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Perhaps I went too far here but I was concerned about damage from the water and ice left in the bilge when I acquired the boat. The fiberglass skin wasn’t in great shape so I’ve cut it off to get a good look on the ballast. From reading the A30 mailing list seems the ballast is bedded in cement and or vermiculite. Definitely see clay substance filling the cavity fwd and aft of the pig and around the top and sides of the ballast is more of a sandy substance that could be the vermiculite. Hard to tell as there are lots of iron flakes mixed in.
I’ve been hitting the top of the pig with a coarse wire brush on an angle grinder which only slightly cleans the rust but does remove loose iron and bedding off nicely.
I’m wondering wether or not I should continue digging out the somewhat damp bedding around the sides to replace with something else like foam and if there’s anything extra I should do to seal the pig before FG to stop the rusting.
From reading horror stories I was concerned about the potential of a rusty ballast to expand and burst the keel but it seems like a solid pig expands much less than loose iron. Hard to tell if there’s damage from expansion from rust or ice on the outside. There are some vertical cracks on the exterior of the hull through an old barrier coat. Assuming that’s just crazing. Thinking about adding some glass over the hull seam on the outside to be safe.
You could drill a few 1/4" holes in the lower ballast area outside to see if any water is still inside and let it drain out. If you have humid conditions then you can dry the inside top of the ballast with heat or dehumidifier and then glass it closed. If there is any sign of a crack at the exterior hull joint then adding a layer of glass is good but not likely to be needed. Water ingress areas are likely from the bilge. I don't recall if there is any possible water path between the rudder shoe bolt holes and ballast cavity but probably not.
I'm thinking about fairing the top of the pig with thickened epoxy and filling in the large cavities with scrap fiberglass board. As for the sides where I've lost some of the filler bedding, I take it anything I can stuff down there such as sand is good?
This is will be my first glass layup and will serve as the bottom for an integral watertank under the sole in the salon. Im wondering if I should have my layup cover the entire surface area underneath the sole so there is one continuous watertight skin?
Is 1708 a good general purpose cloth for all structural work, tabbing, and patching?
1708 is good for this job. Sometimes you might want lighter stuff that goes around corners easier so you can also get some 4 and 6" tape rolls of something like 9 oz and maybe some 6 oz. Since it's a tank, yes you might as well run the glass up to the thank top. I'd probably use a polyester auto body filler rather than loose sand to fill the voids.
