Hull Material

Is there a difference between royalex and ramx. if so what is the pros and cons between the two. Thank you

Do they still make Ram-X?

– Last Updated: Mar-10-11 1:12 PM EST –

I remember Ram-X as being in the old Coleman canoes. It's terrible stuff. It's a single layer of plastic (I don't know what kind), and it's heavy and doesn't maintain its shape properly at all. Every Coleman canoe I've ever seen that was made of Ram-X has been badly warped. On the other hand, the material is dirt-cheap.

Royalex is lighter, and is used by many better canoe builders as a material with good impact resistance. Unlike plastics, it's a multi-layer material. It doesn't produce boats that paddle as nicely as composites (fiberglass, Kevlar, carbon fiber), but it's cheaper than composites and a lot lighter than either Ram-X or polyethylene.

two different types of plastics …

– Last Updated: Mar-10-11 2:11 PM EST –

..... RamX is a trade brand name used by Coleman and other canoe/kayak mfg.'s to decribe what their plastic boats are made of .

RamX is the plastic known as XLPE (or PEX) , meaning it is a crosslinked polyethylene and most always a HDPE polyethylene (high density polyethylene) .

So to simplify , RamX is a crosslinked high density polyethylene . The Ramx hulls are usually a single solid layer thickness and built by the process of rotomoulding .


Royalex (another trade name) is a composite (combination) of Vinyl outside layers , multi ABS internal layers , and ABS foam core . In other words it is a multi layered sheet material with it's layers bonded by heat .

Royalex canoes would be built (I think) by heating the sheets and setting them to a hull mould in a vacume wrapping process to achieve the desired shapes .

Royalex is by far the superior product for canoe hulls when compared to RamX , but both can make a canoe that floats and paddles .

hey , I have a question if anyone knows ... are there any kayaks that are made from Royalex (I don't think I've ever heard of any) ??

Your last question
Plastic kayaks are rotomolded, but the material used to make Royalex canoes starts out as pre-manufactured sheets. I’m no engineer, but I can’t imagine a way to bend a sheet around into a tapered, tubular structure in such a way that the two edges of the sheet join at a seam that is both structurally sound and unobtrusive. If you put some kind of reinforcement patch overlapping that seam, I’m sure it could be done. Seems like it would be pretty awkward though, especially at the pointy ends of the boat.

pilotwingz, back in the latter 70s or
early 80s, Old Town offered Royalex ww kayaks. I never saw one in the flesh. They might have been unnecessarily heavy, and in such small dimensions, too stiff, so that hard rock contacts would smash the ABS structural layers. Royalex does better in larger hulls, where its stiffness advantage over PE helps make hulls hold form.

Yes
Raven Works used to make a Royalex (actually R84) 15’ 8" kayak designed by John Winters - the Tourlite. It looks pretty good. http://www.touringkayaks.com/Inactive/tourlite.htm

I think that answers my question too
Looks like the seam was around the edge of the top deck.

Wow! A Rx LV QCC400X.
Cool. Same weight as my kevlar 400X and lower deck.

that’s pretty cool …

– Last Updated: Mar-13-11 6:42 PM EST –

...... I just wondered about a Royalex kayak .

Wonder why it's not a more common thing in plastic kayaks as in canoes . The plastic in kayaks is mostly the same thing as you would find in Coleman RamX really , XLPE-HDPE isn't it ??

Roto moulded crosslinked high density polyethylene .



Shape
It’s been my observation that Royalex solo canoes, like the Mad River Guide I once had, are just great. A 17’ or greater Royalex tandem tripping hull like the Old Town Tripper or Novacraft Prospector either is very heavy (I have a 94lb Mad River) or has a pretty floppy bottom. This may be a fair price to pay for the weight/impact resistance, but the fact is that if you want a large, flat surface in Royalex to be stiff you need to add a lot more material. A small, curved surface like a kayak or solo canoe can be made much stiffer out of the same material.



I paddled a P&H plastic Capella and found it to be adequately stiff (I believe that is because it was narrow, and had a shallow v bottom)



To sum up - kayak designers can make good boats out of plastic that canoe designers cannot. I have no beef with the Coleman plastic, but it is ill-suited, and the Coleman canoes are very poor in my experience.