Greg - agreed with Russ (and Joe.) When I did mine I briefly went down the calculation rabbit hole, looking at the properties of materials etc and I realized there was no way for me to calculate the hypothetical combined load of keel bolt torque, mast/rig, and one bolt's worth of bashing a rock at 4kts. My brain elected to look at the original construction and make it stronger (compression posts, epoxy, carbon fibre....) and move on to other projects. I used glass and carbon fibre (recommended by the local composites purveyor) instead of AL as others have done, but, same idea. My dad (builder of many boats- now in NS) suggested concrete as fill and he was probably right.
Dave ---------- Forwarded message ---------- From: "Russ & Melody" <russ...@telus.net> To: cnc-list@cnc-list.com Cc: Bcc: Date: Tue, 27 Jun 2017 21:52:15 -0700 Subject: Re: Stus-List 33 mk2 Mast step loads Hi Dave, Watch those units. 4000 PSI on a 6" x 8" mast step plane is out of this world for a 33 foot boat. When I did the mast loading while designing the rig of my old 60' cruiser it was 100,000 lbs and he's telling you it's twice that?? I would go with Joe's suggestion of 1/2" aluminum plate and move on to other projects. Cheers, Russ *Sweet *35 mk-1 At 08:24 AM 27/06/2017, you wrote: Content-Language: en-CA Content-Type: multipart/alternative; boundary="_000_BY2PR02MB458E0206231C27457085F 24B1DC0BY2PR02MB458namprd_" Thanks everyone for the info. I spoke with Danny from Klacko spars yesterday and he's certain that he would have installed my original mast in '87. He figures even when falling into a wave with full sails the forces wouldn't exceed 4000 psi. Seems light to me but who am I to argue with him. I thought I notice Mr. Knowles at the club on the weekend so I'll definitely run it past him - thanks for mentioning that. I have the entire mast step "excavated" to the keel and am starting the rebuild. Can't wait for this one to be finished! Thanks! Greg 33 mk2 Halifax On Jun 27, 2017, at 10:52 AM, Della Barba, Joe via CnC-List < cnc-list@cnc-list.com> wrote: I used a total of ½†aluminum on mine when I rebuilt it. It looks about 20 times stronger than the original was too. Joe Coquina CC&C 35 MK I
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