OKOUME:
Aucoumea klaineana (Angouma, Gaboon,
or Okoumé) is a
tree in
the family
Burseraceae, native to equatorial west
Africa
in Gabon,
the
Republic of the Congo, and
Rio Muni. It is a medium-sized
hardwood
tree
growing to 30-40 m tall, rarely larger, with a trunk 1-2.5 m
diameter above the often large basal buttresses. The tree generally
grows in small stands, the roots of the trees intertwined with
neighboring trees. In Gabon it is the primary
timber species. Okoume weighs approximately 450-500kg/m3. It is
a non-durable specie with low decay resistance and moderate
dimensional stability, the major use of Gaboon is in the manufacture
of
plywood.
In the form known as okoume marine grade plywood, it is
considered perhaps the finest construction plywood now available for
boats. It is widely available manufactured and certified to British
Standard 1088. It's users range from individual hobbyist kayak
builders to some of the world's largest boat builders. Most often it
is used in combination with epoxy and fiberglass, the combination
giving a structure that can be stronger and lighter than plastic or
fiberglass, rivaling the performance characteristics of more
advanced composites such as carbon fiber. The grain appearance is
prized, likened to that of mahogany and is often varnished for a
decorative appearance.
 This
is a picture showing the core composition of okoume BS1088 plywood.
This example is of 12mm (1/2") 9-ply material.
HYDROCORE:
Available in Gurjan or Meranti, it is a lower priced option to
Okoume or Sapele. Although these species are heavier in weight and
subsequently more durable, they are excellent choices for areas
under the water line, hatch covers, transoms, or areas where higher
durability and strength superceed lightweight advantages.
Here's a bit more about the species used to make Hydrocore
plywood:
Gurjan
(Dipterocarpus) is a genus of
flowering plants and the type genus of family
Dipterocarpaceae. The genus has about 70 species, occurring in
Southeast Asia. It is an important component of
dipterocarp forests. Its generic name comes from
Greek and means "two-winged fruits". This specie tends to be
much heavier than other options and subsequently has its various
pros and cons. This specie is available with a rot resistance
treatment comprised of copper sulfate, allowing it to out-perform other marine plywoods in areas prone to come into contact with water
somewhere down the line... transoms, windows, hull bottoms, etc.
Gurjan is also available with fire retardant treatment to a Class A
rating, performing with a flame spread of 25 and under. Certified by
Lloyd's, this panel is ideal for commercial, military and
transportation requirements demanding the panels to be certified for
international travel.
This is a
close-up of the Gurjan core. You can see it is void free and has a
very solid composition. This material is certified by Lloyd's as
BS1088.
The genus is of considerable importance as timber trees, sold
under the trade name
Keruing, although not as important as
Shorea.
Meranti
(also known as Philippine Mahogany)
(Shorea)
Shorea is a
genus of about 196
species of mainly
rainforest
trees in the
family
Dipterocarpaceae. They are native to southeast
Asia, from Northern
India to
Malaysia,
Indonesia and the
Philippines.
Many economically important
timber trees belong to Shorea. They are sold under
various trade names including "Meranti", "Lauan" (or "Luan"), "Seraya",
"Balau", and "Bangkirai". The alluringly-named "Philippine
Mahogany" sold in North America is not a
mahogany at all, but actually a mixture of woods from the
genus Shorea. Non-timber products from Shorea spp.
include
Dammar and
Illepe. Dammar, the resin from Dipterocarps, is collected
from a variety of species. It various in colour among the
different taxonomic groups. Shorea wiesneri is listed on
many websites as an important source of dammar, however, this
appears to be either a trade name or a synonym.
Meranti is an excellent option for classic boat repair.
Although the grain is hard and tends to splinter if not cut with
quality blades, it holds up much better than douglas fir, as it
is not as brittle and does not have core imperfections or face
plugs which tend to take away from the structural stability and
performance of the panel. When BS1088 grade is available for
about the same price as a domestic fir (which is made to an
inferior standard than BS1088), it is a no brainer.
SAPELE
Sapele, Sapelli or Aboudikro (Entandrophragma
cylindricum) is a large
tree,
up to 45 m high (rarely 60 m), native to tropical
Africa.
The commercially important
wood is
reminiscent of
mahogany, with a distinctive figure, typically applied where
figure is important. It is sought after as flooring for its
durability and beautiful graining. As Stage-ply, it is vastrly used
by stage production companies in the construction of sets for well
known boradway musical performances.
Besides Boat Building and flooring applications, its more exotic
uses is that in guitar manufacturing and wood trim accents in luxury
vehicles. This specie can be regarded as the Rolls-Royce of marine
plywoods due to its excellent structural and physical properties,
making it the ideal option for hull construction.
This is a picture of the core of BS1088 Sapele 18mm 13-ply.
EuroLite
Made of 100% Lightweight European poplar and
weighing about 1/3 of conventional plywood (410-440 KG/m3), EuroLite
offers builders a lesser expensive option for interior cabinetry and
non-structural applications. Defects are clipped off core veneers
and edge-glued to provide a solid composition suitable for precision
and CNC (Computer Numerical Controlled) cutting. Although this
plywood is not recommended for structural applications, some of our
customers have had positive results with certain projects.
 Eurolite 6mm 5-ply
POWERPLY
Marine Powerply is manufactured from the best quality 100% Gurjan
hardwood with high stiffness and strength. It is bonded with phenol
formaldehyde resin and is subjected to permanent preservative
treatment by vacuum impregnation. This makes it resistant to marine
borer attacks and enables it to withstand saline water.
Properties
Powerply has high impact strength that can tolerate turbulent
conditions
Rigid and wear resistant
It can withstand alternate wetting and drying
Application
Ship floors and boats
Lining for refrigerated ships
Cargo hold covers
Life boats, motor boats and mine sweeping crafts
Cooling towers
 This
is a close-up of the Powerply core.
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