Sea Hood Core Deterioration

Jun 21, 2004
2,907
Beneteau 343 Slidell, LA
Recently noticed that the seahood panel flexed & felt spongy when foot pressure applied. I usually don't walk on it; however, sometimes unavoidable. The panel is approximately 32"x40", covers the forward most position of the acrylic companionway slider when the slider is opened, and is a non structural panel attached to the deck with screws. I removed the seahood and drilled 2 four inch inspection holes into the underside surface of the cored panel; just as I expected, the balsa core was damp and had deteriorated. Really a mystery as no fractures or cracks were noted. The cored area on the under surface of the panel is approximately 24"x24", the balsa core is 3/8"--1/2" thick with a 1/4" laminate overly. I plan to cut & remove the laminated overlay and remove the deteriorated core, sand the inner surface to bare glass, vacuum, & scrub the exposed surface with acetone. I will use a new core material; thinking about corecell, divinycell, or coosa & epoxy resin + biaxial cloth overlay. Any suggestions for the core would be appreciated.
The photos show the top surface of the panel and the bottom surface with the two inspection holes and cored area.thumbnail.jpgthumbnail (1).jpg
 
Jan 11, 2014
12,975
Sabre 362 113 Fair Haven, NY
Sounds like a good plan.

You might consider making it solid fiberglass around the cowl vent. or any other penetrations. That will prevent any water finding the core from the mounting screws.
 
  • Helpful
Likes: BigEasy
Mar 26, 2011
3,720
Corsair F-24 MK I Deale, MD
The cover is curved; you do NOT want to use Coosa since it will be impossible to get it to conform without cutting it into very small pieces.

Any of the foams will work, but don't discount balsa either. It lasted a good long while, and I'm guessing you will find the leaks around the screws. You might use small (1-2 inches) pads of Coosa where the screws are. Scored balsa is easier to work with than foam. Another common error is that the glass on the underside was not fully wetted out in some area, making it porous. That happened to me.


More Rudder and Anchor Locker Lid Progress
 
  • Like
Likes: BigEasy
Jun 21, 2004
2,907
Beneteau 343 Slidell, LA
The cover is curved; you do NOT want to use Coosa since it will be impossible
Any of the foams will work, but don't discount balsa either. It lasted a good long while,
Pretty much the same that I am dealing with. Great write up on your repair with balsa. May reconsider balsa; it did last 17 years; perhaps if it was wetted out & laminated better, it may have lasted forever. Definitely the least expensive option. Going to remove the skin tomorrow & clean out the balsa before deciding on replacement core. Thanks for the insight.