Well, I've seen worse, like the hull in my signature - "16' Starcraft NEW Transom Skins" that looked like it got shot multiple
times with 00 buck from a shotgun.
Let me ask 1st, do you keep this on atrailer or is it moored or docked in the water? Also remove any bonding to the hull the PO did. Go back to the battery or to an Ancor brand 'Power Post' (acts like a remote ground, but is cabled to your battery negative post).
Here's what I would do ... but dependent on your answer above, I might add other suggestions.
Go enjoy the boat ...
- Remove anything and EVERYTHING off the tin panels where you now see any evidence of corrosion
- Ensure you remove any 'white' corrosion in the holes, then sand inside with agressive NEW 60 to 8- grit metal paper
- Wipe area well with white vinegar, then clean cloth with water on it - let dry
- Place duck tape on 'outside' of hull over hole
- Mix up West Systems G-Flex 650 (only $22 a kit) as it is a FLEXIBLE epoxy and fill the hole. You want a LARGE plug or blob of goop on the inside. You 'may' need to tip the hull sideways so as to keep the epoxy on the hole as it cures.Or keep wiping it back onto the reapir area. If you had cabosil fibers on hand, you couldthicken it somewhat or wait a tad until it begins to 'kick'. You can mix it reliably in tiny amounts (2 to 1 mix). I myself would not use a hard epoxy like JB Weld here ...
- When cured, remove tape (naptha or gas is your friend here, to remove any adhesive) and see how flush it is. If needed, skim coat a coat from the outside, but tape off surrounding area well, to within 1/4" or so of repair/hole
- Once satisfied, sand outside flush, multiple grits, and paint. Any bare tin should also be prepped with white vinegar (it etches aluminum), then rinsed and prime with aluminum primer when dry, multiple light/thin coats better than one globby thick one ...
- Paint as needed, I recommend Rust-Oleum regular enamal or their hard 'topside' paint version (darn hard, glossy finish!)
and just keep an eye on it.
If you have other questions, ask away and SHOW pictures as needed.
FWIW I've seen this on Starcafts of mid-90s to later vintage, (mine was a '96) believe it how the wood was or wasn't treated, if there's wood against those surfaces affected.