Topside delamination - Divinycell core

[Yngmar]

The surveyor found a large area (about 40 cm diameter) of delamination at the topsides about where the holding tank is on the Bavaria 40 Ocean I've made an offer on. Surveyor says it can be repaired, either from outside or inside by removing the holding tank. Obviously will have to either get seller to sort (but there are concerns about it being done on the cheap then) or renegotiate price.

It looks like the delamination was caused by the hull being compressed or having flexed (it's right at the max. beam, but nowhere near the shrouds or anything else). There are signs of it having been repaired before (drill and fill), but that clearly didn't last, so it's time to do it properly now, by exposing the core, replacing it (if crushed, which seems the likely cause for the delamination) and then rebuilding the layers. I do remember reading that the core on ~2000 Bavarias is a Divinycell foam sandwich, but that's all I know.

So has anyone done this before? How much did it cost? Perhaps any recommendations on the south coast?

And to satisfy my own curiosity, I'd like to know what's the exact type of Divinycell foam used (there's many with different properties) and which glue to use to fit the replacement core section.

So many questions

[IslandAlchemy]

Divinycell is just a brand.  It's basically a closed-cell foam.

To fix properly, you'll have to strip out inside to get at the inner skin, cut the inner skin out with an oscilating saw, hack the old foam out, glue in a new piece of foam (using epoxy & fillers), then replace the inner skin and glass it bak in-place, and then re-build the interior.

I doubt you'd get much change out of about £3k.

However, were it me, I'd negotiate the price down (start at £5k off), and then ignore it (it's not causing any harm after all).