Re: Which side of AC plywood to face outward?

Hi Dan,

> If building a plywood boat where the exterior of the hull (but not

the

> interior) is to be covered with fiberglass cloth and epoxied, it

would

> seem to make sense to face the poorer side of AC exterior grade
> plywood outward. That way imperfections on the exterior can be filled
> and the fiberglass/epoxy should prevent or greatly reduce any

checking

> and protect the surface.

That's exactly how I've done it, too. Works great with this
AC "Superply" I've found, since it has a nice luan A-side for a smooth
paint finish with little effort. If the interior face is fir, you may
still wind up with checking, however. The exterior should hold up for
years with glass/epoxy sheathing.

Jon Kolb
www.kolbsadventures.com/boatbuilding_index.htm

Depending on boat size AB with the A to the inside could save a lot
of time for a few bucks more or for that cost use MDO. Epoxys good
and paints great but then to me encapsolation is still better. Eather
way coat with epoxy then glass on fir plywood.

Jon

--- Inbolger@yahoogroups.com, Rick Bedard <sctree@...> wrote:
>
> I've done exactly this on several boats, works great. Good idea to
fill and fair the biggest imperfections just before sheathing the
exterior. I even router out any big hard knots then fill with
epoxy/woodflour.
>
> Rick
>
> Daniel Stewart <stewartd@...> wrote:
> If building a plywood boat where the exterior of the hull
(but not the
> interior) is to be covered with fiberglass cloth and epoxied, it
would
> seem to make sense to face the poorer side of AC exterior grade
> plywood outward. That way imperfections on the exterior can be
filled
> and the fiberglass/epoxy should prevent or greatly reduce any
checking
> and protect the surface.
>
> The unfiberglassed and better interior surface can then be painted
> without much further preparation.
>
> Any comments? Payson (Build the New Instant Boats) doesn't
> specify--or, at least, I can't find any mention.
>
> Thanks, Dan
>
>
>
>
>
>
> [Non-text portions of this message have been removed]
>

I've done exactly this on several boats, works great. Good idea to fill and fair the biggest imperfections just before sheathing the exterior. I even router out any big hard knots then fill with epoxy/woodflour.

Rick

Daniel Stewart <stewartd@...> wrote:
If building a plywood boat where the exterior of the hull (but not the
interior) is to be covered with fiberglass cloth and epoxied, it would
seem to make sense to face the poorer side of AC exterior grade
plywood outward. That way imperfections on the exterior can be filled
and the fiberglass/epoxy should prevent or greatly reduce any checking
and protect the surface.

The unfiberglassed and better interior surface can then be painted
without much further preparation.

Any comments? Payson (Build the New Instant Boats) doesn't
specify--or, at least, I can't find any mention.

Thanks, Dan






[Non-text portions of this message have been removed]

If building a plywood boat where the exterior of the hull (but not the
interior) is to be covered with fiberglass cloth and epoxied, it would
seem to make sense to face the poorer side of AC exterior grade
plywood outward. That way imperfections on the exterior can be filled
and the fiberglass/epoxy should prevent or greatly reduce any checking
and protect the surface.

The unfiberglassed and better interior surface can then be painted
without much further preparation.

Any comments? Payson (Build the New Instant Boats) doesn't
specify--or, at least, I can't find any mention.

Thanks, Dan