Skip We owned a J Boat (J/27) for 7 years and before that a Hinterhoeller built Niagara 26 (call it a C&C as build is the same. All C&Cs of the era and all Niagaras of the era and every J boat built have wet balsa cored decks (the newer J Boats use foam of some sort). We replaced core on the Niagara in cockpit sole and large sections around chainplates and on the J/27 much more extensively. On the J/27 we documented under the Projects link on my website. It was all done from above. http://users.eastlink.ca/~mhoyt is the link to my site but there may be problems with some of the links so check back later
Basically it is an easy job when tackled from above. 1. Cut the outline of the area you wish to remove and decide then if you are keeping topskin or not. 2. If keeping top skin use wood chisels and wedges to remove. Is not easy but may be a good idea on contoured coach roof. A friend did this approach on coachroof of his J/27 3. If not keeping top skin then cut hash marks across the entire section to be removed down thru top layer of glass, then thru balsa and being careful not to cut the bottom layer of glass 4. Use wood chisel and hammer to remove all of the rotted and wet core. 5. Bevel or taper the surrounding top skin to give something for new cloth to attach to 6. After clean up of all residues etc (acetone is good for this) cut out three layers of glass cloth (6 oz is what I use) and the section of new core. 7. Place all three layers of loth in place and then thoroughly wet with resin once in place. You can use a paint brush or an epoxy stick or a spatula – whatever you like. Ensure there is excess resin covering the wetted cloth and then put the new core section in place. Weight the new core section with heavy objects ( a cinder block will do) but be sure you have a release cloth of some sort (plastic food wrap works) over the core before placing weights 8. Once cured (or nearly cured and still tacky) remove weights and food wrap and use thickened resin to fill in any voids surrounding the new core. Wait for a cure at this point 9. Grind off any excess cured resin and any bubbles and then cut out and apply three more layers of glass cloth. Overlap the area successively with each. 10. Once this is cured you grind sand off excesses and then apply more layers of cloth to build up followed by fairing coats of thickened resin once nearly level. Check level with a straight edge and sand with Random Orbital Sander (I use 80 grit) until smooth. 11. Its an old boat – feel free to paint the deck. If you are lucky and careful you can confine your repairs to thenon skid sections of the deck and the repairs ae masked by this. Tape off areas and use Kiwi Grip or Interdeck or similar for the paint. Once again I apologise that my web site is down as this is all documented with photos. I will fight with my cable provider to get this resolved. You can also attempt to do coachroof from underside. Get a West System Vacuum bagging kit to do this. A lot more information is available on West System site. Also on Sailing Anarchy there is a fixit forum sponsored by West System where you can ask questions and a lot also on the Sailnet Gear and Maintenance forum. You can decide to use either polyester resin (fiberglass) or epoxy resin. Epoxy adheres better but has much longer cure times and is far more expensive. Most boat repair shops use Polyester and you can even use a hybrid – polyester for the bulk of the work and then epoxy for the surface work and fairing layers. Remember that epoxy can go over polyester but that polyester does not go over epoxy You are lucky that you have no head liner. They may look nice but they are awful when working on your boat. You might also be able to hire a surveyor to map out the moisture in your deck. I had this done on the J/27 for a mere $40 and it gave me a schedule of repairs for the next several years. Best of luck. This is not very difficult work but is time consuming and weather dependent. A lot of people on this list have done this sort of work so keep asking questions. Mike Persistence 1987 Frers 33 Formerly Nut Case 1987 J27 #150 Formerly Full tilt 2 1979 Niagara 26 #002 Formerly P23 “Monkey Bear” Formerly Blue Horizon No. 1 (family boat) 1981 C&C 36 bought new From: CnC-List [mailto:[email protected]] On Behalf Of Joel Aronson via CnC-List Sent: Thursday, January 15, 2015 11:28 AM To: Robert Mazza; [email protected] Subject: Re: Stus-List balsa core Skip, If it is the core, I think it is usually done from above, preferably cutting along the edge of the non-skid and lifting out the glass. Others who have actually done it will correct me if I am wrong. I hope Rob is right that it is not the core! Joel On Thu, Jan 15, 2015 at 10:22 AM, Robert Mazza via CnC-List <[email protected]<mailto:[email protected]>> wrote: Skip, A few of observations: 1. It is unlikely that the brown film under your deck is core related. In my own C&C Corvette that film was emanating from the micro-balloon based fairing compound that was used to fair the underside of the deck, since, like your boat, the Corvette does not have a head liner. It was a dusty and dirty job to grind all that old fairing compound off and refair the underside of the deck with West Epoxy fairing compound, but since then it has been trouble free. 2. There is an excellent two part article on deck core repair and replacement in the last two issues of Good Old Boat magazine. Well worth reading, as is the whole magazine. I can say that because I'm a Contributing Editor, although I subscribed to the magazine well before that. 3. Hire a good surveyor (preferably SAMS or NAMS accredited) to tap and run a moisture meter over the deck to really determine the extent of the problem. 4. If core needs to be replaced, it should be replaced with new core, not solid glass, New balsa can be used, as long as all openings and fasteners are isolated from the core and all the kerfs in the core are filled with resin. That applies to foam cores as well. If foam it should be a minimum of 5 Lb. density. Rob On Thu, Jan 15, 2015 at 9:25 AM, Burt Stratton via CnC-List <[email protected]<mailto:[email protected]>> wrote: I have resigned myself to the fact that I need to address my decks and cockpit sole. The PO installed wood strips fore to aft on the cockpit sole ostensibly to provide some lateral traction. They were not properly bedded and as you might imagine, the wood strips did not last long. There are open screw holes and if I step next to them water comes out. That is an obvious problem. The reason I am concerned about my decks, particularly my cabin roof is the fact that a brown wet film will form over time on the inside of the cabin roof. My roof has no headliner. The paint was peeling badly when I bought the boat and I have stripped it off. If I clean the fiberglass and wait a few days the film gradually appears. My assumption is that there may be a wet core in the roof. I will get a surveyor to take readings with his moisture tool to confirm but assuming that is the case, I would appreciate any insight by listers who have tackled this problem. I am not an experienced fiberglass guy. I don’t particularly like working with fiberglass but I am pretty handy otherwise and would be willing to attempt this work in order to save a few hard earned bucks. Here are a couple specific questions: 1. What would the balsa typically be replaced with? An appropriate thickness of mat? 2. Should I attempt to save the fiberglass skin I remove to be re-used or just use new fabric to glass over the repair? 3. Assuming I work from the inside, how do I defy gravity to keep the new mat or fabric from falling down until it cures? Does the resin have enough mastic properties to keep it up? It is starting to look like the coming season may be lost for me. I have a lot to do and can’t do most of it until the temps increase. I do want to rehabilitate this boat and do it right. I think it will be worth it whether I keep the boat or sell her when I’m done. The boat is covered so I am hoping it will dry out a bit before I start. Thanks as always Skip 1974 CNC 33 3/4tonner On the hard in Walpole, MA _______________________________________________ This List is provided by the C&C Photo Album. Please donate to the C&C Photo Album to keep this list free for all subscribers. Email address: [email protected]<mailto:[email protected]> To change your list preferences, including unsubscribing -- go bottom of page at: http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com _______________________________________________ This List is provided by the C&C Photo Album. Please donate to the C&C Photo Album to keep this list free for all subscribers. Email address: [email protected]<mailto:[email protected]> To change your list preferences, including unsubscribing -- go bottom of page at: http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com -- Joel 301 541 8551
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