J/80 Deck recore question

[Captain Jack Sparrow 85]

Planning for offseason projects. I have an old (1994) TPI J/80. Soft spot with delam in cockpit floor just ahead of the port side scupper, maybe 1' x 1' area. There are a couple areas on the deck aft of the chainplates that look like they may be having issues in the near future (they sound out solid still).

Does anyone know the balsa thickness used in the construction of the decks of these boats? I know the hull is 3/8". Is the deck and cockpit sole the same thickness?

In the event nobody knows, I'll just cut it open and measure, but I am hoping to have the new material here before I start opening up the deck. 

[charis 15]

When I removed some wet core around the chain plates it seemed like 3/8, but I didn't measure since I was just filling with thickened epoxy.

[Captain Jack Sparrow 85]

On 11/30/2021 at 3:57 PM, charis said:

When I removed some wet core around the chain plates it seemed like 3/8, but I didn't measure since I was just filling with thickened epoxy.

Thanks. I'll probably just have to measure. I'll be going through most of the deck to find any problem areas this spring, so I only have to (hopefully) deal with it once in the near future. 

[charis 15]

2 hours ago, Captain Jack Sparrow said:

Thanks. I'll probably just have to measure. I'll be going through most of the deck to find any problem areas this spring, so I only have to (hopefully) deal with it once in the near future. 

Post some pictures when you do.  We'll all be interested to see how it goes.  Are you going to remove and reskin from the inside?

[WCB 778]

I second the idea of 3/8". I have a deck repair that I need to do on my J22 and I just yanked a piece of balsa core out of the area to measure it and it is 3/8".

[longy 855]

Since you're repairing the area anyway, just drill up to the underside of the deck with a small hole saw. This will show you how thick the core is and how wet things are

[Captain Jack Sparrow 85]

22 hours ago, charis said:

Post some pictures when you do.  We'll all be interested to see how it goes.  Are you going to remove and reskin from the inside?

Will do. The location and nature of the damage makes going in from the top the better choice. The area is just forward of the transom, in the cockpit floor on the port side. Getting in underneath would require putting a hatch or cutting a large temporary access port in the rear bulkhead that is under the cockpit. The top skin (deck) has a fair amount of crazing and isn't perfectly flat anymore- probably from water freezing in there and then forcing the skin up. 

Being an older boat, over the next couple seasons I plan on repairing a few areas of deck (near the chain plates, jib tracks) and then repainting the deck. I'll probably go cut off the top skin in the next couple weeks and figure out what I need to order.