prijons are blow molded. they extrude a large tube of plastic and then close a mold over the tube and then use air pressure to ‘blow’ the shape. expensive machine and mold. they can use a stiffer plastic but… still is easily oilcanned.

oil canning is as much a function of hull design as it is plastic type/ R/M process. any boat will oilcan given the right heat/ pressure. even composite!

the triple layer boats are done in stages with the mold being opened and another material introduced into the mold. more material/ more weight/ more stiff?

Mad River makes a canoe using this process TT or triple tough. we choose NOT to go there w/kayaks.

hope this helps.


Confluence Watersports R/D team

New Valley plastic
A friend just got a new poly Avocet. I am very impressed with its stiffness and its lightness (for a poly boat). It seems stiffer and lighter than earlier plastic Valley boats.


– Last Updated: May-26-06 4:58 PM EST –

Prijon is not rotomolded, but rather blow molded. Rather than melted pellets rotated in a kayak mold, the blow molding uses a longer molecular structured plastic, melts it, and blow molds it (air compression at high pressure) into the mold. Makes for a tight and light plastic kayak.

For instance, look at the basic but wonderful Prijon Capri Tour. 12 feet. 42-44lbs (depending on what literature you read). Use that as a base to see if any other heavier rotomolded kayaks can match it for weight. Investigation will reveal that other 12 foot rotomolded kayaks are 50 lbs plus.


By the way, I cinch my Prijons down hard enough to see the hulls flex farly significantly, and I drive in the hot sun to paddle spots sometimes as much as two hours away, and when I take it off the truck? Voila. No oilcanning. I saw the Prijon Seayak at my dealer, was on a wall rack that held the hull bottom flat in only two places (a no-no), and it did oil can slightly... but presumably would bend back if given the chance. It likely was on that rack untouched for a year. Anyhow, I think you will find it hard to find a plastic that resists oilcanning better than the longer molecular structure of the Prijons.

Good luck on your perfect kayak search. Buy right to begin with and you'll be one up on the rest of us that bought too short, too wide kayaks and outgrew them skills-wise in one season or less. :)

Oil canning

– Last Updated: May-26-06 3:19 PM EST –

Triple layer plastic like P&H uses has a pretty good reputation for stiffness and they do oil can less than single layer rotomolded boats.
Blow molded plastic is tougher and stiffer than the generic rotomolded and is also less prone to borh oil canning and gouging. I've seen old prijons that held up great.
I guess youre picking between WS Tempest,CD Scirocco,P&H Capella,Necky Chatham and Perception Avatar? Too bad i haven't had a chance to try any of those,though i'd like to. Heard very good things about the Scirocco on my local board(westcoastpaddler.com) and heard good about Chatham. I'd eliminate the Tempest on the spot. I've looked at em at the store and the plastic feels significantly flexier than the CapeHorn i had, and even that oil canned out of the blue.
Down here in BC the GOOD plastic boats(Prijon,P&H) actually are a few bucks cheaper than generic. My dream boat is still the SeaYak even though it does have a rudder instead of a skeg i'd really like, it has gas-pedal style pegs.
By the way, something i thought of..If the main reason you're after a skeg boat is solid footpegs, you can get a rudder boat and install gas pedal style aluminum pegs from Seaward. very well made system.
Also, oil canning is more dependent on your roof racks than anything else and how tight you strap it down. I found my new Elaho is happier being strapped in upside down, this way its laying on the flat deck and the straps follow the curve of the hull without making any pressure points. I've seen someone with a plastic kayak strapped to bare square tube roofrack and tightened enough to make a 3 inch crease in the hull Gee i wonder if thats going to oilcan.
BTW, Reason why "confluence"-WS,Dagger,Perception are not using blow molding or multi layer is they know they can sell very mediocre quality stuff for the same money as good quality stuff, so why invest money in more expensive equipment and tooling.
I got a new Necky and from what i've seen, they don't seem to oil can much, and i like the boat, but given the same price i'd go for a Prijon in a heartbeat.

disagree about the tempest plastic
Maybe you got a bad batch to look at but the Tempests I have been looking at are quite stiff and seem to be exempt from some of the comments being made about quality control at confluence/Wilderness Systems. haven’t seen them all obviously, but the ones I have, in three different paddleshops, seem no lighter or flimsier than the one I own that is probably three years old. And it ain’t flimsy or flexy. does weigh in at 60 lbs though.

Just my 2 cents.

gotta agree.


Not sure if this is true
but I heard that the reason Prijon make blow moulded kayaks and the others can’t afford to is that Prijon bought the equipment from a windsurfer manufacturer that went broke. Can anyone verify this?

Prijon has been making BM kayaks since before windsurfin’ was invented.


Triple Tough
Triple Tough will oil can just as much as any other material. I worked at a paddle shop and we recieved a Mad River TT canoe with a massive oil can in it.


– Last Updated: May-27-06 9:41 PM EST –

I bought my T165 a little more than a year ago and have not had any problems with it. And while I take good care of it (rinse it off after each day trip, store in a shed), it is not babied. When I use it for camping, it sometimes gets pivoted around on land with camping gear inside it. It has the scratches to show for that, as well as from paddling in shallow, rocky water.

I don't understand the comments about loose hatch covers. Mine fit tightly and have never come off. No skeg leaks. Hull is holding its shape very well despite being strapped into cradles that do not fit it (they were specially made for a 4-panel stitch-and-glue kayak).

Frankly, if the plastic eventually warps, I will replace it...with a composite T165. Not a "superior plastic" kayak of another model. My first kayak was an Old Town Castine made of noticeably stiff plastic (I think it had foam sandwiched between 2 layers of plastic). I liked the stiff plastic but that's not enough in itself. I'd rather paddle a kayak that behaves the way I want it to than admire the shape-holding ability of a stiffer one that doesn't.

I'd bet money mine is under 60 lbs. It feels only slightly heavier than the wood boat that I weighed in at 52 lbs BEFORE MODIFYING the outfitting--I'd guess the wood boat now weighs 54 to 55 lbs. Haven't weighed it since the mods. Haven't weighed the T165, either. I need to take that scale outside and try it...

Necky’s rotomolded Manitou 13…
…claims 45 lbs at 12’10". I can’t verify the actual weight, but I carry it 300 yds from my house to the local lake with little trouble…and I’m no strongman.

My experience…
…is that the prijon boats have features

generally not found except on more expensive

models. Comfortable seats, better foot pegs

(Prijons have gas pedal type foot rests and NOT

pegs), adjustable thigh braces, extremely tough

plastic, etc.

Demo them all, but demo the Prijons.

(I do NOT work for Prijon or derive any money

from them. I am an enthusiastic consumer.)

Just googled a few things
Prijon bought there first blow molding machine in 1981 so windsurfing was around but the big crash when a lot of manufacturers went broke came later.

This means their blow molded boats predate the Dancer which as far as I know was the first RM whitewater boat. There was a RM kayak made in Australia a few years earlier called a Hagar 4m but it wasn’t for whitewater. It was made in two pieces and joined, similar to composite boats.

Does anyone know of any earlier plastic kayaks?

actually . . .
You’ll find comfortable seats and adjustable thigh braces in other brand boats too. The foot pegs aren’t a big deal to me, and if I remember correctly, the Prijons only have the gas pedals if you install a rudder. I like the Prijons - I used to own a Barracuda - but disagree with your comments.

As far as test paddling is concerned, I spent some time in the Barracuda and Seayak when I was looking to pick up another plastic boat this spring. I also paddled some other brands, and wound up with a Tempest 170. Nothing against the Prijons, but the Tempest is much more to my liking.

Thanks to everybody who replied to my post. I originally hadn’t planned to look at the Prijons, but now will add the Seayak to my test paddle list. The Capella RM was a given for testing, but based on the love-'em or hate-'em that a lot of paddlers seem to have with the WS Tempest I will defintely paddle it as well.

As far as oil canning, I guess having a good cradle that offers up hull support and not ratcheting straps too tightly will help alleviate or minimize some/most of the problem?

Thanks again.

The seayaks weathercock very easily. Paddling it without a rudder can be a bit annoying.

Hollowform River Chaser was first. Probably 1977 or 8. Made in North Los Angeles.

There were a bunch before the Dancer.


Wisljo: “A friend just got a new poly Avocet. I am very impressed with its stiffness and its lightness (for a poly boat). It seems stiffer and lighter than earlier plastic Valley boats”.

I agree, and I am a died in the wool Prijon guy. My friend just got an Aquanaut and the plastic is second to none. It is even less felxy than the Prijon. Valley has a three layer system that allows, get this, a different color on the interior of the hull than on the exterior. Very unique, much like fiberglass. I would consider buying a Prijon or a Valley kayak.

where have you been.
Actually, every multi layer boat i’ve ever seen, Old Town,P&H, all have different color on inside than outside. It’s a dead giveaway of a multi layer boat.