Adding kevlar mat and resin skid plates adds 2 or more pound to a Royalex canoe. Is there a way to do it lighter? Would epoxy be lighter than resin? Kevlar cloth with epoxy? Diagonal cut fiberglass cloth with resin or epoxy?
Worrying about adding the extra weight of skid plates to a RX boat is similar to being concerned about the weight of a coat of paint on an anvil.
More concern should be addressed to the hydrodynamic effect - skid plates increase forward drag and hog the hull - dropping the stems to compromise turning. If the designer wanted a bulb bow on the hull it would have been drawn in at the design level.
All that said:
No weight difference of any significance between Epoxy and VE resins, but epoxy may bond more fully to the vinyl outer on RX hulls.
Kevlar felt is the preferred medium, but a biased cut, diamond shaped 9.5oz Kev patch would reduce weight and, more importantly, profile.
If you can find it, Vectran has ~3.5 X the abrasion resistance of Kevlar unfinished and ~13.5 X finished, for a better profile yet.
I do appreciate your answer, Charlie
My Royalex boats, like most everyone else on this forum, are used heavily in white water tripping where ledges rip boats and portages are up to 3 miles long, and when you wear through the outer layer its time to put on a new coat.
Here’s an interesting treatise
underlines your suggestion for S glass.
On a side note, some friends of mine have been taking ADS plastic pipe which is polyethalene and dissolving it in Acetone to the consistency of thick paint then painting it on wear areas of their hulls. Trick seems to be letting enough Acetone flash off so it won't eat through the hull but leaving enough Acetone to help the ADS adhere to the hull. Have you seen any tests of this method? It scratches, but seems to hold up as well as you would expect ADS pipe to hold up.
It's unfortunate your sense of humor has deserted you; hopefully only momentarily. I'm always trying to be amusing - obviously not this time - sorry. I certainly didn't mean to denigrate you.
Royalex is a fine medium for price pointed canoes that may face some abuse. Unfortunately, it cannot be shaped to provide fine entry lines or compound shapes. It also cannot be kept from oil-canning - especially in the RX Lite form mostly now used. And, it is always heavy.
Still, I've spent ~100 days in RX hulls, most recently on the Cahaba in Alabama last month I wrote the letter that convinced our bankers that Bell should make RX rather than FG entry-level hulls.
Serious whitewater competitors, say Olympic Slalom boaters. both K-1 and C1, use composites because they are more efficient and faster due to fine entry and exits, compound shapes and no oil-canning, and lighter, hence more responsive.
Our Placid boats aren't always little and are always rugged. Our XLT WildFire has 57oz of Carbon and Kevlar fabric under the seat and 62oz of fabric in the stems, all resin infused with an epoxy, biphenol, based vinyl ester resin under a layer of protective gel. It weighs 26 lbs with our super seat, doesn't need skid plates, and will outlast RX Lt hulls if you don't wrap it. Both David Yost and Bill Swift say we overbuild out hulls.
That said, Hemlock also makes fabric cored hulls by contact lamination that will withstand serious abuse. I am always suspicious of foam cored hulls . While lighter, the very rigid cores act as stress risers around their edges, and repair is always exciting, in the Chinese sense of the word, when the core itself is breached.
I'll be glad to mail you biased cut Vectran skid plates, NC, when our sample goods come in. We're pretty excited this may be the next big thing in composite lamination. While eliminating moisture pickup and abrasion in high tensile strength, inner, laminate layers, it should make great skid plates for RX hulls that are wearing through.
Andy Lee, thanks for that link.
Interesting info on cloths used for covering wood.
Plasti Dip is made by the same company that makes Vynabond.
It's available at hardware stores and Lowe's. I'll try it out today to see how it adheres to Royalex. Should be interesting. It comes in several colors.
you’ll want knee cups or thigh straps
That stuff is made to be grippy
Grippy and scrapy
I just got back from the hardware store and looked at a couple tools they had used this dip on and it is indeed “grippy” and you can take a coin and scrape it right off the tool. Too bad, it would have been a convenient fix.
One thing I did discover at Lowe’s though, is plastic paint by Valspar. I bought a can of the blue to touch up some scratches above the waterline on my Raven. I was going to use regular house trim paint but this stuff might be better. We’ll see.
Welcome back Mike,you had good weather for your trip, eh?
I mixed some epoxy with a fair amount
of cabosil and painted some skid plates on the Voyager. I haven’t skidded it on anything yet, so I don’t know how it will hold up.
I found this to be interesting reading
May be an alternative to skid plates.
I didn’t read his reply that way…
When the end of my canoe wore through to the foam core four years ago, I mixed up some of this epoxy paste product and sort of troweled it on with a putty knife as smooth and thin as possible. A little sanding and another application did the trick. Mfr. says it’s tintable with universal colors, but I just left it white. Stuff seems tough enough and has stayed on better than expected-kind of like Bondo for Royalex!