• Happy Birthday, Meriwether Lewis (1774-1809)!

Cliff Jacobson: NO to skid plates!

Glenn MacGrady

Administrator
Staff member
Joined
Oct 24, 2012
Messages
2,881
Reaction score
1,077
Location
Connecticut
The black hull was the following year, a 6 week nearly 600 mile trip

I remember. That's the kind of wilderness river trip that's out of the norm for most canoes, so, as I said, it does make sense to beef up a stripper/composite canoe when your life depends on it. If I were young and strong, I'd probably only take a Royalex canoe on an igneous river, even if that seems ignominious.

You did a nicely dense pattern with the scratches, even up past the waterline. The diagonal and horizontal ones must have been exciting.

These were not highly rockered boats so if I found a rock, which happened regularly, the stems usually took the first hit.

That's an interesting point. All my dedicated whitewater canoes are highly rockered, so that's probably part of the reason I don't have much stem damage on them. And I've never run any of my composite lake canoes or kayaks on rocky whitewater, and always wet foot them. Come to think of it, I've never taken a composite canoe on a long trip that had both lakes and whitewater rivers. I bought my SRT for that purpose, but . . . .

I've also found that since I started building canoes I'm more likely to be hard on them.

I've wondered whether paddlers who like to build and repair boats have that sort of psychology lurking within. I know I have the opposite psychology. The only "glassing" I've ever done in my life was that one set of skid plates 40 years ago. Otherwise, I've paid people to repair my canoes. And since I'm cheap, I've probably always tended to be very careful with my composite boats. Nick Schade, kayak builder extraordinaire, once told me I was babying my carbon hull seakayak when I refused to run it aground in the Bay of Fundy and opted to do "fall out landings" instead.

By the way, for Mike McCrea and Steve'n Idaho, that full carbon infused hull has clear gel coat with gold flecks in it, per my custom specifications. The builder had never made one like it. I bought a Swedish carbon double paddle (Vitudden or VKV) that has the same thing, which I'll try to get in a picture below. Well, you can see the flecks, but the flash has washed out their gold color. The hull of my Surge seakayak is the same, while the deck is Kevlar with yellow gel coat and the deck-hull seam is red.

NQr7imc.jpg
 
Last edited:
Joined
Nov 14, 2018
Messages
1,091
Reaction score
238
Location
Heart of the Shawnee Nation
Interesting discussion. My wife refuses to land properly so I know both her kayaks are being chewed up. Good place to try Dynel skids.

A quick search found dynel fabric in 100 yard rolls. Is there a source for shorter bolts?
 
Last edited:
Joined
Jan 8, 2014
Messages
1,291
Reaction score
286
Location
Minden, NV
I am currently repairing a w/c OT. The forward part of the stem has been crunched over the years, so I added some epoxy with wood flour to firm it up.
 
G

Guest

Guest
I put the later-to-be-discovered-unnecessary Kevlar felt skid plates on my first canoe, a yellow Royalex Mad River Explorer. Never again, on any of the next 14 boats, for the reasons stated by Jacobson and me. However, I cannot believe that a couple layers of ugly black Dynel are more effective against abrasion or collisions than ugly yellow Kevlar felt.

Glenn, you have at least been honest in decalring that you have no tools, no boat-working skills and no canoe tinkering desires. Confession is good for the soul. Say two Hail Mary’s and three Our Father’s you can be forgiven for never messing with a canoe in 40 years of paddling

The ugly yellow kevlar felt is fairly abrasion resistant, especially if installed with old-school urethane resin, that resin itself being seriously tough stuff. The abrasion resistance on kevlar felt is largely due to being a very thick layer. A thick, heavy sacrificial layer that I have worn through on some kevlar felt skid plates.

The impact resistance of kevlar felt is more suspect, depending on how resin-rich the felt was saturated. Folks have cracked off chunks of overly resin rich kevlar felt; using every ounce of too-much resin in most skid plates kits is not a good idea, even if you did pay $300 for that crap.

There again the slid plate materials experiment showed that a single layer of Dynel is as impact resistant as kevlar felt, and a two-layer skid plate, even Dynel over glass tape, is significantly more resistant to impacts.

That's the kind of wilderness river trip that's out of the norm for most canoes

I have never done a six week or 600 mile trip, and likely never will. My longest trips have been half that in duration, and more often in the week to ten day or 100 mile range. However, a number of my tripping canoes (and day paddling canoes) have hundreds of trips and thousands of miles on them, and were eventually stem worn enough to need skid plates. And some of those (ugly Kevlar felt) skid plates later needed refurbishment(s).

This is the kev felt skid plate on my soloized Penobscot, photo taken last year . That is an Old Town urethane resin skid plate kit job, properly installed in 2003. Eight or so years ago the felt was so worn that I refurbished it with another coat of epoxy & G/flex mix. By last year it was again wearing down into the felt and again needed attention, this time with straight G/flex and graphite powder. When it needs attention again I will cover the worn kev felt with a layer of Dynel, which I should have done that last time.

PB040024 by Mike McCrea, on Flickr

Without skid plates there would be no stems remaining on the Penobscot.

Dismissing skid plates because you installed a set 40 years ago, using objectionable materials, is back to the “Bought a Yugo in 1986” analogy. Dynel fabric has proven to offer superior abrasion resistance. From the Sweet Composite catalog, I trust Davey Hearn knows what he is talking about.

Dynel fabric has very high abrasion resistance but swells in the resin such that it works better if vacuum bagged or pressure molded. The most common uses of dynel are for wear patches on boats, edgings on paddles, and the like. It seems to be a good choice anywhere that abrasion is a major issue.

I accept that you find black pigmented and graphite powdered Dynel skid plates, which, again, can be compressed 1/16” ungurgly thick and weight mere ounces, objectionably ugly. Dynel can be epoxy pigmented to match the hull color; on white bottomed hulls skid plates with white pigmented resin become largely invisible.

I will make you an offer. Bring your ancient yellow Explorer down to the shop and leave it for a spell. I will chisel or grind off the curling and peeling felt skid plates and replace them with flush, lightweight Dynel. I’ll even tint the epoxy yellow instead of black if you prefer.

Bring down that 300lb Explorer spray cover; we might be able to make a trade for shop services.
 

Glenn MacGrady

Administrator
Staff member
Joined
Oct 24, 2012
Messages
2,881
Reaction score
1,077
Location
Connecticut
Dismissing skid plates because you installed a set 40 years ago, using objectionable materials, is back to the “Bought a Yugo in 1986” analogy.

I don't dismiss premptive skid plates based on a straw analogy or any theory, but solely on 40 years of actual experience with 15 canoes and kayaks.

My boats include open and decked hulls designed for and used in hard whitewater, flatwater and ocean cruising and racing, both solo and tandem, and made of a wide variety of materials including wood, fiberglass, Kevlar, carbon, Royalex and thermoplastic. My actual experience is that I never have had significant stem damage on any of my boats, and hence my antipathy to preemptive skid plates has been empirically validated. I was wrong 40 years ago when I had a (gear slut) theory that I needed skid plates on my Explorer.

I accept that other people have had significant stem damage. There could be many reasons why that has happened to them and not to me. I've discussed some.

Finally, I believe it is both theoretically and empirically commonsensical to apply skid plates once there is actual stem damage that requires repair.

It's all as simple as that.
 
G

Guest

Guest
My actual experience is that I never have had significant stem damage on any of my boats, and hence my antipathy to preemptive skid plates has been empirically validated.
Finally, I believe it is both theoretically and empirically commonsensical to apply skid plates once there is actual stem damage that requires repair.

I do agree that, most often, installing skid plates before wear areas are shown makes little sense. Exceptions perhaps being taking a new boat on a long abusive trip, or when finishing construction on a strip-built hull while the boat, epoxies and materials are still in the shop.

Skid plates for me are not an irresistible compulsion. But I do abuse my boats – abuse, sometimes unavoidable, to which I previously admittedly; I can install or refurbish skid plates, repairing my already trashed spine is still beyond my DIY shop skills. I will note that not every place I paddle has pluff mud and fluffy kittens on the bottom, or even at campsite landings.

How to wear out canoes stems in six easy steps

Maine. Landing at a windswept rocky site. It was much choppier when I first landed, with waves beating the hull (and waist deep perched on slippery rocks me) against the shore. I threw a barrel and pack ashore to lighten the load and, yes, dragged the Monarch out of danger. Every second it was in the waves it was getting crunched, and so was I. Demonstrating how smart I am I later launched for an empty boat day paddle, and landed again in the same snot.

P8051195 by Mike McCrea, on Flickr

Utah. Ledge site (Turk Head IIRC) several feet above the water. Heaving the gear up onto the ledge is one thing, unless you have magical powers of levitation getting the boat up atop is quite another. Even if it isn’t a sheer ledge sometimes the only steep hillside choice is drag the canoe up the bank.

P5091038 by Mike McCrea, on Flickr

Florida. Monarch landed and pulled above high tide line on a crunchy shell beach for the night. The raccoons playing trampoline on the spray cover that evening didn’t help. Next time I’m tying mouse traps to the deck rigging. Dammit, there’s nothing in the boat except my paddles and PFD ya ravenous, thirsty, site habituated little bandits.

P2051641 by Mike McCrea, on Flickr

North Carolina. Sometimes, especially if you screw up the tides, the only choice is to drag the loaded boat across shallow sandy water. Dragging a loaded canoe across a sandy bottom in two inches of water for quarter mile isn’t abrasive abusive on the stem is it? Asking for a friend.

P2180691 by Mike McCrea, on Flickr

North Carolina again I think, but could be anywhere tidal. Oyster bars at low tide. That’ll put a hurting on your bottom if you run across it when barely submerged. A few wind riffles and a little glare and you’ll first know you’ve found an oyster bar when the hull goes “SKREESKRAAASKREEE”. Oops, too late.

P2210735 by Mike McCrea, on Flickr

Maryland. Unseen mussels at high tide are just as bad for your bottom, or if they are thickly encrusted at the camp landing at low tide. But they are tasty (pluck them off the bank at low tide, rinse them in a bucket of clean tidal water to filter out a couple times first, steam them open over a campfire, add them to a can of clam chowder. You remembered to bring Sherry and Oyster Crackers right?

P3020144 by Mike McCrea, on Flickr

Not shown; worm rock, shale banks, limestone, rocky river ledges that knick the stern when dropping over, dragging the canoe across yet another damn beaver dam, or my local homeriver, which is often shallow gravel bar scrapey in spots.
 
Joined
Jun 12, 2014
Messages
3,513
Reaction score
709
Location
NW Iowa
You did a nicely dense pattern with the scratches, even up past the waterline. The diagonal and horizontal ones must have been exciting.

Thankfully many of the sideways scratches didn't occur in rapids. A lot of those came from dragging a loaded or partially loaded canoe sideways up onto a rock landing or loading a canoe on the rocks and then sliding it down into the water. Or from being beat against shoreline rocks on a windy landing before I could get out.

On a tough landing I'd challenge the boat to a game of rock, paper, scissors to see if I was going to jump into cold thigh deep water or if the boat would take a few dings while I climbed up on the rocks. I usually played paper and the boat almost always chose rock.

I will admit however to a few occasions where I found myself hung up and sliding over an unseen rock in current.

A couple hours in the shop had the boat looking good again so no worries:

20161128_002 by Alan, on Flickr

Up close of some filled scratches:

20161128_003 by Alan, on Flickr

Alan
 
Joined
Dec 25, 2017
Messages
458
Reaction score
204
Location
Hogtown
Here are the results of my 2014 trip on the Natashquan! The skip fudgy kevlar felt skid plate was old but intact when I started that trip, this is what happens when you do 100km of upstream dragging fully loaded over Class III rapids

skid_burn.jpg
 
Joined
Feb 14, 2015
Messages
3,899
Reaction score
659
Location
Iowa
Here are the results of my 2014 trip on the Natashquan! The skip fudgy kevlar felt skid plate was old but intact when I started that trip, this is what happens when you do 100km of upstream dragging fully loaded over Class III rapids


Looks like you just tied a rope on the deck and drug ithe canoe down a Gravel road !

Those wrinkles in the Kevlar felt didn't help with speed much either !
 
Joined
Dec 25, 2017
Messages
458
Reaction score
204
Location
Hogtown
Skid plates were installed by the original owner. When I bought it (Swift Raven) it was in excellent used condition (light hull scratches only). This boat took some serious punishment even before the Natashquan trip including an unmanned journey through a 2km Class 5 & 4 on the George River. If it only needed skid plates I'd fix it but the hull bottom has numerous long cracks needing attention, all the cracks are in the exterior layer except one small one where a d-ring was glued on.

raven1.jpg

raven3.jpgraven4.jpg
raven6.jpg
raven7.jpgraven8.jpg
 

Attachments

  • raven4.jpg
    raven4.jpg
    47.9 KB · Views: 0
G

Guest

Guest

In Memoriam: Skip Fudgy, heroically sacrificing its life so that the stems could live to float another day.
 
Joined
Nov 29, 2012
Messages
629
Reaction score
172
Location
southwest Indiana
I have installed skid plates on one or both ends of around 18-20 canoes. In every case there was a good reason to do so. Most of these were Royalex boats but I have also applied them to a couple of composite hulls and one three-layer rotomolded polyethylene boat.

I have personally seen scores of Royalex canoes that have suffered stem abrasion into the foam core. If I added to that the photographs of Royalex canoes that I have seen with extensive abrasion damage at or near the stems, the number would probably exceed 100.

About 12 or so of the boats that I applied skid plates to were Royalex canoes owned by a nature conservatory that did guided canoe day trips on lakes or local creeks that I used to do volunteer work for. None of these trips were done on anything remotely resembling whitewater or rocky streams. The boats were actually all purchased new. Unfortunately, the lakes had concrete boat ramps. Despite repeated instructions by the guides not to grind the stems up on the ramps when landing, the clients repeatedly did so whenever they had the chance. Often there were just two or three guides and up to 16 boats, so it simply wasn't always possible to be present and policing people as they landed. It was commonplace for these boats to suffer abrasion damage down into the foam core within 3-4 years of being purchased new even though the stems got grounded only once per trip. I did not apply skid plates to the boats unless and until abrasion damage into the core had occurred or until the outer solid layer of ABS had become so thinned out that erosion into the core was imminent.

One of the boats I applied skid plates to was an old three layer poly livery canoe that had sustained erosion into the foam core over a length of about 2-3 feet at each stem. This boat required a great deal of repair efforts above and beyond application of skid plates, but when all the exposed foam core was filled in and covered with S Fiberglass, I applied Dynel skid plates over the stem areas.

Of the boats I have personally owned and applied skid plates to, in some cases these were whitewater boats that had had Kevlar felt plates applied to at some point in time that were now breaking off in great, big chunks. Removing those almost always resulted in denuding a sizable area of Royalex of the outer vinyl and there was usually also some damage to the ABS. Applying a better skid plate was always the most expedient way of dealing with this. I also applied skid plates to a few composite boats, one of which was a whitewater hull and one a downriver racing hull, both of which had sustained quite significant stem damage during prior ownership.

I have never applied a skid plate over a boat with no stem damage. I have used both Dynel and S Fiberglass with good results, and I do mix graphite powder into the epoxy.
 
Joined
Jun 22, 2022
Messages
1
Reaction score
0
Cliff J, JUST PURCHASED THIS 1999 MODEL MOHAWK 14 odyssey.. I will not be doing any WW intentionally. Ozark streams and rivers. The stems need something done. Your recommendations of a previous post will be fine. I'm handy at doing stuff. Farm boys are useful.
 

Attachments

  • IMG_20220621_102743512_HDR.jpg
    IMG_20220621_102743512_HDR.jpg
    204.6 KB · Views: 12
  • IMG_20220621_102732620_HDR.jpg
    IMG_20220621_102732620_HDR.jpg
    190.2 KB · Views: 12
  • IMG_20220621_102524030_HDR.jpg
    IMG_20220621_102524030_HDR.jpg
    195.5 KB · Views: 12
Joined
Nov 29, 2012
Messages
629
Reaction score
172
Location
southwest Indiana
Cliff J, JUST PURCHASED THIS 1999 MODEL MOHAWK 14 odyssey.. I will not be doing any WW intentionally. Ozark streams and rivers. The stems need something done. Your recommendations of a previous post will be fine. I'm handy at doing stuff. Farm boys are useful.
The stems really don't look that bad. I would check that largest area where the green vinyl has worn off exposing the tan ABS layer by pushing in with your thumb. If it feels soft relative to the surrounding hull then it has been thinned out be abrasion or weakened by photodegradation.

If it does not you might just paint the exposed areas of ABS with some green paint and get on with paddling. But if you do choose to install abrasion plates a single layer of 5 ounce/square yard plain weave Dynel fabric, or 6 ounce/square yard plain weave S fiberglass should be all you need. No need for multiple layers of Kevlar fabric plus fiberglass.
 
Joined
Jul 6, 2021
Messages
643
Reaction score
524
Location
The Hereford Zone along the Mason-Dixon Line
But if you do choose to install abrasion plates a single layer of 5 ounce/square yard plain weave Dynel fabric, or 6 ounce/square yard plain weave S fiberglass should be all you need. No need for multiple layers of Kevlar fabric plus fiberglass

What Pete said, but if you use a single layer of 5oz Dynel it is several times as abrasion resistant as S-glass. It is also less prone to strays and frays when wetting out.

Dynel is incredibly abrasion resistant. I did a bunch of experiments with it, but the most revealing was a guy on the GlenL site who did a simple experiment. He epoxied 6oz fiberglass and 5.5oz Dynel fabric and, once cured, scraped at them with the corner of a 5lb fire brick. It took 60 some swipes to cut all the way through the glass. He stopped at 250 swipes on the Dynel, still not cut through.

Dynel, a material recommendation recurring across three pages of this thread, has amazing abrasion resistance. CJ’s kevlar or multi-layer bias glass is, how to put this gently, yesterday’s skid plate news.

For an aesthetically pleasing skid plate you could tint the epoxy mix to “match” the hull, so the cloth was color impregnated. Or use black pigment and a teaspoon of graphite powder.

FWIW, our Mohawk Odyssey 14 is somewhere in this thread, with Dynel skid plates.

NOTE: It is necessary to use release treated peel ply over expoxied Dynel, otherwise it will swell and become rough surfaced. But the results, under peel ply compression, are worth the effort. This is a broad Dynel skid plate on a blunt nosed RX canoe that was beginning to show wear on the vinyl skin.

P4290006 by Mike McCrea, on Flickr

I’d be tempted to paddle the canoe until you see the perhaps different wear areas on the bow and stern, and use that wear area as a guide for where to protect. If you paint it as a temporary measure you’ll need to sand off the paint, so the epoxy is stuck to the hull, not just a layer of paint.
 
Top