Patrick,
I concur with your degree of failure chart with the added "bad" comment of balsa that has rotted to black goo that smells of swamp and acidic polyester. I do have pictures but they are not posted online nor organized well. That organizational project will be waiting until Calypso is sailing again. PM me a email address and I will send a few next week (I'm currently out on the WA coast with the Mrs. and our dog for some R&R). If the failed core around the deck fills was shallow enough you could dig it out to firm balsa and refill with epoxy of other repair materials I would call that good to go unless it was in a highly stressed area. In several areas I dug out failed balsa back to firm core that was stained darker than new balsa. Once dried it tested well for structural integrity. The use of light hammer taps is my favorite way to confirm the extent of damage. I did find some filler used by Bruckmann's that was orange to brown in color. I refer to this low tech polyester based filler as "bog". Much of the bog on Calypso that has seen stress or water intrusion has fractured. If your deck fills are close to where the deck balsa ends and the glass tapers back to solid (for the hull to deck joint) the C&C factory may have added a filler. If the boat is not headed into extreme conditions, hard racing, or way offshore a little wet of mildly damaged balsa in low stress areas should not interfere with a sailing season. Light repairs and preventing further damage, especially re-bedding leaking hardware, in my opinion, is a better investment of limited repair time and resources. Martin Calypso 1971 C&C 43 Seattle ________________________________ From: CnC-List [cnc-list-boun...@cnc-list.com] on behalf of Patrick Davin via CnC-List [cnc-list@cnc-list.com] Sent: Monday, September 28, 2015 3:39 PM To: cnc-list@cnc-list.com Cc: Patrick Davin Subject: Re: Stus-List Balsa core damage Since we're on the topic of balsa core decay, I had a question about this - having just finished resealing all the deck fill ports (diesel, waste, 3 waters) on my boat. All had some softness in the balsa, two had obvious water ingress (in the past) evident by black staining, minor rust on fasteners (bolts/screws), etc. Question is how do you judge the *degree* of coring decay? Mild = ? (still wood colored, but squishy/soft?) Moderate = ? (dark staining and squishy/soft?) Bad = same as above but covering more than a 1 to 2 inch section? Severe = ? Purchase survey 7 months ago found no wet core issues via sounding, but did cite leaking fill ports so the need to rebed was known. Oddly one fill port (diesel) had what appeared to be dark brownish foam coring instead of wood, on only one side of the port (outboard, towards the toe rail). Maybe a prior owner injected it? Given I think what I found would fall under "mild to moderate", and percussive sounding found no issues further from the fills, I think the core decay is limited to just the immediate vicinity of the ports (water entry was probably through the fastener holes), and since the wood didn't feel presently wet or saturated, it was either a past leak or it's a very slow leak. I rebedded with butyl tape. Martin do you happen to have any pictures of your core? I assume you had some that would be good examples of more severe core decay? -Patrick S/V Violet Hour 1984 LF 38, Seattle, WA ---------- Forwarded message ---------- From: Martin DeYoung <mdeyo...@deyoungmfg.com<mailto:mdeyo...@deyoungmfg.com>> To: "cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com>" <cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com>> Cc: Date: Mon, 28 Sep 2015 20:30:21 +0000 Subject: Re: Stus-List Balsa core thickness ... When you start your project, evaluate how wet and the overall condition of the balsa before fully charting your course. If the balsa is damp (<30% moisture per the Baltek web site) and still looks tan and smells like balsa with a polyester undertone it may be OK to make small repairs around the deck penetrations. If you are able to go this route, be aware it is difficult and slow to dry out large areas of balsa using only the fastener holes. Let me know if you are interested in more balsa repair techniques / info learned from making extensive repairs to Calypso's deck. Martin Calypso 1971 C&C 43 Seattle
_______________________________________________ Email address: CnC-List@cnc-list.com 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
