Teak Portholes

[JamesG123]

By the way, you don't get any appreciable humidity cycles when you encapsulate wood in epoxy.

Until the thermal cycles within the wood and between the wood, the fasteners, the glass , and the surrounding structure makes it crack and split. Or when it gets chipped.

If you want to do it. Do it. Don't whine when you don't get results you were looking for.

 

[Blueknarr]

Until the thermal cycles within the wood and between the wood, the fasteners, the glass , and the surrounding structure makes it crack and split. Or when it gets chipped.
Or the hull flexes differently than the wood.

Your goal of exceeding Pearson's craftsmanship is easily achieved. I believe that their only boats that didn't start leaking at two years old; left the factory with leaky ports.

I am sure that you will do a proper leakfree installation. But, all ports will leak eventually. I suggest you rebead them every time they need a full clear coat redo.

One of the vessels I mentioned working on previously was a Pearson 35 with teak over plastic ports. They absolutely enhanced the beauty.

Good luck

 

[Asleep Helmsman]

OK guys, thanks for the input, and warnings.

If they (the porthole frames) end up being teak, I will resaw the wood I have and make the whole thing laminated with west system epoxy. On the back side I may add a couple of layers of glass. This should solve most of the concerns y'all expressed about different materials all moving in different directions.
I couldn't conceived of a worse way to do them then Pearson did. As Blueknarr pointed out: "left the factory with leaky ports", with their insane squeeze technique.

They squeezed Plexiglas between two machined aluminum frames. The idea of using epoxy-teak came from the fact that I have over a hundred board feet of teak, and I wanted to make the connection to the cabin a separate one from the connection to the Plexiglas. So the frame could be attached to the cabin with 4200/5200, and the Plexiglas could be attached to the frame with silicone, or what ever is being recommended.

So, it wasn't complete insanity that started this inquiry.

 

[Asleep Helmsman]

Update:
Many newer boats have frame-less portholes. This allows the frame to be strictly decorative. I have a mortising machine for using loose tenons, so the joinery problem is solved. The encapsulation with West 105/207 will solve the movement problem. I'm confident this will work . Picture coming.

 

[Asleep Helmsman]

Finally getting around to the port holes.
As stated earlier, the port holes which are less than a meter long, reducing the continuously overemphasized thermal expansion differences. Are going to be bolted to the side of the cabins with machine screws 2.5" on center.

Here's where I'm inviting some more criticism. Going to put a few spacers around the porthole to force it to be around 3/32 away from the side of the cabin.
1. Should spacers be rubber washers around some of the bolts or stainless steel. This is between the acrylic and the FRP sides
2. Caulking around the installed acrylic with Total Boat Marine Sealant. from both the inside and out side.
3. Taping around the outside of the Plexiglas with Gorilla Water Proof Tape cut down to 1.5".
4. Make the epoxy encapsulated teak porthole frames with loose tenons and screw them down from the inside. Sealed to the FRP with 3M 4000.



Seal Elastomeric Marine Sealant https://www.totalboat.com/product/seal/
https://www.amazon.com/Gorilla-4612502-Waterproof-Patch-Black/dp/B07HSKRYQW