Marine Grade Plywood for Hatchboards ?

[SvenG]

Our current solid-wood hatch-boards are salvageable but I'd like to replace them rather than just refinish them.

Is marine grade teak plywood (with solid teak edging) serviceable in a hatch-board application or should I go out and get some more solid teak ?

My main concern is that the veneer might be too thin for daily wear and tear and that even marine grade plywood might not do well under exposed saltwater conditions.

Thoughts ?

Thanks,



-Sven (and NancyJG)

[Mark Johnson]

Teak ply is not meant for exterrior applications at all. The best is to use an exterrior grade of imported metric Okume ply. (like = to 3/8") If you use good quality ply & Mahogany or fir for the combing & frame, then epoxy glass it properly, followed with LP paint... It will be superrior to factory hatches, with an indefinite lifespan, at half the weight, but many times the labor.
Good luck with it! Mark

[SvenG]

Hi Mark,

Originally Posted by Mark Johnson

Teak ply is not meant for exterrior applications at all.

Nice work you have done there, but I was talking about hatch boards, as in companionway drop-in hatch boards, not hatches.

Maybe I used the wrong terms ?

Thanks,



-Sven

[Efraim]

Originally Posted by SvenG

Maybe I used the wrong terms ?
-Sven

They're called washboards.

[Mark Johnson]

Hi Sven,
Sorry for the confusion. Your dropboard options are:

Varnished teak boards (= regular maintenance & heavy)

"Starboard" type of plastic board (= easy to make & 0 maintenance, but VERY heavy)

Glassed / epoxied, & LP painted plywood (= time consuming to make, but only paint every 10 years for maintenance, and fairly light compared to the above)

Glassed / epoxied, & LP painted lightweight foam cored composites (= Very time consuming & a bit expensive to make, but only paint every 10 years for maintenance.)
Being VERY light weight, they have less inertia... this makes them far easiest & quickest to put in and out without dinging them or the boat. This & the light weight matters on Multihulls, racing boats, or boats that put their boards in many times per day! I plan to re-make my ply / epoxy ones, for foam cored dropboards soon.

Hope this helps... Mark

[cburger]

Originally Posted by SvenG

My main concern is that the veneer might be too thin for daily wear and tear and that even marine grade plywood might not do well under exposed saltwater conditions.

-Sven (and NancyJG)

The answer to your quetion is yes, the surface veneers on marine plywood are paper thin and norml use will have it looking bad no time. I would bet you can have your old hatch boards clened up in no time. Find someone to run them thoiugh a joiner planer and remove very small amount of wood for a simple resurface, a good quality belt sanded works also.

[Hudson Force]

It always interests me to hear the different terminology..... washboards.... dropboards,- we always called them crib boards.

Mark, what beautiful craftmanship displayed in your photos! - and good advice.

I selected another option for my old crib boards. Mine were not pretty, but still sound and strong when needed for offshore passages. At other times we have them dropped into the bottom of our hanging lockers where they make a barrier to secure light storage within the base of these lockers. At port, anchorage or cruising in protected waters we use a decorative crib board that adds light below.

[mike d.]

or you could use Philipine Mahogany much lighter in wt and color than Honduras.
easier to work, and takes a finish real well. will turn golden with a clear finish on it. i would seal it with epoxy, then put varnish or urethane over the epoxy to keep the gloss

[Boracay]

I'm using ply washboards, saturated in epoxy with the epoxy protected by single pack polyurethane. They've held up well so far though I still have to add some kind of retainer so they can't fall out.

A few thoughts:-
* Teak edging may be a weak point. It's going to be hard to glue on well and screws could weaken the structure.
* The plywood needs to be knot free and have an "A" grade bond.
* The suggestion about glassing over the edges has much merit. Strengthens the structure.
* Have you considered carbon fibre as a reinforcement rather than glass?
* If the existing boards are sound why not refinish them? If you must have fancy new ones keep the old as backups.
* Several sheets of ply bonded with marine grade glue could be stronger, and the desired thickness could be controled more accuratly.