Duane wrote: <SNIP> <<The bulkheads in the plastic VCP Skerray I recently sold didn't leak, and they where the welded in plastic type. >> As someone later pointed out some of these welded in bulkheads have failed catastrophically. I think they were the earliest ones, I hope VCP has the problem solved. If I was looking at a used one I'd want to know the details of what the problem was and if, when and how it was solved. I have seen a glued in foam bulkhead blown out of the bow of a double fiberglass kayak that was in the surf. The early ABS glued in place bulkheads (in glass kayaks) degraded rapidly in the sun and became very brittle and easily punched through by accident. Later ones have a vinyl (I believe) layer bonded on the surface of the ABS core to protect it from the sun. <SNIP> <<The only reason plastic kayaks may have leaking bulkheads more often is because of the abuse these kayaks take. Many of them are very old and have been stacked, sat on, stored improperly, and left out side to weather and bake in the sun, while fiberglass kayaks are treated like precious china. All kinds of kayaks have leaking problems. There were recent posts on this list about an all mighty fiberglass Romany having a leaking skeg box, and there have been some posts about leaking seams in a variety fiberglass kayaks.>> While many kayaks leak for various reasons it isn't only abuse that makes plastic kayaks with glued in bulkheads so prone to leak. Polyethylene is a very difficult material to bond to. That combined with the often soft flexibility of the material (testing the limits of the bonds) means that the statement of one retailer (when asked the security of the bulkheads in the plastic kayaks he sold)"guaranteed to leak in a week" was not a joke but a statement of fact. <Plastic kayaks, and the bulkheads in them, don't deserve the bad rap they keep getting.> I don't think the bad rappers are making up the stories I hear (or the dead feeling I get paddling one--or the difficulty I have keeping a spraydeck on some in the surf). As to how plastic kayaks and glass kayaks are treated, people tend to treat things in a way that reflects there worth to them. A well made glass kayak is pound for pound as tough as an equal sized plastic kayak and after ten years of aging and a little sun will be far stronger. Most glass kayak buyers want to use the extra stiffness of glass to save on weight (rather than be tougher) and the manufacturers try to comply so they will sell them what they want as best they can. The market is driven by the customers wishes often in the face of the manufacturers better judgment. Plastic kayaks could be made lighter but they would then either be too soft and flexible or if made stiffer likely be too brittle (with no fiber structure holding them together). I have considered making a plastic surf/play kayak and think there are some advantages to plastic other than price for certain functions especially for short lifespan kayaks such as for whitewater or big surf and ocean rock garden bashing. Making the kayak more affordable increases the market size and plastic kayaks can be popped out of a mold with less than an hour between them so they can truly be mass produced. Don't know if this will ever happen though, as things stand now just not enough hours in the day to put much effort into it. I do want to make it clear that I am not anti-plastic but just want to use the best materials for the job at hand whatever that may be. 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/ ***************************************************************************
Matt Broze has written quite a mouthful on this subject just now that I won't repeat. It confirms what I know directly and have heard from reliable witnesses. Namely that the nature of polyethylene makes it difficult to get things to adhere to it; that foam bulkheads in any kind of boat, fiberglass or plastic, are subject to breakdown over time, etc. I stick by my earlier statement: If paddling a plastic boat, do yourself the safety favor of keeping inflated air bags in the bulkheaded compartments. It is by way of wearing suspenders and a belt and good general advice for any thing. For example, I know that Feathercraft when it introduced sea socks didn't say anything in its literature about using airbags as well. Now it does say to use _both_. A friend of mine who has a small electric pump for his folding kayak, carries it in a bailing bucket so that, one way or another, he will be able to bail if he has to. BTW, please don't take this as knocking plastic kayaks. They are a lot better than people give them credit for. If it weren't for that first Chinook coming out in the mid-1980s, the sea kayaking phenomenon would have been a sliver of its current self. They paddle well enough for most people and some of the models, like the Sea Lion, are very fast. >From my point of view, the serious downside of the boats (other than weight) are two, one correctable the other not so. The correctable one is the question of bulkheads...use airbags. The non-correctable one is lack of a long life. The boats do get brittle with time and are not going to last anywhere as long as a fiberglass boat. You can extend the life by storing carefully and not dragging a plastic boat over rocks and logs, maybe even nourish the surface to keep it from drying out. Perhaps in our disposable society today, this weakness is not seen as one. ralph diaz -- ----------------------------------------------------------------------- Ralph Diaz . . . Folding Kayaker newsletter PO Box 0754, New York, NY 10024 Tel: 212-724-5069; E-mail: rdiaz_at_ix.netcom.com "Where's your sea kayak?"----"It's in the bag." ----------------------------------------------------------------------- *************************************************************************** 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/ ***************************************************************************
What are the warning signs of breakdown of foam bulkheads? Is this something I should look at replacing every 3 - 5 years? Having a bulkhead failure with the rear full of camping gear would be a royal pain at best. -----Original Message----- From: ralph diaz <rdiaz_at_ix.netcom.com> To: Matt Broze <mkayaks_at_oz.net> Cc: Paddlewise <paddlewise_at_lists.intelenet.net> Date: Thursday, February 03, 2000 9:12 AM Subject: Re: [Paddlewise] Swamped rear compartment-Plastic >Matt Broze has written quite a mouthful on this subject just now that I >won't repeat. It confirms what I know directly and have heard from >reliable witnesses. Namely that the nature of polyethylene makes it >difficult to get things to adhere to it; that foam bulkheads in any kind >of boat, fiberglass or plastic, are subject to breakdown over time, etc. > *************************************************************************** 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/ ***************************************************************************
On Feb 3rd Ralph Diaz wrote: <<From my point of view, the serious downside of the boats (other than weight) are two, one correctable the other not so. The correctable one is the question of bulkheads...use airbags. The non-correctable one is lack of a long life. The boats do get brittle with time and are not going to last anywhere as long as a fiberglass boat. You can extend the life by storing carefully and not dragging a plastic boat over rocks and logs, maybe even nourish the surface to keep it from drying out. Perhaps in our disposable society today, this weakness is not seen as one.>> I agree with all of this, but I would add one more way to extend the life of a plastic boat and that it to periodically apply some UV protectant such as Armorall. I have some plastic boats that are 7 years old and they haven't faded at all (one of the sure signs that Mr. Sun is doing harm). Cheers from UV central, Dave Dave Williams dave_at_paddleasia.com http://paddleasia.com Phuket, Thailand *************************************************************************** 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/ ***************************************************************************
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