Was: Deck Core Thickness? NOW: Deck Replacement

[BenTen]

I've tried searching but couldn't come up with an answer: What is the Balsa Core thickness that was used on the decks of an 80's Carver Mariner (3697)?

I emailed Carver but they are yet to answer me so I'm hoping one of you might know either from experience or by coming across someone else who needs to make a soft deck repair. I want to order all components and have everything on hand prior to cutting the deck open which includes the correct core material.

Thanks!
Ben in SC

[Cooler]

Ben - hopefully Carver will answer soon. Did you include your hull # in the email? That would allow them to inspect your specific vessel construction log if they have it. A number of logs were destroyed in a fire they had in late 90's. The other thing you could do is cut a small sample of the area you are ultimately going to repair if possible. Drill out a 2 inch sample circle and inspect the layers that way. Pick a spot that will not leak any water stored in the coring. If it is soft you should avoid any stress in that area anyway. If the balsa got wet, it may be compressed and literally falling apart. Depending on where this repair is, there may not be any balsa. They also used coremat depending on the location and model. They recently shifted some staff around and may not have as many people responding to emails. er

[Cooler]

Finally, another thing to do is remove one of the fittings on the deck, like the waste fitting, and then reseal it when you reinstall. That should give you enough visibility to inspect layers. Good luck. Next time I see one of the old Carver guys, I'll ask if he remembers. er

[BenTen]

Cooler, that was a great idea! I happened to be at the marina when you replied so I popped the top on the hawse hole and measured the core there and it is 1". This is much thicker than I expected so I still might drill a test hole in the side deck to see if it might be thinner than the fore deck.

I'm was also considering going back with marine ply instead of balsa but at 1" that will be a considerable difference in weight.


Thanks,
Ben in SC

[Cooler]

Cool beans. Good idea on an additional test. Do that one right at the area you are having issues with. Is it soft or are you dealing with stress cracks? Carver did beef up the construction materials for all boats 36 & above, so it makes sense. There are a lot of 80's models still cruising, so they obviously did something right. I see more older Carver than any other brand. Maybe because of the area, and granted a lot of Carver owners used them as cottages with low cruise hours, but I see way more than any other brand. Remember to reseal anything you remove, even the screw holes. Publish your findings. There are others who would like to know, even if it's just for peace of mind. er

[Cooler]

Update. I was at my boat yesterday. There was a technician working on the boat next to me. He was removing a hatch to repair rotted balsa. He measured the core at 1" also. That was on an early 90's Sea Ray, 36 ft. He said 1" core was an industry norm for the size boat. He dug out the rotted balsa, is letting it dry out for a while, then he said he is going to use foam to replace the rotted balsa. Hope this helps. er

[BenTen]

Cooler, thanks. I just drilled a 2" hole to test two things.

1. To confirm the core thickness, and it was indeed 1".
2. To check the stress cracks in the gel coat to see it they were the cause of water intrusion. They were not the source, it is/was instead improperly bedded stanchion mounts all along the starboard side.

I'm having a hard time locating 1" balsa so I'm also considering foam. Lots of topics to be read on this subject across the different forums. Either way I'll be tackling this repair on my own as I feel confident in my ability here.

[1992330aftcabin]

Ben, 1/2 balsa is available at Most hobby shops. You can double it to make your 1 inch. Make sure you epoxy it together and around the sides of the new and old balsa, that will give you a Olin core. Hope this helps. Mike.

[1992330aftcabin]

Solid core.

[BenTen]

1992, thanks for the backup plan. I was able to locate some 1" true core material at Defender so I'll likely just go that route.

For anyone interested here is what my test hole came out looking like. Very wet! I also pulled the adjacent stanchion and to my surprise the holes are all properly sealed from the core. Sooo my guess now is that the poorly installed Windlass and Cleat on the fore deck is probably the real culprit.

Is it possible for water to travel that far in the core, especially since the individual balsa blocks are supposed to be sealed from each other to isolate water leaks? I'm sure I'll learn more once I open things up.