{"id":981,"date":"1999-11-30T00:00:00","date_gmt":"1999-11-30T05:00:00","guid":{"rendered":"https:\/\/setsail.com\/?p=981"},"modified":"2015-10-16T12:13:05","modified_gmt":"2015-10-16T17:13:05","slug":"aluminum-catamaran","status":"publish","type":"post","link":"https:\/\/setsail.com\/aluminum-catamaran\/","title":{"rendered":"Aluminum Catamaran"},"content":{"rendered":"<div class=\"question\">\n<p>Dear Sir, We plan to build an aluminum catamaran (sail) 47&#8242;, with round, relatively narrow (4&#8242;) hulls. We have several good alu-motorboat builders in the region&#8211;however no catamaran built here except the Osram IV which is a chaine hull. One builder would like to build the boat, if I would roll him the plates, one hullside 4x12x 8 1\/4 or 3\/16&#8211;He is welding nice motorboat hulls, nice seams etc&#8230; but how do I form the plates? I found one large rolling machine, but it&#8217;s outside and the rolls are very, very rusty &#8230; and what about the next step to get the compounded curve? I read about the English wheel, but that&#8217;s good only for steel, because the tracks are on the outside. The necessary (local) expansions of the prerolled aluminum sheet are pretty small, because of the narrow width of the hulls, I even can calculate it, but how to expand the metal???? Thanks for any advice, Christian <\/p>\n<\/div>\n<p><!--more--><\/p>\n<div class=\"answer\">\n<p>Hi Christian: You&#8217;ve asked a very difficult question. Any metal boatbuilder familiar with fabricating round hulls will know how to form your plates. With aluminum this is typically done with a hydraulic press, and simple wooden dies, rather than rollers (although rollers are sometimes used for some parts). This is very much an art and not a science&#8211;and if the builder with whom you are talking does not know how to do this, I would find one who does. Otherwise, you will have all sorts of arguments about what fits and what doesn&#8217;t and whose fault it is! Regards&#8211;Steve Dashew <\/p>\n<p align=\"center\"><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Dear Sir, We plan to build an aluminum catamaran (sail) 47&#8242;, with round, relatively narrow (4&#8242;) hulls. We have several <a class=\"read-more\" href=\"https:\/\/setsail.com\/aluminum-catamaran\/\">&#8230;Read More<\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17,10],"tags":[],"class_list":["post-981","post","type-post","status-publish","format-standard","hentry","category-yacht-construction-forum","category-tech-talk"],"_links":{"self":[{"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/posts\/981"}],"collection":[{"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/comments?post=981"}],"version-history":[{"count":1,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/posts\/981\/revisions"}],"predecessor-version":[{"id":36391,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/posts\/981\/revisions\/36391"}],"wp:attachment":[{"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/media?parent=981"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/categories?post=981"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/tags?post=981"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}