brigait1 Posted March 30, 2011 Posted March 30, 2011 I'm scheduled to flip the hull of my CS20 this weekend. So far the cockpit has the bulkheads, centerboard trunk, and seats fully installed. So my question is this; when we lift the boat off the cradle is it strong enough to set down in the yard before flipping? Or should we plan to lift and flip all in one shot? Right now the boat sits in a cradle at the forward and aft interior bulkhead positions with a support block under the middle near the aft end of the centerboard trunk. I will need to remove the hull-supports from the cradle and replace them with straight supports for the inwales to rest on. You can kinda see it in the attached pic. I'm sure my flipping crew would rather not stand around holding the boat while I do this. The hull is made of hydrotek which is a bit heavier than okoume, but not drastically so. Any thoughts or suggestions are appreciated. More project pics here: http://goodfootsailing.blogspot.com/ Quote
Joe Anderson Posted March 30, 2011 Posted March 30, 2011 This is my EC 22 I think in a similar state of build. No exterior reinforcement on the hull and not much support for the gunwale. I had no concerns setting the boat down. I think the greatest stress was when tipping the boat up on edge. I do not see seat tops in your photo which I think add a lot of strength if the boat is on edge. Quote
brigait1 Posted March 30, 2011 Author Posted March 30, 2011 Thanks Joe. Yeah, the photos are not the most recent. The seat tops are in now. I had the same thought on the vulnerability of the sides at the inwale when flipping. I may add some athwartship bracing at deck level to help shore things up a bit. How many people did it take for your flip? BTW, She's looking great. I hope I get to sail with you some day Pete B Quote
John Burritt Posted March 30, 2011 Posted March 30, 2011 Notice that Joe has temporary cross pieces to minimize distortion at the gunwale. Probably a good idea. Oops. Guess you did notice. Quote
Joe Anderson Posted March 30, 2011 Posted March 30, 2011 I had three helpers. I did worry about stressing the inwales and they were well braced. I think Wes rolled his by keeping the transom on the ground. Touching one corner and then rolling across the transom. I think much less stress on the boat that way. Good luck it is an exciting moment. Quote
Ray Frechette Jr Posted March 30, 2011 Posted March 30, 2011 Hydrotek is very noticeably heavier than Okoume in a hull. I have flipped both hulls and was amazed how much heavier the Hydrotek was. Quote
PAR Posted March 30, 2011 Posted March 30, 2011 Hydrotek is 20% heavier the Okoume, so a 350 pound hull turns into a 420 pound hull. Quote
Tom Lathrop Posted March 31, 2011 Posted March 31, 2011 Some of my measurements of meranti have gone to 24% heavier than occume if that is what hydrotek is. Anyone else made a number of measurements? Supplier's weight claims are not too reliable. Quote
PAR Posted March 31, 2011 Posted March 31, 2011 Yep, I've noticed considerable difference in meranti weight over the years. Red meranti can vary a lot. In fact, it varies by sub species too as there are five common ones; Shorea contorta, Shorea leprosula, Shorea leptoclados and Shorea smithiana are the light reds and Shorea negrosensis is the dark red. What's worse is my data base shows at least 14 different sub species under the Dipterocarpaceae family, all could be and are been imported as meranti. If this isn't confusing, try a search for lauan or Philippine mahogany. I did a quick global search in my Wood Handbook PDF for Philippine mahogany and got 23 out of 40 of the real mahoganies and the Shoreas and their sub species, plus a few others. I didn't even try lauan, knowing what it would bring. Back to the Hydrocore/Hydrotek products, most of these are the red Shoreas. I've gotten some Lebbek (Albizia lebbeck) which should be avoided if it has much sap wood in it. It's fairly easy to identify with a dark brown heart wood and yellow sap. The heart wood is very strong, but the sap isn't. Every once and a while I see a sheet with this stuff in it. It's contrast is dramatic, the grain figured a bit, spits, checks, etc. I currently have about 18 sheets of meranti in stock and all appear to be one of the light red Shoreas. Now that you've brought it up Tom, I'll weigh each in the next day or so. It's been raining down here like a hurricane has rolled in, so I'll have time. I wouldn't be surprised with a 5% fluctuation above the "usual" weights. Okoume does too, but the color usually gives it way. Quote
brigait1 Posted March 31, 2011 Author Posted March 31, 2011 Yes, I did notice from the outset that the Hydrotek was heavier. It is also considerably stiffer. When unfolding the hull and placing the forward bulkhead, I had to recut it (the bulkhead) because the bottom seam wouldn't spring open as far a it does with okoume. Not a huge difference, but noticable. The upside of the additional weight is how tough this stuff is. A had a few small scraps of the stuff sitting in an old wheelbarrow through the winter. They got soaked, frozen solid and thawed multiple times and still look pretty much perfect. No delamination at all. So I guess I'm just gonna deal with the extra weight by trying no to carry too much stuff with me when sailing. Thanks for all the replies. I will post pictures of the roll-over party next week. Cheers, Pete Quote
PAR Posted April 1, 2011 Posted April 1, 2011 For Tom's benefit, after averaging I got 25.5 pounds for the 1/4" Meranti I have on hand. One sheet was notability heavier, possably one of the dark red Shoreas snuck into the batch. This works out to be 6% heavier then the manufacture said the material would actually weigh. Though I did have 3 sheets that were slightly lighter and 4 sheets that were dead on, the remaining 11 sheets all were heavier then the "standard". Quote
wkisting Posted April 2, 2011 Posted April 2, 2011 I had three helpers. I did worry about stressing the inwales and they were well braced. I think Wes rolled his by keeping the transom on the ground. Touching one corner and then rolling across the transom. I think much less stress on the boat that way. Yep, with ours I had five or six helpers, but three would've been enough. We carried it clear of the concrete onto the lawn, let the transom touch a piece of dropcloth layed out on the grass (to keep dirt off the wood) and rolled it over that way. Then carried it back over the concrete onto the cradle again. Worked great. Wes Quote
brigait1 Posted April 4, 2011 Author Posted April 4, 2011 Well I ended up with plenty of help. Seven guys including myself. So it went off without a hitch. Here's a few pics. Quote
brigait1 Posted April 4, 2011 Author Posted April 4, 2011 There is a more complete description of the process at the blog. http://goodfootsailing.blogspot.com/ Thanks for all the input. I'll post more pics as things progress. Pete Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.