Bill Gwynn Posted October 3, 2005 Share Posted October 3, 2005 10 of us set out from the northern end of Plum Island to go play in the current at the mouth of the Merrimack. Unfortunately our plan was not very well thought out and we arrived at pretty much slack high tide. We tried our best to catch what little surf we could find just off the end of the breakwater with little success. We decided it was a good time for a lunch break, and the landing at the very steep beach there was pretty exciting, and certainly entertaining to watch as each paddler showed off their indvidual acrobatic skills while landing. Paula had the best ride in. Just when she thought she had landed safely, here comes a big one. The look on her face was priceless as the wave collapsed right at her back. Of course, she rode it in prefectly straight with all the poise and grace of a lady. As we were enjoying our lunch, sun and friendly banter, we noticed a sand bar a little south of us a couple hundred yards off shore that was showing some promising breaking waves as the tide receded. It turned out to be a really good spot with waves coming in and breaking then refracting back for some really fun surfing, bracing, bongo sliding, capsizing, rolling, fun. I witnessed some very cool rides by all, I saw Alex's boat pointing straight up in the air, however, the event of the day was when Brad took a ride on an incoming and refracting wave right where they met. The force of the two waves meeting tossed him in the air, then on his return flight down landed with such force that it flexed his boat and actually cracked it amidships on both sides. It's the first time i've ever seen such damage that didn't invlove rocks or another boat. Needless to say, he will be brushing up on his glass and gelcoat skills. Great day, great paddling, great company, what more could you ask for. Pics can be seen at: http://www.kayakpics.com/gallery/100205 Quote Link to comment Share on other sites More sharing options...
Suz Posted October 3, 2005 Share Posted October 3, 2005 "Great day, great paddling, great company, what more could you ask for".... What more??? How about me being there! I stayed home and packed boxes instead of paddling. Even dropped off my boat in Salisbury to remove the temptation and lent three sets of blades out. I had lunch at the Salisbury side of the river and saw two paddlers heading to the mouth at about 1p.m that wasn't part of your group. They were moving so fast with the ebb towards the mouth but then I had to leave and get back to work. Hey- was the picture of the damage to the boat Brad's boat? If so, WOW - no contact with anything but stress to the hull from the wave. Suz Quote Link to comment Share on other sites More sharing options...
Bill Gwynn Posted October 3, 2005 Author Share Posted October 3, 2005 Yes, we did miss you Suz. The boat damage in the photo is of Brad's boat. It is pretty much the same on both sides of the boat exactly opposite each other. I had never seen or heard of such a thing happening. Quote Link to comment Share on other sites More sharing options...
EEL Posted October 3, 2005 Share Posted October 3, 2005 Did it actually fracture the fiberglass/epoxy layer, or did the hull flex just crack/shatter a section of the gelcoat? Was it on a bulkhead location? I suppose both are worrisome, but the former would get my attention very fast as it indicates a structural issue. Ed Lawson Quote Link to comment Share on other sites More sharing options...
scamlin Posted October 3, 2005 Share Posted October 3, 2005 Suz: Your blades had a good time on the break...and send you their regards. Scott Quote Link to comment Share on other sites More sharing options...
scamlin Posted October 3, 2005 Share Posted October 3, 2005 Hard to say, but in my opinion the outer layer of the fabric was frayed or broken. It gave when pressed with the end of a thumbnail. The cracks were not on a bulkhead or other internal structures: just the sides of the cockpit. A quick inspection of the inside of cockpit showed little or no damage to either gelcoat or fabric. With damage of this kind, damage to the glass fibers can be more extensive than you can see from the outside. Best to cut it out until you have hard, firm fabric on all sides. Scott Quote Link to comment Share on other sites More sharing options...
Paul Sylvester Posted October 3, 2005 Share Posted October 3, 2005 At the risk of opening up a can of worms............what kind of boat was it? Was it near the cheekplates? If so, could they have put pressure on the hull? Quote Link to comment Share on other sites More sharing options...
Nick Schade Posted October 3, 2005 Share Posted October 3, 2005 From the looks of the pictures, I would say that it is very unlikely that you could get that much gelcoat damage without having significant structural damage in the underlying fiberglass. Unfortunately, due to NDK propensity of using pigmented resin on the inside of the boat, even severe structural damage may not be visible from the inside. Quote Link to comment Share on other sites More sharing options...
Guest guest Posted October 4, 2005 Share Posted October 4, 2005 When I was about 19...we used to run a 20 foot water fall on the Watauga River on the TN - NC state line, it was called ''state line falls'' and back then we paddled epoxy glass/nylon whitewater boats that we built ourselves. The trick is to go off at the correct angle, hit bow down a bit and bounce... But one time, a kid with us said those famous last words we used down south...."Hey Y'all, watch this!!"... He paddled off the lip at full speed, jerked his shoulders back and landed flat on the hull, known today as a ''boof".....the whole boat folded up around his ears as his butt went thru the bottom. Quote Link to comment Share on other sites More sharing options...
Bill Gwynn Posted October 4, 2005 Author Share Posted October 4, 2005 It is a Valley Avocet with their standard glass layup. The damage is actually foward of the cheek plates, closer to where your knees are. Quote Link to comment Share on other sites More sharing options...
Suz Posted October 4, 2005 Share Posted October 4, 2005 Did you like the Mystic the best? They are my favorite for the surf. Suz Quote Link to comment Share on other sites More sharing options...
scamlin Posted October 4, 2005 Share Posted October 4, 2005 Nick: Actually it was a Valley Avocet, but still had pigmented resin on the interior. Scott Camlin Quote Link to comment Share on other sites More sharing options...
scamlin Posted October 4, 2005 Share Posted October 4, 2005 Paul: If I remember, it was a couple of inches forward of the front of the seat. Scott Quote Link to comment Share on other sites More sharing options...
Paul Sylvester Posted October 4, 2005 Share Posted October 4, 2005 I am with Ken, it sounds like stress from a fold. It will gain a little weight in the repair but should be fine. It is surprising that the ends caught enough water to do that kind of damage. Paul Quote Link to comment Share on other sites More sharing options...
Nick Schade Posted October 4, 2005 Share Posted October 4, 2005 I'm sorry for making the NDK assumption. But I would still make the assumption that in the areas where the gelcoat flaked off the outside that the glass has lost most of its strength. If the boat is going to be used where it might see similar forces again, I would want to completely replace that area of the boat. Quote Link to comment Share on other sites More sharing options...
Bill Gwynn Posted October 4, 2005 Author Share Posted October 4, 2005 I have been in contact with Valley regarding this incident, and they seem genuinely concerned about the damage and how it happened. It looks like they are going to have us deliver the boat to GRO/The Kayak Centre in RI to further evaluate the damage and determine if this may be covered under the warranty. I'm just waiting to hear back from either Valley or GRO. FYI, I recieved an email from Valley within 4 hours of sending them an email with a description of the damage and the way it happened, and a link to the photos. Quote Link to comment Share on other sites More sharing options...
Bill Gwynn Posted October 9, 2005 Author Share Posted October 9, 2005 I brought the damaged Avocet down to The Kayak Centre today. After several people looking at it, it was decided that the damage was done as I had described it. They went on to further decide that it shouldn't have happened, and replaced the boat under it's warranty. They gave us a 2005 glass Avocet that had been used a few times in some of their classes. The boat is actually as good as new, hardly a mark on it anywhere. We couldn't be more happy with the service provided to us by Valley and GRO. The best part was that today was Brad's birthday, and he couldn't of asked for a better present. Quote Link to comment Share on other sites More sharing options...
Suz Posted October 9, 2005 Share Posted October 9, 2005 Now that is a good news story as it was pretty depressing to hear that a boat could get damaged like that. It also says a lot about a company that would stand behind their boats that way! Way to go Valley and GRO! Suz Quote Link to comment Share on other sites More sharing options...
Nick Schade Posted October 9, 2005 Share Posted October 9, 2005 >Now that is a good news story as it was pretty depressing to >hear that a boat could get damaged like that. > Cue my rant about Chopped Strand Matte construction. There are several kayak manufacturers that use CSM to build their boats. While it is possible to do a good job or a shoddy job with this material, regardless of the skill of the labor doing the work, the result will be heavy and relatively fragile for its weight. Not only is the material brittle and heavy, it promotes poor workmanship and poor quality control because it is hard to inspect for quality issues. Mistakes are hard to see. This problem is further exacerbated by a tendency of manufacturers to use a pigmented resin on the inside of the boat. They do this because the CSM layup tends to be a little unsightly, even when under a layer of woven cloth, and the pigment looks a little better. This again causes quality control issues. Not only can't the buyer determine the quality of the layup, the builder can't either. Thus boats with flaws leave the factory, and customers buy them only to find out on the water if there is a problem. I am glad Valley and GRO stood by their product. Hopefully, the cost of this kind of issue will make them rethink how they build their otherwise fine boats. Quote Link to comment Share on other sites More sharing options...
scamlin Posted October 9, 2005 Share Posted October 9, 2005 Nick: With some trepidation given my limited knowledge of kayak materials and their characteristics, I believe the Brit's rationale for using chopped strand mat is not cheapness but rather stiffness. If I remember correctly, the random orienation of the fibers results in a stiffer layup for the weight. The British logic, right or wrong, is that in their conditions, very stiff boats are desireable for fending off rocks and supporting loaded boats during rescues. (I won't cite the third rationale for stiff boats--speed--as their weight would seem to preclude this advantage). To the extent CSM gives these characteristics to the hull and deck, its use is a design choice, not a cheap way out. Another potential characteristic for CSM may be better resistance to punctures. From an engineering and materials point of view, does CMS have an advantage for impact resistance compared with fabrics? My non-expert hunch is that a random orientation of mat would distribute impact better than woven fabric, but I really don't know and would welcome informed input. If so, is this what you mean by fragile? Or is it resistence to bending forces, such as the one the Avocet suffered? Your point about the disadvantages of CMS for quality control and pigmented resins for cosmetic reasons seem well taken, though the issue--as you point out--is not whether the layup can be done well but whether you or the builder can tell. Brits make a similar case for heavy gelcoat: a preference for the wearability on rough cobble and sharp rocks typical of British coastlines at the cost of the weight and tendency to chip. Again, if the design goal is resistance to abrasion, heavy gelcoat is a good solution. Whether it is worth it to you is another question. (An illustrative contrast would be my old kevlar Necky Arluk III, which weighs 43 lbs for an 23.5" x 18' boat. The layup is quite flexible, stiffened only by a wooden dowel glassed to the inside of the keel, a sharp entry and exit for the hull and a sharp peak on the foredeck. It has endured many scrapes, bumps and crashes without holing or major damage, but then I've not used it for the kind of surf and rock garden conditions and general abuse we often put our Brit boats through. The gelcoat is pretty thin and not surprisingly has worn through in many places. My point is that it had a different design philosophy and its own advantages and disadvantages.) My impression is the Brit philosophy to build a durable if not bombproof boat and not worry too much about weight. If that is the design objective, can you build a very stiff boat out of fabric? What would it weigh for a stiffness similar to CMS? It seems to me that is the apples-to-apples engineering question. I don't know the answer but imagine it is an empirical one. Scott Quote Link to comment Share on other sites More sharing options...
Paul Sylvester Posted October 10, 2005 Share Posted October 10, 2005 It is my understanding (and experience) that CS matt when holed will stay centralized and the damage will not travel.After seeing firsthand the rocks and conditions that the Brits and Welsh paddle in it makes good sense to me to be able to repair a simple hole rather than deal with a hole and a long crack down a hull. I am speaking more about kevlar vs CS matt and claim no expertise about the glass layups used by stateside manufacturers. When you combine Epoxy with glass layups in the stripper or S-n-G construction you do get a very tough boat for the weight.I have abused my wooden boats in many ways and never been disappointed in the beating that they would take for a given layup. But I do like my Brit boats........... Quote Link to comment Share on other sites More sharing options...
Bill Gwynn Posted October 10, 2005 Author Share Posted October 10, 2005 I was told that one reason CSM was used is that is does hole easily. In other words in a major impact it is better to have a boat get holed and minimize the area affected by the impact rather than have the impact affect a larger area as it would in a non CSM boat. When I crashed my Kevlar Valley boat into the rocks very hard the damage was significant in large areas all over the boat. It did not hole any where to many peoples surprise, but I did crack the rear bulkhead, broke the seam, and made a general mess of the whole boat. Some have said, had it been a standard lay-up Valley or NDK, the damage would have been more severe, but located in a smaller area ie. holed. I don't know if any of this is actually true, but it does seem to make sense. Quote Link to comment Share on other sites More sharing options...
bob budd Posted October 10, 2005 Share Posted October 10, 2005 I also admit to being less than expert but offer the following >...chopped strand mat...not cheapness but rather stiffness. If I >remember correctly, the random orienation of the fibers results in >a stiffer layup for the weight...a random orientation of mat would >distribute impact better than woven fabric As noted elsewhere chopped strand would localize a puncture but also localizes the "grain" of the mat and thus sacrifices stiffness. The chopped strand does not distribute impact along the woven fabric. >...gelcoat...wearability... Gelcoat serves primarily to protect the fiberglass from UV degradation and associated environmental factors. Quote Link to comment Share on other sites More sharing options...
Nick Schade Posted October 10, 2005 Share Posted October 10, 2005 I have heard the localized damage rationalization also. It sounds like something a manufacturer comes up with after the fact to explain the choice of inferior materials. Given a choice between a catastrophic failure in one small area and a softening of a larger area, I think the less severe but larger damage is less likely to be dangerous. It is easier to paddle an intact boat that has a soft patch than it is one with even a small hole but a flooded compartment. And presented with a CSM boat that failed in a large area when slapped around by what sounds like a fairly small wave I would start to question the whole logic of the rationalization. Kevlar does have a tendency to get soft after extended use and abuse, but sticking with glass while substituting woven cloth for CSM, you can make a boat that is lighter, stronger and less likely to get any damage what-so-ever. http://eteamz.active.com/paddleshop/albums...x.cfm?id=239260 has video of a guy whaling on a glass layup with a hammer. Don't try this with a CSM layup. And just for completeness: adding a nice thick layer of gelcoat to the already brittle CSM layup only makes it heavier, weaker and more likely to sustain severe damage. It does make it take longer to wear through, but not as well as added layers of woven glass. Quote Link to comment Share on other sites More sharing options...
Nick Schade Posted October 10, 2005 Share Posted October 10, 2005 >I also admit to being less than expert but offer the >following > >>...chopped strand mat...not cheapness but rather stiffness. If I >remember correctly, the random orienation of the fibers results in >a stiffer layup for the weight...a random orientation of mat would >>distribute impact better than woven fabric CSM maybe stiffer, but that is because the layup is thicker. Thicker -> stiffer. The reason the layup is thicker is because CSM is sort of "fluffy", i.e. it has a lot of space between the fibers. As a result a given weight of CSM absorbs a lot of resin and relatively speaking there is a small amount of glass for the weight of the boat. The bulk of the CSM makes it quite thick and thus stiff, it is not a result of fiber orientation. Stiff is good, if the material is strong enough to withstand the forces applied to it. Otherwise a flexible, resilient layup that bends gracefully may be able to distribute the load over a large area. As a result no one part of the boat will see high forces that are beyond the strength of the material. > >As noted elsewhere chopped strand would localize a puncture >but also localizes the "grain" of the mat and thus >sacrifices stiffness. The chopped strand does not >distribute impact along the woven fabric. Fiberglass boats are technically FRP "Fiberglass Reinforced Plastic." The whole purpose of adding any fiberglass at all to the plastic resin is to reinforce it. The way fiberglass does this is by distributing the load. If the glass does not do that, there is not much point in using it. You might as well just have a plastic boat, and there are better plastics for the job than polyester resin. Of course without the glass, hitting a polyester boat with a hammer would make a small, hammer head sized hole. If a small hole is desirable, eliminate the glass altogether. Obviously, this may cause other problems. > >>...gelcoat...wearability... > >Gelcoat serves primarily to protect the fiberglass from UV >degradation and associated environmental factors. In other words any more gelcoat than is strictly necessary to block the UV is superfluous. A couple mils is sufficient for UV protection. If there is enough gelcoat that it flakes off or cracks when you hit something that is a good sign that there is more than is needed. That extra gelcoat actually weakens the boat because when it cracks it causes localized stress in the glass below it. If the gelcoat is thin, it can bend without cracking or flaking off. If the gelcoat cracks, it shows that the gelcoat was trying to fill a structural role which it isn't suited to. Quote Link to comment Share on other sites More sharing options...
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