Backing Plates for C&C34 Stantions

[fesivo]

I just bought this boat and it has substsantial spider cracking aroung the stantion bases. By and large, this cracking developed due to poorly distributed stress; no backing plates.

The problem is that in installing the backing plates, I''ll be trying to secure stainless plates to the stantions on a surface that is not flat. I am wondering any of you have a reccomendation (success story) in using some sort of "durable" bedding compound to fill the gaps between the plate and the deck underside.

Thanks in advance. Frank

[RichH]

Make sure that the wooden (balsa or plywood) core beneath the stancheon base is not rotted. If there is rot, simple enlarge the bolt holes, dig out all the rot and inject with polyester mixed with colloidal silica. Try not to use epoxy as a fill, as the thickness of the epoxy might become severely exothermic during the cure, may expand (foam out) and crack the deck.
I use polysulfide as a caulk in ''chamfered'' bolt holes.
:-)

[munchimike]

AHOY!!....You can over plate and underplate, but remember that you''re augmenting an inital installation that was fualty; so you''ll have to go the extra mile to make sure you''re going to resolve ALL the issues and not just exacerbate an already poor state of affairs.Stanchion posts and mountings are notorious world wide for problems;...leaking being the most common, and of course the fibreglass issue,...well, you''re already working against a life expectancy that may have expired....cosequently, cover the bases any way you can. Take you upper and lower plates to a metal fabrication shop and have them apply the curve as supplied by you with a template;..then if you do use polysulphide, make CERTAIN that it''s TWO part rubber;....NOT that octopus snot that comes out of a tube..Meanwhile you may have to rebuild the entire area around each stanchion, in earnest....you may even go to carbon fibre if the areas are requiring compact re-inforcement.........Rev. Mike

[JMWyatt]

We''re replacing deck fittings as part of a general refit of our Pearson 365. In each case the core has been removed from the areas where the deck is penetrated and epoxy thickened with colloidal silica has been used as filler. In addition, we have prepared molded fiberglass/epoxy plates that are epoxied to the deck top and raise the base of the stanchion base 3/8-inch off the deck, reducing the potential for water pooling and penetration and ensuring a level deck surface beneath the fitting. The stanchions have stainless backing plates. To level the interior surface, thickened epoxy was added to the interior surface, then the fittings were put in place — coated with mold release — and removed after the epoxy kicked and had a while to cure. This leveled the interior surface and provided a solid base of contact for the backing plates. When we seat the fittings, we''ll use liberal amounts of sealant, allowing it to cure before snugging the fittings tight so that gaskets are formed.