The 3 Resins over Plywood

[Chotu]

Ok, I’ve been building long enough to know what holds up in the long run and what doesn’t.

Resins over plywood WITHOUT at least a small layer of glass do not hold up too well. They get easily nicked and if continuously exposed to water, they rot. Even epoxy.

I’ve found wood bits with epoxy and glass do stand up over the years.

My question is about alternative resins.

I need to build my sail control table very soon. This is a table inside the boat where all the control lines run to. It will have winches and line stoppers and all of that, as well as spots to put the bitter ends and excess length of lines.

I was going to do foam/glass but for speed, I’m considering Okoume and a resin with a tiny veil of glass for durability. It’s indoors on the bridge deck anyway.

Question:

Epoxy is great on wood. Polyester is so-so on wood. Where does vinylester stand?

[fourlyons]

Chotu, I apologize for responding but not answering your actual question. However, if the table is inside why bother with glass and resin, why not a good hard lpu paint? If it's for a little more toughness, why not use 2 sided mdo plywood (painters board), it comes with a phenolic resin/paper skin that is tough, smooth and is cheaper than okume?

[Chotu]

Originally Posted by fourlyons

Chotu, I apologize for responding but not answering your actual question. However, if the table is inside why bother with glass and resin, why not a good hard lpu paint? If it's for a little more toughness, why not use 2 sided mdo plywood (painters board), it comes with a phenolic resin/paper skin that is tough, smooth and is cheaper than okume?

Sure. As long as it’s extremely lightweight. That’s why I use Okoume for everything wood.

Painting over wood sounds fantastic to me though. Very fast. Easy. Way less toxic than all the other options.

I’m always doing everything to overkill levels on the boat. Perfection. That has been my enemy the whole way.

And you know what? My indoor Helm station is actually Okoume with LPU over it. No one could ever tell that it’s not part of the standard fiberglass laminate everywhere else.

So that was a good reminder.

It will be occasionally soaking wet running rigging passing over this table. What about the drill holes through the wood? Do I have to worry about that? If water droplets get down in them? Or am I doing overkill again worrying about that?

[rslifkin]

I'm thinking along the above lines as well. If it's inside, the level of waterproofing required is lower (although you'll still have wet lines coming in on top of the table). I'd be inclined to either build it out of good wood with good paint, or maybe bolt together a metal frame for most of the table so you only have to build a top for it (and can easily put storage under it if desired).


As long as the top of the table can handle some moisture from the lines and the thing is strong enough, pretty much anything will work.

[smj]

What about pre glassed foam or honeycomb? Less work but more $$$$’s, and even comes pre gelcoated!

[MicHughV]

I'm a fan of WEST System epoxy, first coat pretty much sinks into the wood. Second coat, with some added filler and color ought to the job...off course, there is the "epoxy" question for you, but if someone could build it for you....???

[s/v Jedi]

Coosa board. Any holes over drill, fill with solid (3M vinylester filler) then drill & flare. LPU paint it.

If the Coosa needs more glass then just use 1708 with polyester

[fourlyons]

Originally Posted by Chotu

Sure. As long as it’s extremely lightweight. That’s why I use Okoume for everything wood.

Painting over wood sounds fantastic to me though. Very fast. Easy. Way less toxic than all the other options.

I’m always doing everything to overkill levels on the boat. Perfection. That has been my enemy the whole way.

And you know what? My indoor Helm station is actually Okoume with LPU over it. No one could ever tell that it’s not part of the standard fiberglass laminate everywhere else.

So that was a good reminder.

It will be occasionally soaking wet running rigging passing over this table. What about the drill holes through the wood? Do I have to worry about that? If water droplets get down in them? Or am I doing overkill again worrying about that?

The mdo is usually doug fir or larch, roughly 40# per cubic foot, a little heavier than okume. However it is stronger and more rot resistant than okume.

[Bill O]

Originally Posted by s/v Jedi

Coosa board. Any holes over drill, fill with solid (3M vinylester filler) then drill & flare. LPU paint it.

If the Coosa needs more glass then just use 1708 with polyester

Agree w/Nick on using Coosa, especially if you are trying to cut weight. It's the same strength ("Blue Water") as ply at 1/3rd the weight. Also no water absorption or rot.

[fourlyons]

Having used a lot of Coosa, I agree it is a good suggestion. However, it really needs to be covered in a layer of glass, otherwise it dents and gouges easily.

[Bill O]

Don't disagree that it could dent, etc. Would use vinyl ester since it wets out the glass better than epoxy.

[Chotu]

Cost is a concern too. Of course no epoxy as that’s the most expensive of all as I need to have it put together for me.

Coosa is $374 a sheet?

[Bill O]

You have an exotic boat and you want to keep it light. Sometimes you have to pay a little more for premium parts.

It would be slightly less expensive if you use a 20lb density (vs. 26).

[GRIT]

I'd go with paint over okoume ply. It's as tough as you'll need, affordable, and made with water resistant glue. I might seal the holes with something, resorsinol? But I wouldn't overdrill and epoxy them. Wooden boats have been using marine ply for 60 years, and most used to just drill a hole and seal the fitting.

You're inside so it's never going to rot, even with a few damp lines on it.

Good luck, and please post pics of the finished table.

Cheers.
Paul.

[Rumpi]

Saturate all exposed edges (holes included) with thin cyanoacrylate (aka. Superglue), then paint. It might be prudent to use a harder ply like meranti or sapeli, the weight increase is minimal for a table.