Bilge / keel delamination

[boatpoker]

Originally Posted by Terra Nova

I would not want either of you working on my boat.

Concrete?!!! Rocks?!!!

Build a proper mast step. Since you don't know how, hire a pro.

Agreed, these two seriously need some hands on guidance from a pro.

[dfelsent]

Originally Posted by roverhi

It was common practice in the days of wooden boats to fill voids around internal ballast with concrete. They were just trying to fill up space with something that was non compressable. Fibreglass builders poured in thickened polyester resin often with a thickening agent around loose ballast material in molded hollow keels.

Seems like whoever built the PO's boat either used concrete made with sand or some other fine grained agent. If they didn't put in enough cement in the mix it might break down over time. I'd bust out the crumbling mix and replace with polyester resin mixed with sand or some other non compressable material. Don't use epoxy as the the heat from the chemical reaction of resin and catalyst could start a fire in a conglomeration that thick.

Polyester curing is exothermic too. I’ve seen it char and smoke in a cup, let alone in a larger mass.
Thin layers, thin layers.

[robwilk37]

i chipped out the concrete and re-built the step (oversized) with laminated ipe massively glassed/epoxied over a large section of the hull. not an area to cut corners...

[psk125]

Vermiculite issues are well known to J/24 owners. It all has to come out. Replacing it with an epoxy slurry is a good idea, but as has been noted, has to be done in a way that won't melt things or start a fire. Read the Gougeon's (West Systems) book, which is available online for free. Thread is confusing. OP's profile says he owns a Southern Cross 31. Southern Cross 31 plans show a bulkhead, but no compression post? Replies talk about Catalinas. What is this boat?

[leveche420]

Here is how we finally addressed the issue:

https://doctorsailboat.com/2018-10-m...-and-moonrock/