William R. Watt wrote:

I'm never sure when people mention 1/4" lauan what they mean. All we have
in Ottawa is the lauan underlayment, a low quality product with a thick
inner ply and two thin face plys. Its close to 1/4" but is actually metric
(5.22 mm?) and closer to 1/5". Its what the boat I have is made of. If you
find a regular 3 or 5 ply lauan plywood it would likely be better. I've
also read in this newsgroup of a better quality lauan plywood called
meranti available in some parts of the USA. The 1/5" underlayment that
I've used weighs about the same as the okume marine of similar thickness,
half a pound a square foot, or 17 pounds for a 4 x8 sheet.


For years, the local (mid-atlantic USA) lauan was the 3 ply stuff you
mention... minor voids (which can be filled in various ways if wanted
but usually it isn't big enough to worry about) and only one real
useable (for show) side. Recently (the past 2 years) it has a label
"Meranti" on it and I've wondered what it is. It is basically the same
plywood but the coloring of the wood is more variable, from yellow (like
birch) to more reddish like mahogany.

I've used both for repairs on boats (and regular interior and exterior
projects) and it holds up fine if painted (including varnish or
polyurethane) and maintained. For small utility type boats, the thing
I've picked up is to 1) install plenty of rub rails (pref. oak) and 2)
keep paint handy so when it gets scuffed (to the point where wood is
exposed) it can be touched up.

Ed