Hull and deck repair

[Manu.El]

The deck laminates seem thinner in some places than I expected, I want to do some maintenance on this Tartan 34c both on the deck and down the hull, I know tartans from this era had solid reputations for robust hull construction, but I've never seen an official spec for laminate thickness, either above or below the waterline, also in the area of doing recore or reinforcement work, do I stick with the original thickness or add a few more layers while I'm in? I want to maintain the boat's balance and build philosophy, but if there are spots that could benefit from subtle reinforcement, near stanchions or winch bases I'd rather do it now than revisit it in a couple seasons
Anyone happen to have factory data or firsthand measurements from a project? I'd also be interested to know how much the deck differs in thickness across sections, as per the side decks vs. foredeck vs. coachroof and stuff like that

Appreciate all help

 

[therealbirdman]

Yeah, the deck thickness can definitely vary on these older Tartans, thicker where hardware sits, thinner elsewhere. If youre already in there doing recore or reinforcement, adding a few extra layers around stress points like stanchions or winches should do some good. Just don't go overboard, or you might mess with the boat's balance. Factory specs are hard to come by, but people usually find skins around 1/8"-3/16" and core about 1/2". Reinforcing key spots now will save you from tearing into it again later on

 

[equal_oven1251]

Yeah, the deck thickness can definitely vary on these older Tartans, thicker where hardware sits, thinner elsewhere. If youre already in there doing recore or reinforcement, adding a few extra layers around stress points like stanchions or winches should do some good. Just don't go overboard, or you might mess with the boat's balance. Factory specs are hard to come by, but people usually find skins around 1/8"-3/16" and core about 1/2". Reinforcing key spots now will save you from tearing into it again later on

When adding layers near stress points, do you taper the edges into the surrounding laminate or keep it uniform? And for core material, is it good to stick with balsa or do foam? Appreciate any guidance!

 

[TartanTitan]

The deck laminates seem thinner in some places than I expected, I want to do some maintenance on this Tartan 34c both on the deck and down the hull, I know tartans from this era had solid reputations for robust hull construction, but I've never seen an official spec for laminate thickness, either above or below the waterline, also in the area of doing recore or reinforcement work, do I stick with the original thickness or add a few more layers while I'm in? I want to maintain the boat's balance and build philosophy, but if there are spots that could benefit from subtle reinforcement, near stanchions or winch bases I'd rather do it now than revisit it in a couple seasons
Anyone happen to have factory data or firsthand measurements from a project? I'd also be interested to know how much the deck differs in thickness across sections, as per the side decks vs. foredeck vs. coachroof and stuff like that

Appreciate all help

That sounds like you've got a great project on your hands, and you're right about the hulls to be incredibly solid!
Unfortunately, you're not likely to find official laminate specs as builders back then just didn't publish that kind of data like they do today.
If you're drilling holes for hardware, use a depth stop on the drill bit and you can measure the laminate thickness easily.
In my experience, the hulls on Tartans of that vintage are incredibly robust, and there's no need to add thickness unless you've found a problem area.
The decks however are cored with balsa, so I'd focus my attention there.
If you're replacing core or mounting new hardware, it's not a bad idea to add a couple of layers of biaxial cloth.
That can add plenty of strength without affecting the boat's balance.