Petar, were it me, I'd purchase some 1/2" fiberglass from McMaster-Carr and run a strip directly underneath the jib track and use balsa for the remainder. Should help with compression/water intrusion issues. Just my random thoughts...
Dave 1982 C&C 37 - Ronin Sent from my iPhone > On Feb 8, 2016, at 09:40, Petar Horvatic via CnC-List <[email protected]> > wrote: > > So I did some digging over the weekend and I can say few things regarding > deck and core along the genoa tracks for C&C38 mk2 from 1976. > Top laminate is 3/16” thick. Balsa is ½”. > In my case, wet areas are pretty extensive. Tapping and sounding the top got > me to mark out a big rectangular area. It extends from about 2” inboard of > the genoa track and its about 12” wide. It runs the length of the track. > There is a 4” wide section of marine ply (also 1/2” thick) under the track > itself. I wonder if I do the same or just keep balsa. > I posted some horrifying photos on cruisers forum. Warning, pics are pretty > disturbing. > http://www.cruisersforum.com/forums/showthread.php?p=2039627#post2039627 > Haven’t done the bevel yet, and still have about an hour to get all the rot > out. > As I said on CF, I’ll do epoxy repairs and use the double bias stitch mat and > toss out the top laminate. I’ve had enough of polyester. Its porous > nowhere near as strong, and if you go to trouble of doing this much work, > might as well not skimp out on material. The big question is how to > transition to gelcoat again? > The cutout is the length of the track so I am not worried about genoa cars > getting stuck on the track due to deck transitions. > > Petar Horvatic > Sundowner > 76 C&C 38MkII > On the hard at Stanley’s in Barrington > > > > From: CnC-List [mailto:[email protected]] On Behalf Of Hoyt, Mike > via CnC-List > Sent: Wednesday, February 03, 2016 1:23 PM > To: [email protected] > Cc: Hoyt, Mike > Subject: Re: Stus-List repairing large wet deck core areas > > Petar > > This link shows a recoring project on our former boat > http://users.eastlink.ca/~mhoyt/Projects/recore/recore.htm > > Initially we had 4 stanchions that had cracked deck (not just gelcoat) at the > stanchion bases. The first year I recored these four areas only. The link > above details that job. The following year I had a surveyor check out the > entire deck and hull for moisture. We noted the wet areas (all on the decks) > and replaced the core in all remaining wet areas except the cockpit seats > (done another year). This project involved replacing the core under the > genoa tracks and also under the primary winches among the 14 areas of > problem. > > When I replace core material I never save the top skin. However I do know a > lot of people do and that is your option. Most of the wet areas on a deck > are in non skid areas so it is very easy to rebuild your own top skin and I > find that process a whole lot simpler. This is my preference but not > necessarily better nor worse than keeping the top skin and reusing. The two > benefits of not reusing top skin are 1. It is more work to remove the top > skin than to discard it and 2. You may get air voids under the replaced top > skin if not done well. The benefits of retaining the top skin are that you > have the contours of the deck area saved. This is nice on a coach roof for > example > > When I start removing the core I normally drill some pilot holes to determine > how far the wetness and the rot extends. Typically the rot is localized but > the moisture travels quite far. I cut out the area that I know is wet and > then if I am still in wet core I continue removing until I get to dry core. > Note that wet core is not soft. Rotten core is soft. Wet balsa can actually > still adhere quite well to the bottom and top skin and be strong. However > why would you leave it? It is not much more work to replace core in a 1 x 4 > ft section of deck than it is a 6” by 2 ft section. > > For an idea of the labour involved compare to a bottom job. Nut Case our J27 > took 50 hours to strip the bottom to gel coat (by hand), apply barrier coat > and then antifoul. By comparison was only 30 hours to replace four sections > of core material that same year. > > Note that I have done this job using polyester resins (large areas and cost) > as well as epoxy. > > If you have any questions do not hesitate to ask. > > Mike > > From: CnC-List [mailto:[email protected]] On Behalf Of Petar > Horvatic via CnC-List > Sent: Wednesday, February 03, 2016 12:45 PM > To: [email protected] > Cc: Petar Horvatic > Subject: Stus-List repairing large wet deck core areas > > Hi all, > I am getting ready to tackle the wet deck along the port genoa track and > before I start cutting, I have few questions for the group. > > Gelcoat cracks and delamination is appearing almost the length of the track > on my 38 Mk2. I realize that not all spider cracks are due to wet core, but > there is some strong indication that at least ¾ section of geona track area > is rotten. Namely, top deck is noticeably indented along the track from > compression of backing plate and track screws. I also remember that water > was coming out of the tracks in areas where track was under load. > Especially area in the aft section. I pulled the track off last night and > there is strong oxidation along the aluminum backing plate where ss washers > and nuts were. > > Any idea on how to determine how far athwartship to go when cutting out the > top laminate? I guess tap with a mallet? Do people mostly save the top > laminate or decide to lay new one from scratch? I am also thinking that it > would be better to cut the area so entire genoa track is included so that I > don’t have to deal with potential of uneven surface between repair area and > untouched area where genoa track lies. I can foresee potential issues with > the car not riding smoothly in area of that transition. > > Thanks > > Petar Horvatic > Sundowner > 76 C&C 38MkII > On the hard at Stanley’s in Barrington > > > _______________________________________________ > > Email address: > [email protected] > To change your list preferences, including unsubscribing -- go to the bottom > of page at: > http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com >
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