Dave Kruger wrote: <Big snip> >>>Let's hear what folks who **have broken** boats have to say. (Except for Doug Lloyd -- I think Doug is proud of having broken his British heavy several times!) I'd like to know what model you broke, and how you did it.>>> <snip> My Nordkapp never broke up per say. It was the seams that let go. I replaced them with tape inside and out, using epoxy resin, and now it is "bommer" (as Roger puts it). Dave's Arluk split its seams on our Storm Island rescue trip, in heavy open-sea conditions - and he had inside and outside seams factory installed, but they were done in fiberglass. I think fiberglass seams can have limitations for boats that get abused. My point is, there is more to consider in all this, than just the overall construction/weight/layup factors. One more point here, is that heavy kayaks for recreational day-surfing might be considered somewhat hazardous. That heavy Romany can be a liability in surf. Back to seams: Then there's the "H" extrusion seam, but let's not go there! Another factor we often forget about in this ongoing debate about haevy vs light, is the plain durability of heavier boats - they just last longer (guess they have to because you drag them more upthe beach). Anyway, I'm not too proud of my British heavy right now, as I can hardly lift the darn thing onto my car. Groan! Sorry for taking the bite, Dave. BC'in Ya Doug Lloyd *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
I'm confused. What's the difference between a "taped" seam inside and out and a "fiberglass" seam inside and out? Bob ----- Original Message ----- From: "Doug Lloyd" <dlloyd_at_telus.net> To: <PaddleWise_at_lists.intelenet.net> Sent: Thursday, April 06, 2000 12:25 AM Subject: [Paddlewise] Breaking Boats > > My Nordkapp never broke up per say. It was the seams that let go. I > replaced them with tape inside and out, using epoxy resin, and now it is > "bommer" (as Roger puts it). Dave's Arluk split its seams on our Storm > Island rescue trip, in heavy open-sea conditions - and he had inside and > outside seams factory installed, but they were done in fiberglass. I think > fiberglass seams can have limitations for boats that get abused. *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
At 12:25 AM 4/6/00 -0700, Doug Lloyd wrote: > >Back to seams: Then there's the "H" extrusion seam, but let's not go there! Oh, why not? What don't you like about "H" seams? -- Wes *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
Wes Boyd wrote: > > At 12:25 AM 4/6/00 -0700, Doug Lloyd wrote: > > > > >Back to seams: Then there's the "H" extrusion seam, but let's not go there! > Oh, why not? What don't you like about "H" seams? The way they are done currently, only the inside is taped/glassed, IIRC. The extrusion forms the outside seam. Half the joining strength. Check out what Eddyline does -- not as strong as what Doug is describing. -- Dave Kruger Astoria, OR *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
Bob asks: >>I'm confused. What's the difference between a "taped" seam inside and out and a "fiberglass" seam inside and out?>> Dave Kruger responded: >>I think Doug means "polyester resin and glass" when he says "fiberglass" and means "epoxy and glass" when he says "taped." I think he favors the epoxy over the polyester. Perhaps Matt broze can help here, also.>> Correcto-mondo. Though what I really meant was "polyester resin taped (or some call it glassed) seams" don't hold up as well as "epoxy taped (or some call it glassed) seams" - IMHO, for boats subject to a lot of abuse. The only difference I was attempting to highlight was that epoxy can be a better resin to use with the fiberglass tape or matt, as it is stronger. There are strong opinions to counter this statement, but for me, having re-taped my seams and added outside seams, using epoxy resin, I have a confidence in my kayak unparalleled (pardon the pun) in my previous 20 years of boat abuse. I will try and get you an excerpt from VCP on their defense of inside only polyester resin taped seams. On a related note, my previous post did imply my dislike of "H" extruded seams. This was more to do with my high standard for hull-to-deck strength, rather than anything empirical. "H" seamed boats seem to be standing up fine, though I get reports of leakage. But on the matter of vacuumed bagged boats vs heavy Brit boats, I've seen and heard of many a "lighter-duty" vacuumed bagged boat suffering breakage in surf. Sorry, Nick, et al, Matt's point about adding an extra 10 (maybe 15) pounds is all too true. But it is not the vacume bagging at fault, just the lack of material that can result from too much emphasis on lightness. It is all a matter of balance and ordering your boat to suite your usage. Interestingly, my standard-duty fiberglass laid-up Lendal paddle from 1981 is still going strong, after years of substantial abuse, including broken blades (which have been replaced after surf misshaps, albeit with a shorter loom now after cutting off the old broken blades). The shaft is a bit heavy, but has never busted. On the other hand, a brand new standard-duty Lendal paddle I bought last year (same model, just 19 years newer, and vacuumed bagged I think) weighs a bit less, has a bit more flex - but snapped like a twig recently. Anecdotal evidence, yes, but none-the-less true. I only go lighter-weight now if the item/boat/etc is compensated for with more exotic materials. Of course, I paddle and buy gear to please myself, not meet other people's criteria, no matter what their status in the kayak fraternity. :-) BC in Ya Doug Lloyd *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
----- Original Message ----- From: Doug Lloyd <dlloyd_at_telus.net> Sent: Thursday, April 06, 2000 10:41 PM Subject: Re: [Paddlewise] Breaking Boats > > Correcto-mondo. Though what I really meant was "polyester resin taped (or > some call it glassed) seams" don't hold up as well as "epoxy taped (or some > call it glassed) seams" - IMHO, for boats subject to a lot of abuse. The > only difference I was attempting to highlight was that epoxy can be a > better resin to use with the fiberglass tape or matt, as it is stronger. > There are strong opinions to counter this statement, but for me, having > re-taped my seams and added outside seams, using epoxy resin, I have a > confidence in my kayak unparalleled (pardon the pun) in my previous 20 > years of boat abuse. I completely agree with Doug. Epoxi is so expensive here in Argentina I never tried it, but I know it´s stronger than polyester resins. I build my kayaks with a fiberglass taped seams inside and outside. In the first kayaks I used the woven fiberglass tapes you described ( I suppose ), but they delaminated with the use. So now I make my own "tape like" cutting slices of matt and glassing them all together in a chain like distribution along the joint. They sum 4 layers outside and 6 inside. Never delaminated again, my own kayak is heavy, 30kg, is 8 years old, has about 6000 miles paddled, some in heavy rouge seas surfing waves 4m high, landing on stony beaches, etc... and still report any leackage. But the best test was passed when while carried with a friend totaly loaded with about 70kg of cargo, it fell of my shoulder to the concreete floor without suffering any crack. I laminate both deck and hull alternating twoo 300 denniers matts, one 220 denier weave, one 300 denniers matt, and finnished with one #30 roving weave. I use isostalic polyester resin and isostalic gelcoat and not bacuum badged process. I should add I don´t build kayaks on a regular basis, they are made under request, so I don´t have a factory with industrial processes involved to optimize results. I am more like an artisan. Any coments or questions will be wellcome. I´m allways willing to learn. UNIÓN DE KAYAKISTAS DE TRAVESÍA Fernando López Arbarello uktkayak_at_uol.com.ar *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
<< Bob asks: >>I'm confused. What's the difference between a "taped" seam inside and out and a "fiberglass" seam inside and out?>> >> Bob, I think that you may know all of this, it is for P'wisers that are not familiar with the term "tape or taped" with reference to fiberglass construction. "Tape" may be a misnomer to the uninitiated. The "tape" itself is non adhesive and must be applied using resin. Polyester, vinylester or epoxy resins may be used. Two layers or more are recommended. Fiberglass tape comes in a variety of widths from 2-12 inches. It is generally made of 8 oz. fiberglass cloth, 8 oz. refers to the weight per square yard of the material. It is also available in carbon fiber or Kevlar. In the "H" channel situation, the "H" channel provides good registration of the hull and deck halves and a finished look to the outside joint between hull and deck. The structural integrity of the joint comes from the inside "taped"seam. Usually several layers of four inch tape and resin. Oh, this doesn't answer the original question. There may not be a difference between a "taped" seam inside and out and a "fiberglass" seam inside and out? Bruce McC WEO *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
Dave wrote: >>Matt, on a typical vacuum bagged layup, where are the "fold prone" areas? I recognize this will depend somewhat on the design, but if you could generalize some, it would help. I have reinforced the deck of my main touring yak (Eddyline Wind Dancer) aft of the rear hatch, and am thinking about adding a layer or two of epoxy/glass to the underside of the deck, forward of the cockpit, as well. Any other locations I should consider?<< It doesn't matter if it is vacuum bagged or hand laid the breaks will occur where the stresses concentrate. Most likely the damage will be on the deck as the deck is usually a lighter weight lay-up than the hull. Beyond that it depends on what causes the folding forces and where the particular kayak is most likely to fold. A big breaker buckling the deck from above will likely put stress cracks in the gelcoat (parallel to the length of the kayak) where the gelcoat is put under tension by the "frog croakering" in of the deck (usually above the seam where the deck transitions from sharper curve to flatter). If you stick one end of a kayak in the sand and pole-vault off the bottom as I have done on several occasions in dumping breakers the compression fracture (if it occurs) will most likely be a vertical crack a few inches long going across the curve of the deck just above the seam and it will occur about one half way between the end of the kayak and the next thing that makes the kayak stiff enough that it can't fold in that area (such as the cockpit or a hatch). The light surf reinforcements are mainly in the deck area curve just above the seams and from the reinforcing around the cockpit to within about 3 feet of the stern or bow. Your particular kayak may also have a problem with the curve of the bilges getting compression fractures as the flat hull slams down onto a small wave after getting airborne going out over a cresting wave. This will depend on the huskiness of the lay-up of your particular boat. If it is a lightweight or cored hull I'd stay out of the surf. A compression fracture usually busts up the gelcoat for a quarter inch around the crack. They are easy to patch on the inside but take a little work to make look like new again on the gelcoat side. Dave again: >>Also, is there a reference you can suggest for adapting vacuum bagging to a reinforcement job like this? I don't think my usual technique (wet out the glass with epoxy and squeegee the excess out) gives a very good job, especially when I want more than one layer of glass. (Usually let the resin get to the almost stiff phase before I lay on the second layer of glass, but sometimes I have tacked a second layer on top of a still-wet squeegee layer -- the glass moves around a lot.)<< Sand where you are going to add material and well beyond. use material that is the same or more flexible than the material in the kayak (so the patch doesn't flake off). (Note: sanding is not necessary with hand layed kayak unless it has a surface coat of a resin that fully cures put over the original lay-up--or the lay-up contained "surface agent"--explained below). I'd lay it up wet and with different sizes for each layer so the result is like a beveled edge (always try to avoid a large discontinuity in thickness over a short area that will create a stress riser). Lastly, I would cover the area with wax paper and smooth it and squeeze out the bubbles that you can. The waxed paper lets the resin cure hard on the inside surface and with a smoother surface (much more like the vacuum-bagging you started with). This not only makes a smoother surface but it is much easier to sand off the rough edges too. This is because being fully cured rather than gummy (air inhibited) on the surface, the sandpaper doesn't quickly gum up. If the wax paper trick is too difficult over that large an area get some "surface agent" (a liquid wax you mix with the resin that floats to the top and seals out the air so the surface can fully cure). Matt Broze http://www.marinerkayaks.com *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:33:12 PDT