WS Poly vs Duralite?

Can anyone speak on the pros and cons of purchasing a Wilderness System kayak made from the “new” Duralite material as opposed to the standard poly (other than the obvious 20% weight difference)?

only pro
is weight. the plastic is stiffer so they use less which makes it lighter and more flexy. me thinks the resin is a bit more scratch resistant in the duralite. maybe another pro.

another con is the need for the interior console, very much like a whitewater boat. sumthin’ to step over. not bad, IMO.


Hey Steve,

Did WS ever make the Tsunami in Duralite? When I bought mine last year, there was talk of making it for a March or April release. I opted for the regulat plastic, because nobody could confirm that there would be ANY weight savings with the Tsunami in duralite.

Do they make it now, and is there any weight difference between it and plastic in the Tsunami 140? They don’t publish anything on their website that gives the info.


Tsunami Duralite

– Last Updated: Nov-12-05 8:53 AM EST –

My 2005 WS Catalog has both the Tsunami 140 and 145 as being available in Duralite. The chart also shows a weight difference of about 10 pounds per boat. On a side note, a dealer I spoke with the other day said that there are several (he didn't elaborate as to exactly how many) more models/sizes of Tsunami's to be introduced in 2006.

like I stated above, the duralites do have a internal console to aid in hull rigidity but are lighter.


Is Duralite
a rotomold plastic or a thermoform material?

It is rotomolded.

What’s the difference in a rotomolded vs a thermoform plastic? Just curious…

Rotomolding takes polyethylene resin and heats and rotates it until it melts to the inside of a mold. Thermoformed boats take sheets of ABS plastic and heat then vacuum form them into the top and bottom halves of a boat. Most everyone is comign up with their own names for the thermoformed boats (TCS, Airlite, etc) but the technology is essentially the same company to company.

rotomold versus thermoform

Polyethylene (poly), the “classic” plastic for kayaks, is rotomolded. Rotomodling entails spinning a mold filled with melted (liquid) plastic. Poly holds up well to abuse but degrades in sunlight. It’s fairly heavy.

Fiberglass doesn’t hold up to abuse but is durable with care. With care, it will “last forever”. Fiberglas is lighter than poly (generally).

Duralite, Airlite, Carbonlite, etc are sheets of “ABS” like material that are distorted into shape by pressing them into a mold while being heated. Hence, these are “termoformed”. I believe the material is somewhat similar to Royalex, which is a common material for canoes (Royalex has been used in canoes for a long time). I suspect that Royalex is also “termoformed”.

The “termoformed” kayaks are very glossy and look kind of like fiberglas. The material is also quite thin. This construction is lighter than poly and fiberglas. It’s also cheaper to make kayaks using this method than using fiberglass. It might be cheaper than poly contstuction (but I don’t know). Manufacturers are pricing the termoformed kayaks higher than poly and lower than fiberglas.

Poly and fiberglas contruction have been around for a long time and are proven construction methods. Fiberglas, while brittle, can be repaired fairly easily. Poly can be repaired (by welding?) but I’m not sure if the repair method is very reliable.

I suspect that the big advantage of thermoformed construction is that it targets consumers who want the look of fiberglas but don’t want to pay for fiberglas (especially given how the prices for fiberglas has been increasing). I kind of suspect that a major motivation behind many fiberglas purchases is “looks”.

The termoformed construction is new and, in my opinion, not proven. In my opinion, it may not take the abuse that poly will and may not have the long life that fiberglas has. I have no idea how repairs would work on termoformed material.

Prijon extrusion blow molds

– Last Updated: Nov-14-05 5:54 PM EST –

their plastic kayaks. This process is quite different than rotational molding.

Extrusion blow molding entails extruding molten plastic through a large barrel with a large screw, and hanging a heated hollow plastic cylinder (parison) in the air. The mold [in the shape of the yak] closes on the parison, compressed air is blown into the mold with blow pins, and then the product is cooled through water lines in the mold. Any resultant flash (scrap) is then trimmed.

remember the old “Bo Knows” ads?
Well, bruce knows blow molding. Honestly, like Greg Stamer is a Greenland paddle guru, bruce will tell you about molding plastics. So ask away as he is fresh from a sabbatical in Wisconsin this past weekend.

Thanks Cooldoctor
Too busy catching up today to send an e-mail.

When I get ambitious, I’ll e-mail you the Door County pictures. There are no kayaks in them otherwise I’d post them here too.

Cool. Wicked cool.

WS Poly vs Duralite?
I have the Poly Pungo 120 and this year I tried the Duralite Pungo 120. Here are my comments:

1.) 10 pounds lighter.

2.) Overall the boat is not as stiff. When you pick it up by the hatch sides they flex.

3.) I dislike the stiffner that runs down the center of the boat between your legs. My dog does also as this is where she sits.

4.) The seat has been modified in that the thigh support is much shorter. In other words, the seat is not as long as the Poly version. I assume they did this for overall weight reduction.

i’m familiar with the perception airalite vs roto plastic. the weight difference isn’t that significant, but the stiffness and resistance to oilcanning look to be the biggest airalite advantages. i’ve seen a LOT of used poly kayaks with significant oilcanning on the bottom from racks/heat/etc which definitely affects tracking. the airalite looks great too! that said, i opted for fiberglass for my two boats.

good luck


strictly for looks…
…the Duralite is kinda shiny but not glossy like the thermoforms. The color is not as deep.

I think they will certainly be more resistant to denting/oilcanning, but time will tell if there are drawbacks.