Keel protection - Wharram Builders and Friends2024-03-29T09:53:02Zhttp://wharrambuilders.ning.com/forum/topics/keel-protection?commentId=2195841%3AComment%3A18445&feed=yes&xn_auth=noI also have to replace keel s…tag:wharrambuilders.ning.com,2018-03-27:2195841:Comment:1593922018-03-27T05:16:57.034ZEmil Gaigherhttp://wharrambuilders.ning.com/profile/EmilGaigher
<p>I also have to replace keel strip as original hardwood ? glued on 90% gone and rotten. Keel still very good underneath , no water penetration or sift spots.</p>
<p>After reading all posts I am thinking why not ad a srip of polyethylene , routed to contour of keel bottom by glassing over with a few layers of glass going some distance up the keel , then when starting to gell ada second , sacrificial strip by screwing with stainless screws into first layer ( carefull not to penetrate into…</p>
<p>I also have to replace keel strip as original hardwood ? glued on 90% gone and rotten. Keel still very good underneath , no water penetration or sift spots.</p>
<p>After reading all posts I am thinking why not ad a srip of polyethylene , routed to contour of keel bottom by glassing over with a few layers of glass going some distance up the keel , then when starting to gell ada second , sacrificial strip by screwing with stainless screws into first layer ( carefull not to penetrate into original keel) of poly. Thiswill then clamp unto soft epoxy and mould a ferfect fit. One could then also add cheeck strips extending from bottom of bottom strip extending past top strip say 5 cm up the keel, screwed onto both strips again while epoxy is soft to mould a nice seating, providing more protection anda degree of mechanical bonding to keel. No rot , light , slippy , no corrosion betweem metal and screws , easy to replace by using original screw holes and not to expensive compared to kevlar brass etc. , no antifouling needed.</p>
<p>Thoughts ?..</p> Hi there
I have used silica…tag:wharrambuilders.ning.com,2015-05-29:2195841:Comment:1306332015-05-29T06:15:53.479ZBrett Parkerhttp://wharrambuilders.ning.com/profile/BrettParker
<p>Hi there</p>
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<p>I have used silica flour(finely ground up sand) and epoxy. I am very happy with this using it on the bottom of my keels, skegs and rudders. I also applied it a little way up the keel(around 80 mm) because the keels sink down into the sand and can come in contacts with all sorts of things wanting to damage your keels</p>
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<p>The keels were already heavily glassed. This was keyed. I glued on some little spacing blocks to the required thickness I wanted.(approx…</p>
<p>Hi there</p>
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<p>I have used silica flour(finely ground up sand) and epoxy. I am very happy with this using it on the bottom of my keels, skegs and rudders. I also applied it a little way up the keel(around 80 mm) because the keels sink down into the sand and can come in contacts with all sorts of things wanting to damage your keels</p>
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<p>The keels were already heavily glassed. This was keyed. I glued on some little spacing blocks to the required thickness I wanted.(approx 12mm) Once set I used a strip of hardboard (the width of the keel) as a former. I put polythene tape on the length of the former and prearranged blocks and wedges to hold onto the keel while it dried. I firstly worked glue into the keel, then mixed up a really thick brew of silica flour and epoxy( it needs to be really thick because it is very heavy and you want to eliminate sag. You can always fill later if you do get sag) I applied this to the hardboard strip and placed it onto the keel. I then held it in place with the blocks and wedges and trowled off the excess once the strip was firmly fixed.</p>
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<p>This can be done in manageable sections depending if you are working alone etc. I went to a lot of trouble to do this but now I have complete peace of mind drying out in coral, shells or sand with stones. I coule actually dry out on a boat ramp if needed but I havn't needed to and a bottom with a bit of give is a more sensible approach. I used this on my T 30. I have sold this boat to good friends and know it is in great shape and plan to do the same to my new (used) T 38. Lastly no screwing into the keel!!!!</p>
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<p>Good luck Brett</p>
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<p>Do any sanding /grinding as soon as poss as this stuff is extremely difficult to sand. I also used a tiling trowel (with the little v's on its edge) to apply to the sides of the keel, skeg and rudder. As soon as this had tacked off I applied more to fill the v's</p> Oh, I wanted to share this Ch…tag:wharrambuilders.ning.com,2015-05-27:2195841:Comment:1303852015-05-27T14:56:28.873Zdennis schneiderhttp://wharrambuilders.ning.com/profile/dennisschneider
<p>Oh, I wanted to share this Chinese source with you: Ningbo Seawell Marine, Zhejiang, China, contact: "Lily", tel; 0086-18094544332. They have a large boat assessories catalogue; ex. ABS rectangular portholes, $27(you could do much better incountry). So you're building a Tiki 21; then you only need maybe 20 gal epoxy. Just don't get obssessed with the ply grade...(Malaheursment, il y avait 50 annee, depuis j' apprendu lections en francais, donc je lis bien votre idees...les francaises avant…</p>
<p>Oh, I wanted to share this Chinese source with you: Ningbo Seawell Marine, Zhejiang, China, contact: "Lily", tel; 0086-18094544332. They have a large boat assessories catalogue; ex. ABS rectangular portholes, $27(you could do much better incountry). So you're building a Tiki 21; then you only need maybe 20 gal epoxy. Just don't get obssessed with the ply grade...(Malaheursment, il y avait 50 annee, depuis j' apprendu lections en francais, donc je lis bien votre idees...les francaises avant le plus belle histoire en multicoques, n'est pas?!</p> Dennis, I am sourcing the mat…tag:wharrambuilders.ning.com,2015-05-27:2195841:Comment:1304652015-05-27T13:51:32.985ZÉric Bouvéronhttp://wharrambuilders.ning.com/profile/Bouveron
Dennis, I am sourcing the materials now. I'm in Hong Kong, and will built in mainland China. Start hopefully by the end of June.
Dennis, I am sourcing the materials now. I'm in Hong Kong, and will built in mainland China. Start hopefully by the end of June. Hi; when you get to that poin…tag:wharrambuilders.ning.com,2015-05-27:2195841:Comment:1304642015-05-27T11:40:11.085Zdennis schneiderhttp://wharrambuilders.ning.com/profile/dennisschneider
<p>Hi; when you get to that point, consider the cheaper - and simpler - solution which Hans used: metal strips (I used stainless 304, 2cmx3mm) encased in a couple layers of epoxy/cloth). Kevlar doesn't protect against impact...Oh, and yeah, what's keeping you from getting started?</p>
<p>Hi; when you get to that point, consider the cheaper - and simpler - solution which Hans used: metal strips (I used stainless 304, 2cmx3mm) encased in a couple layers of epoxy/cloth). Kevlar doesn't protect against impact...Oh, and yeah, what's keeping you from getting started?</p> Frank,
I am not -yet- a build…tag:wharrambuilders.ning.com,2015-05-27:2195841:Comment:1306262015-05-27T06:14:59.617ZÉric Bouvéronhttp://wharrambuilders.ning.com/profile/Bouveron
Frank,<br />
I am not -yet- a builder, but I am already considering aramide / kevlar as a reinforcment for the bottom of the hull. I am not really entousiastic about putting screws in the wood at this place.<br />
However, I have never used kevlar, and don't relly know if it is suitable in this situation.<br />
Éric
Frank,<br />
I am not -yet- a builder, but I am already considering aramide / kevlar as a reinforcment for the bottom of the hull. I am not really entousiastic about putting screws in the wood at this place.<br />
However, I have never used kevlar, and don't relly know if it is suitable in this situation.<br />
Éric Hi Pat: What Hans means by "c…tag:wharrambuilders.ning.com,2015-05-26:2195841:Comment:1306252015-05-26T16:26:20.777Zdennis schneiderhttp://wharrambuilders.ning.com/profile/dennisschneider
<p>Hi Pat: What Hans means by "collision shoot" is the German word for 'bulkhead' (schott).</p>
<p>Hi Pat: What Hans means by "collision shoot" is the German word for 'bulkhead' (schott).</p> Pat Ross said:
"i meet 2 GF…tag:wharrambuilders.ning.com,2015-05-26:2195841:Comment:1303782015-05-26T16:24:32.930Zdennis schneiderhttp://wharrambuilders.ning.com/profile/dennisschneider
<p><br></br> <br></br> <cite>Pat Ross said:</cite></p>
<blockquote cite="http://wharrambuilders.ning.com/forum/topics/keel-protection?id=2195841%3ATopic%3A9286&page=3#2195841Comment84162"><div><div class="xg_user_generated"><p>"i meet 2 GFK catamarans which hit a log during knight sailing. holes in the hull and bended shafts.. a simple collision shoot in the front helps a lot."</p>
<p>I have already had this experience with a Dead Head in rive in skinny water, that is what has started my interest…</p>
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<p><br/> <br/> <cite>Pat Ross said:</cite></p>
<blockquote cite="http://wharrambuilders.ning.com/forum/topics/keel-protection?id=2195841%3ATopic%3A9286&page=3#2195841Comment84162"><div><div class="xg_user_generated"><p>"i meet 2 GFK catamarans which hit a log during knight sailing. holes in the hull and bended shafts.. a simple collision shoot in the front helps a lot."</p>
<p>I have already had this experience with a Dead Head in rive in skinny water, that is what has started my interest in understanding how Kevlar may be helpful.</p>
<p>I am not familiar with a "Collision Shoot" or are we using different terms for the same thing "Water tight Collision Bulkheads" maybe even two in each hull and one in each hull on the stern?</p>
<p>Pat</p>
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</blockquote> What I did on a small cat was…tag:wharrambuilders.ning.com,2014-06-10:2195841:Comment:1183232014-06-10T15:29:52.593ZTam Dlhttp://wharrambuilders.ning.com/profile/TamDl
<p>What I did on a small cat was to build up epoxy to the thickness the screws require to hold the metal strips, but without penetrating into the wood. This uses a lot of epoxy, but it does ensure no wood gets penetrated. I based the technique on plaster work where moldings are applied by means of a screed and cross sectional profiles that are dragged through the plaster. Worked great. When the epoxy was a green cure I glassed it. Then I hardware bonded the strips. Still not sure metal is…</p>
<p>What I did on a small cat was to build up epoxy to the thickness the screws require to hold the metal strips, but without penetrating into the wood. This uses a lot of epoxy, but it does ensure no wood gets penetrated. I based the technique on plaster work where moldings are applied by means of a screed and cross sectional profiles that are dragged through the plaster. Worked great. When the epoxy was a green cure I glassed it. Then I hardware bonded the strips. Still not sure metal is the answer, but if I was doing it again I would do something similar. In this case I needed the directional control of keel strips, I just didn't want them to be made of wood, and a maintenance problem. Wharram scantling call for relatively huge amounts of epoxy in the keel area, so it is really only bad planing if during the process, one ends up with a situation where screws that penetrate the keel run into wood. Since no strip keel is required, perhaps after turn over one could just rip a slot the length of the external keel and fill that with epoxy then glass in accordance with the normal schedule. That way when the screws go up, they don't tie into wood, with the possibility of essentially infusing the whole hull skin with water. Not suggesting metal is the best way to do this, just that if doing it, I would never take the risk of running into wood. Of course, standard hardware bonding routines already exist to deal with this problem, but in this case it might be better to plan for the contingency early.</p>
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<p>As far as UHMW is concerned it is said to be bondable, further research is needed to figure out how effective that would be in service. Apparently the usual flame process works, and allows epoxy bonding. There are also a wide range of PSA backed UHMW, which are intriguing, because they are getting something to stick. Sometimes an existing adhesive will bond with another glue, so epoxy adhesion to the existing glue might be worth asking about. This strategy works with other plastics like PVC.</p>
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<p><a href="http://www.tse-ok.com/index.php/airboat-bottom" target="_blank">http://www.tse-ok.com/index.php/airboat-bottom</a></p>
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<p><a href="http://www.washingtonflyfishing.com/forum/index.php?threads/uhmw-what-do-you-know-about-it.72779/" target="_blank">http://www.washingtonflyfishing.com/forum/index.php?threads/uhmw-what-do-you-know-about-it.72779/</a></p>
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<p><a href="http://www.reltekllc.com/adhesives-coatings.html#B45" target="_blank">http://www.reltekllc.com/adhesives-coatings.html#B45</a></p>
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<p><a href="http://www.washingtonflyfishing.com/forum/index.php?threads/uhmw-what-do-you-know-about-it.72779/" target="_blank">http://www.washingtonflyfishing.com/forum/index.php?threads/uhmw-what-do-you-know-about-it.72779/</a></p> It's not that it will crack,…tag:wharrambuilders.ning.com,2014-06-06:2195841:Comment:1182312014-06-06T20:48:48.214ZOmar M. Rashashhttp://wharrambuilders.ning.com/profile/OmarMRashash
<p>It's not that it will crack, the glued joint will simply fail. If you're going to experiment, this is probably the place to do it.</p>
<p>I was specifically taught to not use epoxy with white oak. Our lead boat building instructer was a fifth generation wooden boat builder out of New England. He practiced his trade through the period that included the introduction of epoxies into boat building. Too many questions exist to permit me to feel safe about using epoxy with white oak anywhere on a…</p>
<p>It's not that it will crack, the glued joint will simply fail. If you're going to experiment, this is probably the place to do it.</p>
<p>I was specifically taught to not use epoxy with white oak. Our lead boat building instructer was a fifth generation wooden boat builder out of New England. He practiced his trade through the period that included the introduction of epoxies into boat building. Too many questions exist to permit me to feel safe about using epoxy with white oak anywhere on a boat where the bond forms part of the structural integrity of the hull.<br/><br/><cite>Rune M. Christensen said:</cite></p>
<blockquote cite="http://wharrambuilders.ning.com/forum/topics/keel-protection?page=4&commentId=2195841%3AComment%3A118056&x=1#2195841Comment118056"><div><div class="xg_user_generated"><p>If some cracks develop, its not a big problem, unless the whole keel falls of. Then I will have to glue in a new one of different wood :)</p>
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