Eureka repairs and finish problems

I've been a bad boy and pranged my Eureka.
On the Yarra near Ivanhoe there's a small set of rapids that I'd never had the gumption to get up past before. This weekend I got a rush of blood to the head and paddled upstream through it at full pelt, until the inevitable crunch happened.

Here's Problem A:
There's a small puncture hole on the outside of the bottom panel, about 25mm from the port bilge/bottom chine, and almost directly in line with the aft edge of the ply butt-block panel inside.
The hole is about 25mm long and 5mm wide (running longitudinally), when viewed from outside.
It's delaminated the ply locally, and a piece about 35x35mm by about 1.5-2.5 plies deep has popped up inside the boat.
The boat is fully sheathed with fibreglass. I can't remember the weight of fabric, and just threw out the unused fabric offcuts 6 months ago (@%$*?! typical...).

Here's what I plan to do:
Cut out a square of ply bilge board from the inside, minimum 45x45mm, depending on the extent of delamination & water ingress I find.
Sand down a scarf fore and aft on the outside of the hole (one of the sides will meet the chine) and sand away the fibreglass sheathing about 50mm or so all around the perimeter of the hole.
Make a matching scarfed 6mm Gaboon ply plug. Scarfs will be about 35mm long or roughly 1:6.
Epoxy to the outside with thickened pox, sand and tidy up inside & out. (Hold in place while curing with a brick wrapped in gladwrap, or packing tape round the boat, or something.)
Cut a small sheet of glass fabric and lay over the plug and sanded-away area. Epoxy up.
Sand the edges down to marry to the level of the adjacent sheathing.
Epoxy and finish all round.

Problem A questions so far:
Is this an appropriate repair method?
Provided the intenal damage / water ingress doesn't extend too far, does the size of plug sound reasonable?
What weight of glass fabric would people reccommend (I've totally forgotten what I used originally, but have assumed about 6oz).
This all requries minuscule quantities of ply, glass fabric etc. What's the best way to purchase repair materials (I'm in Melbourne) without buying full sheets of ($$) stuff? Do the ply and glass guys sell offcuts or part-sheets?

Here's Problem B:
I used clear Aquacote on my Eureka, and it's been stored under a Sunbrella fitted cover for about 2-3 years.
The Aquacote is starting to lift & peel quite thickly off the gunwales (hard, thick pieces), and in very fine layers (small, soft rubbings) off the inside ply panels (esp. the bottom panels).
I thought I did the right thing applying it, and followed the instructions on the pack...

Problem B questions so far
What are my options if I've stuffed up somewhere? Sanding back the entire boat to epoxy substrate? (That will be a bummer around the inwale blocks).
If there's some sort of substrate contamination (additives in sandpaper? Masking tape or tarp construction cover? Air pollution? Sticky fingers? Epoxy was BoatCote, so that should be compatible)
Can I sand back the troublesome bits and coat over with something more traditional, like spar varnish?
Gunwales do get the occasional ding while launching and retrieving - does this sound like water ingress? I do try to touch-up each time.

I guess I should give BoatCraft/AquaCote a call and ask their advice, but I'd appreciate any thoughts any of you have...

Cheers all,
Jack

G'day Jack
You'll probably want to make the patch bigger to allow for 1/6 or greater slope for the scarf. This will enable you to cut away any unseen damage between the plies. Another option instead of the scarf slope is to use a router set to exactly half the thickness of the ply and create a stepped joint. I used this option with my GIS when I stuffed up the centrecase placement. For a small area like you've got maybe some 50-100mm wide fiberglass tape to patch it up on the outside, you can buy it in small amounts for cheap.

Regarding the aquacote, I'm using it at the moment so I can't pass on more than is in the tips and directions for it on the boatcraft website. They are pretty big on making sure you don't contaminate the surface with any oils (including the ones on your skin).

Cheers Dan

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Hi Dan,

Yes, the patch will be about 45mm long in the flat, full thickness part, with the scarf extending at least 35mm (just shy of 1:6) each side, so at least 115mm long overall - a pretty credible battle scar.
I like the stepped router idea (the edges of the patch would probably be a whole lot tidier that way) , but sadly don't have the necessary kit.

Bingo on the tape - that's a good idea and will save a whole lot of wasted fabric.

Thanks,
Jack