What???
Some plans call for not putting resin on all wood? For real?
If this is so, then I’d use caution about selecting those plans. If you’re making a boat out of wood and fiberglass, ALL wood surfaces need to be coated with epoxy. Not a heavy coat, but at least something to seal it.
BS 1088 grade marine plywood, which is what comes with the majority of kits, is very rot resistent. But no wood is completely impervious to water. None.
There are techniques to use get the most use with the least amount of resin. But not coating all wood surfaces with epoxy…that’s a bad idea. You’ll end up replacing that wood in a year.
What I and some other designers recommend is building a “starter boat” to get some practice with the materials and technique. What you invest in time and materials, you’ll save 2-fold on your next boat. There’s lots of small boat plans that are for out there.
I’m pretty sure she’s talking about…
… the fiberglass, not the epoxy. Two different animals.
Pikabike is a regular contributor over on the Kayak Builder’s forum who’s really learned her way around lots of topics in the past few months and now has quite a bit to offer herself.
Glenn
glass ,not resin
They all say to cover the okoume with epoxy,some vary in where the glass is applied. For example the CLC Cape Charles from 10yrs ago was advertised as weighing 38lbs compared to a Pygmy Golden Eye which was advertised as weighing 39lbs. Except that the Golden Eye was covered in 6oz cloth and could easily withstand a 200lb paddler in any rescue configuration and the Cape Charles without any deck glass reinforcements or under deck reinforcments would fail easily. As of three years ago the CLC Chesapeake now has 4oz deck glass and substantial hatch reinforcements,but there isn’t any under deck reinforcement or cloth on the aft compartment bottom panels,only tape on the joints.
If you reinforce the Chesapeake to have similar hull and deck strength as an Arctic Tern where it matters the Cheasapeake will weigh about 5lbs more. That means for the Chesapeake the interior bottom panels have glass on both sides in the compartments and not just the cockpit, deck reinforced to handle 200lb paddler in rough conditions which means 6oz deck glass and under deck reinforment on the aft deck and foredeck.
oops
I read and replied too fast. You are correct. She said glass. Was looking in 2 forums at the same time.
Appologies and embarassment.
The joy of paddling
your hand built boat on the water is a “trip”. I can only speak of Pygmy’s. I have built the Coho and the Osprey double. The previous poster that said you learn from the first boat and do a better job on the second is correct. It will be the little things upon which you improve. Also, the instructions will make more sense. I found several things that I tweaked a little from the instructions to make the work a little easier. I have only seen a couple of CLC’s and while they are attractive boats I personally don’t like the painted hulls and they are a little more high volume than Pygmy’s. Find all the websites that you can, read, read and read. Even the strip sites offer insight to working with epozy and varnishes. The Pygmy support is great.
We need to have a midwest wood boat building rendezvous sometime.
Happy building.
Joe
Caveat emptor
That 38 lb-39 lb thing makes me wonder if it was a calculated marketing ploy on the part of CLC.
I’m glad I put on the 2nd layer of hull glass. I got a good look at a Coho that the owner has paddled all over the place. It has a bunch of glass patches as trip mementos. Now I kinda laugh at obsessing over tool marks from sanding the epoxy…once it gets paddled I’ll be looking instead at more obvious scratches in the varnish!
of course it was
Given that the internet didn’t exist at the time and most builders weren’t paddlers going into coastal conditions with other paddlers little “discrepancies” like that could get discovered wayyyy down the line after the “builders honeymoon” was over. And the paddler/builder would have a great time building anyway and modify the basic kit according to his experience and be off the the next construction/kit. That’s what I did.
This page pretty much puts the rational in a nutshell:
http://www.clcboats.com/cambereddecks.php/cart_id=242bbc7926befdb7c25fa9600f9a03dc/
The two fellows holding a kayak while standing on a kayak might imply something,strong decks maybe,except actual stresses a kayak will be subjected to in heavy use. I don’t know about you but when I’ve gone to the beach I don’t stand on kayaks holding kayaks. Those fellows are standing on bulkheads and deck beams in a static state. You also don’t see the 6oz(not 4oz deck glass), the strip of 4" 9oz tape I put down the underside of the foredeck, or the doubled aft deck hatch stiffener. Which make THAT boat perfectly able to be used as a foot stool. As long as the guy in the back stands carefully. But it doesn’t show what happens in the aft compartment for a standard layup where there isn’t cloth between the 3" tape on the bottom hull panel. If you turn the hull over and press down with your hand behind the bulkhead about a foot and midpoint in the panels between the keel and chine you can make the wood elicit cracking sounds. So transporting the kayak on a cart there or entry/exit on uneven surfaces in sheltered water can put point stress in an area that has no cloth. It’s a minor thing that’s easily taken care of,if you know about it. Likewise in rescue practice (a dynamic activity unlike photographs) a 250lb paddler in a Chesapeake 18 climbing on the aft deck will be climbing on an aft deck that has substantial reinforcements at the hatch hole but the deck still only has 4oz deck glass and nothing underneath which actually isn’t sufficient for a big person in the space between the coaming and aft hatch. The cracking sound you could make on the hullbottom are with 6oz cloth on the exterior and nothing on the interior between the tape ,for the aft deck with a big guy putting his body weight down will be putting point pressure where there’s lighter glass yet. Of course it’s a minor thing that one can address with another strip of 4mmply and under deck glass, if you know about it.
In rescue practice(or real life) one doesn’t always keep the rescuees boat safely in ones lap and sometimes it gets turned over/tossed on the foredeck or lands on the thigh/deck area. With a bent deck with 4oz on top there is some flexing still possible,which practically speaking isn’t very meaningfull from a strength issue(glass decks can flex/crack),except that flexing/cracking opens the epoxy seal coat and allows water staining. I’ve done roll practice where the other paddlers bow hit my deck straight on near the cockpit and cracked through the 4oz glass and opened cracks in the unglassed wood on the inside which allow for waterstaining more than anything,4mmOkoume is tough stuff just the same. But you’re a lot less likely to have that occure with a paneled deck glassed in 6oz with 4oz on the interior. There’s no way a bent deck with 4oz on the exterior only can be as durable as a paneled deck with 6oz on the exterior and tape or cloth on the interior. I’ve used both in 5yrs of kayak instruction so my observations come from use. Which isn’t a big deal,unless you’re a bigger person intending on coastal use,and then you add up all the other “extra” reinforments and the boat ends up weighing about 4-8lbs more depending on how the reinforcements are done. Again this isn’t a big deal if you like how something looks.
Abstract point?
I respect your experience and balanced info Lee but there is a substantial difference between an impact on framed or (worse) tortured ply (bent into a camber) as in your rolling anecdote and a 200 pound paddler clambering around on a cambered deck in the water. I can severely damage the back of my violin with the erasure tip of a pencil in an impact hit or I can knock myself out with it’s superior rigid side. Yes, I can illicit craking sounds aplenty if I push here or there against a wood bulkhead or cambered one-piece deck while the boat is sitting on a trailor or laying on the beach. Or, I can clamber all over the thing when it’s in the water. Are you saying that you have experienced damage from a rescuer banging around the rescuees camber decked boat? Very interesting stuff here.
cambered deck gets beating
i dont get it, my experience is they are simple and elegant. yes they require a shear stringer so what. my wet shoes add as much weight and its an area that gets banged often. some agendas seem to be operating in this area of design.
obscure point
If a person is looking to optimize materials for weight and strength then those are details not found in catalog info/dimensions/price.
Yes I've seen more damage on a cambered deck Chesapeake kayak compared to a paneled deck kayak, and a flat aft deck with 4oz on the top and nothing underneath is insufficient for heavy people when a substantial portion of their body weight might be on a hand or some gear that is strapped on the aft deck and the persons chest/stomach is pressing it into the deck as they re-enter the cockpit.
Here's an example,,it's really pretty small and not critical but you know after you've spent hours glassing and laying down a few fill coats, sanded, and put on four layers of varnish you've spent some time making something,,it doesn't take much time to think about it in use. During rolling or rescues you often grab the bow of another kayak and do things with it (it's perpendicular to you on the water). When dragging/lifting/flipping a rescuees kayak during an assisted rescue it can bump right on the deck plyood by your thigh. During rolling practice you might have a friend spot you and they might get over zealous paddling straight into your kayak or you might get sloppy while holding their bow practicing hip snaps and let your boat rotate down onto their pointy bow (er,,why plywood boats shouldn't have sharp bows) and have the deck of your kayak impact the bow of their kayak. Sure some glass boats might have damage there too,,but we don't care about some plastic boat,,this is our boat we've spent $1000 and 4months making.
On the cambered deck boat with 4oz glass on the outside and nothing on the inside there is not the same resistance to damage as a paneled deck with glass on the outside and glass on the inside. Like I said it's a little thing and not as important as the aft deck or bottom panels in the aft compartment,,but when you hear the crunching sound and feel the raised grain on the interior and see the waterstains you notice it. I made a Ch18 with 6oz deck glass AND 4oz interior glass and it showed that kind of damage from hitting another kayaks bow at the deck near the thighs. I made a Coho with 4oz deck glass, 4oz interior glass with extra strips on the interior joints (6oz exterior and 9oz tape interior is standard)and it hasn't had that kind of damage. The Coho is 3yrs older and had much more use/abuse. Basically the paneled deck doesn't allow flexing.
What is on that cambered decks page is 180 degrees from reality and reflects a willful ignorance given that the aft deck is less cambered and gets most of the stresses compared to the foredeck:
"Are multi-chine decks stronger?
Because they must be ‘glassed (to hold them together), it's a common misconception that multi-chine decks are stronger. But a multi-chine deck lacks the inherent strength of the arch shape. If you want the strongest deck possible, fiberglass a true cambered deck (a $10 option on most CLC kits)."
Rear Deck…
Stopping for a lunch break a while back with mostly Kevlar boats, we were all beached and I was sitting on the rear deck of my Pygmy when comments were made that it must be a very strong boat. I was a little surprised at their concern and told them that the boat does not flex…
Now that I have a Kevlar boat I can understand their concern a the time… GH
different spots
That’s why I mention the lack of glass cloth in the aft compartment in the Chesapeake,if you’re sitting on the aft deck the pressure is going through to that part of the bottom panels where the standard glassing schedule recommends only 3" 9oz tape. That isn’t exactly unusual or rough use but if there’s a little rock pressing up it’ll crack the wood where there isn’t cloth on the relatively wide flat bottom panels behind the aft bulkhead.
The bottom panels of the Chesapeakes are wider and flatter than a comparable sized Arctic Tern or Merganser so the plywood is cantilevered between the reinforced joints for a larger distance making it easier to crack the unreinforced Okoume on the inside. Like my Express with numerous gelcoat cracks or your friends kevlar boats this isn’t a catastrophic thing,except the composite boats don’t have a dry porous core that discolors when wet. My take on it is that flexing plywood that allows cracking isn’t ideal. All that varnish and epoxy must be on there for a reason.
I shipped a Merganser 16 to a friend a couple years ago,when the truck arrived another fellow was receiving a Romany,I was showing off the kayak, kind proud of the booboos and overbuilt nature, using only 4oz cloth but doubled on the hull with cut strips for specific areas,but finally a kayak that when overbuilt wasn’t overweight,wieghed around 44bs,so I walked along the deck,didn’t matter. My friend lives in Atascadero so I wanted a kayak that could land on a rock beach with a messy landing and not be a problem.
10yrs ago I made a Patuxent 17 that had glass tape doubled in all kinds of areas,but the CLC advertising was adamant “no deck glass needed”,so the hull had doubled layers of 9oz 3" tape all over the chines (as instructed) and fillets as wide as the tape (like the drawings) and it weighed 55lbs. “hmmm, I guess I went overboard”…went paddling with a friend along the coast launching at Goat Rock/mouth of Russian River with his first time construction, a Golden Eye , similarly overbuilt,except his boat could handle rescues for a 225lb paddler with no problem,and mine couldn’t manage it for a 165lb paddler (damn I’ve put on weight)
The cosmetics of his boat were WAYYY rough,mine was slick on the outside and a bit gruesome on the inside. He was a big guy and launched it from a rock beach with 6" round boulders. I had overbuilt the hull in the chines and keel but there was still no cloth in areas of the bottom panels and no deck glass, as instructed.
Fast forward to working with CLC, over four years ago and right before they instituted 4oz deck glass and hatch ring reinforcements. I was a bit of a Cassandra telling the guys that they didn’t know how under built the CLC decks were or how the designs stacked up to what was showing up “out there”. “if you guys haven’t paddled in coastal conditions or owned/built other kayaks you don’t know how significant the difference is between a demo on the South River 100miles from the ocean and a surf launch in Maine or the Northwest”
“you’re an instructor, most people don’t do that” ,“if there was a problem we would have heard about it”. Even though all the origninal demo boats had waterstaining cracks in the decks. So I took everyone (except the CEO/designer and owners, figure that) out for the equivalent of an ACA basic course over two three hour periods. It was great fun. Two aft decks broke, four aft hatches broke, and all the decks made cracking sounds from a few assisted and solo rescues in flat water where the heaviest person was around 200lbs. This was the first time these boats and these people had done conventional rescues with these kayaks in the Chesapeake,in spring 2000. On the two kayaks with broken aft hatch and broken aft deck (in flat water) if that happened in coastal conditions with a heavy paddler the aft compartment would fill,this isn’t a little thing in my book, it’s someones life, lightly built composite boats that would crack and groan would not have flotation failures from gelcoat cracking. This experience didn’t raise red flags for the owners. It took a letter from me to the owner describing the scenario where a weakened hatch and an underbuilt aft deck could lead to loss of flotation in the aft compartment. In fact prior to that demonstration I was castigated for recomending extra reinforcments on the aft deck or hatches as it wasn’t mentioned in the manuals. In the mean time rebuilding aft hatches was a seasonal task. New Models and New Marketing was the priority,but no effort to reexamine the PROCESS that put those models into the market to begin with. A good example recently is the new WR18 where the CONCEPT of leaving in a forming bulkheads in the ends wasn’t thought a problem when it was released for production last fall. “ok,you can take them out” They are still learning about sea kayaks.
Shortly thereafter deck glass and hatch/ring reinforcements became standard for all sea kayak models. And still there was nothing different for a Ch18 that is designed for a 275lb paddler and a LT16 which is fine for a 130lb paddler. It’s kind of like they had to be dragged screaming to improvements,and would still only go 75% of the distance. That Ch18 HAS to be reinforced more for the very heavy paddler it’s designed for,but a first time builder wouldn’t know it reading the manual or marketing blurbs.
All the little details I’m mentioning aren’t significant for most folks and the decks are now substantially better (except for those exceptions)but if you’re looking for maximum durability with minimal materials/weight it’ll take a paneled deck with glass on the interior (just like a paneled hull)or more/heavier deck glass than 4oz. for the cambered deck and some builders (yours truly) started puting on under deck glass. Once you add up all that stuff,you get a heavier kayak.
Harsh indictments. Reverse Engineering.
Some tough indictments there Lee. I have wondered in the past about your feelings towards CLC. Extremely good information to know. Thank you for sharing your experiences and thanks for having the time and resources to test the cambered deck design to the extent you have. Every day I wish we had not moved to the city. I literaly have no room to build any more. I want to continue building though and will again some day and your notes are part of my thinking process now. I am of the opinion that something else can be done besides making a heavy composite boat. I have had good luck with cedars in various framing applications and if the grain is right, I envision a cambered deck with a multitude of cedar deck beams. Bare ounces (even fractionaly) in weight yet extremely rigid. It would still have the stress hazard in between the beams though but any time you make a composite sandwich with wood as the core the chance of cracking and/or seperation of materials can occur. Have you ever considered a 6mm deck with no glass? I know there would be bending and fitting challenges… There is a guy that did a 12 mm dugout that raises (in my mind) the question of reverse engineering. Monocoque construction using thin lightwieght ply’s for a WW1 bi-plane is one thing but applying these thin panels of ply to a boat that can take the stresses you have reminded us of is quite another. So the reverse engineering in my head asks why not go heavier ply and less weighty composites? A 6 hour canoe made of 1/4 inch ACX ply will give you rough bottom banging, small rock under the bottom resistance sand-it-smooth and re-paint it years of use (yours truly and the guy that bought it). Why can’t the same logic be applied to a good looking boat made of heavier ply and less epoxy soaked glass? I can’t wait to get the facilities to start my wild ideas again.
Thanks again.
you had to be there
Like I said for most folks this stuff is nit-picking if aesthetics and occasional use are the criteria but the experts should really be experts if they’re receiving money for their expertise and designs.
Regarding making a four panel kayak from 1/4" ply,it’s possible but you won’t have the same ding resistance as 6oz glass and the size of joining fillets/tape becomes a significant part of the design and weight. Someone out there made a glassed Cirrus with 1/4" ply and it’s around 60lbs. 45lbs is reasonable.
That’s kind of the conceptual bind CLC got into with the pre-glued sheer clamp construction as the design mixes up elements of structural frames and monocoque construction,without really determining what’s needed/not needed as the new designs came out. “stuff” just got added on. The flat deck Northbays got underdeck carlins because “deck glass isn’t needed”,so five years later the “racing” Paxs got under deck carlins becaue the flat aft deck Northbays had under deck carlins,except there isn’t a plywood kayak out there with those kinds of timbers. If you have glass on both sides you’ve taken care of a big part of the problem. The Pax18 with a glassed 3mm aft deck and underdeck carlins has cracks in the wood from the simple act of putting on and taking off the VCP hatch. It’s perfectly ok to make a very light racing boat,but stress rising cracks from removing a vcp hatch? Of course that leaves out why a VCP hatch on a kayak without usful interior space or access to a skeg that isn’t needed on a straight keeled kayak that doesn’t weathercock. Skegs are primarily for weathercocking kayaks,the Pax18 does not weathercock one bit and is hard to turn. Skegs make kayaks harder to turn.
The origninal Yare/capecharles didn’t have interior glass,then the Chesapeake got cockpit glass because waterstains were becoming evident in those boats a few years down the line. But the idea of re-considering the use of 3" 9oz tape was never considered except that the chines got one layer and not two of tape. But the cloth was layed RIGHT OVER the tape. And only in the cockpit.
After awhile you wonder,why am I paying $750 for this learning experience when the manufacturer isn’t learning from the experience the customers are having?
sure
I wouldn’t have made so many if it wasn’t fun.
Cloth on top of tape
Actually, putting cloth on top of tape might be OK, IF you feather the tape edges real smooth so that there are no raised edges to trap bubbles. I didn’t do that because I just wasn’t thinking well enough ahead, and because this extra layer was not addressed in the kit instructions. But now that I did it the icky way, I still think it could work if done properly.
great discussion!
As a designer, I always suspected how the heck they got their stuff so light. It’s nice to hear what I was thinking to myself was right.
Not nice to hear the issues some of the companies are leaving themselves open for. I think I’ll stick to having a little heavier designs but that can take a little abuse.
weights
in the beginning,was the number. Actually I gotta give CLC some brownie points for getting the weights to a realistic number now and Pygmy was giving bare bones hull numbers without hatches/bulkheads, but the fact was that 10yrs ago you could have a paddleable bare Pygmy hull for under 40lbs that was covered in 6oz glass and the Cape Charles had all kinds of weak spots with an unglassed deck that couldn’t withstand basic rescues,for 39lbs! . Once folks get started on stretching the truth, when business is good,it’s hard to stop or distinguish where it matters.
Hasn’t launched yet
The boat looks great, but I have yet to put it in the water.
what if you eliminated the tape?