Plywood

Currently stocking Mourikis – European Gaboon plywood.

Mourikis BS1088:2018 LR Approval Cert.

We don’t carry large quantities of all thicknesses, so please contact us for stock levels prior to ordering.

To purchase multiple sheets of varying sizes, please select a thickness, input quantity desired of thickness selected, and add to cart. Repeat this process for different thicknesses.

Each order to be shipped requires packing, this includes protective sheets (MDF/Ply), strapping, plastic wrapping, and cardboard protectors. Please be sure to add this to your cart (once). Only local pickup can opt for no packing, you will need to provide your own packing/protection.

Please note – local pickup is free, however shipping is not calculated automatically as freight charges are tailored to suit individual orders, a subsequent invoice will be sent after you have placed your order.

When comparing prices, be aware that European sheet sizes are larger than most at 2500 x 1220 which is 3.05 square meters compared to 2.88 square meters for a metric standard sheet of 2400 x 1200.

Freight to any mainland destination is very competitive and becomes more-so the larger the order. Sometimes we are able to combine orders to the same destination to save on freight. We have shipped thousands of sheets of plywood all over Australia including to Darwin, Perth, Brisbane, Adelaide, Melbourne and Sydney plus a host of regional destinations as well. Once you have completed checkout we will be in touch with a shipping invoice that will need to be paid prior to the shipping of any goods.

Please note all prices are subject to change at any time without notice.
Bulk buy discount on large orders available (min pack qty apply).

BS1088 INFORMATION

It is important when buying timber for your project that you are informed about what you are purchasing so you end up with the best products for your boat.

For those looking to build a boat using marine plywood in Australia there are a number of options to choose from but not many in the lightweight category.  The choice of many boat builders for years has been a ply made from an African hardwood called Okoume or Gaboon.

What exactly is Gaboon marine ply?

Gaboon or Okoume (Aucoumea klaineana) is a medium sized hardwood native to equatorial West Africa.  Its major use is in the production of plywood.  In its plywood form it has been used extensively in boat building and is still used in the manufacture of lightweight aircraft.  Gaboon is one of the species that can be used to make lightweight marine ply under the British Marine Plywood Standard BS1088-1:2003.  Gaboon’s air dried density is around 430-480kg per cubic meter as opposed to hoop pine which is around 530-560kg per cubic meter.

MARINE PLYWOOD STANDARDS

For boatbuilding in Australia, the two marine plywood standards most commonly encountered are AS/NZS 2272:2006 (reconfirmed 2016) and the British Standard BS 1088:2018 – Marine plywood – Requirements.

BS 1088:2018 replaced the former BS 1088-1:2003 and BS 1088-2:2003 standards.

Both AS/NZS 2272 and BS 1088 establish detailed requirements for the materials, construction, bonding and quality of marine plywood. A sheet carrying the word “marine” is not necessarily equivalent to plywood manufactured in accordance with one of these standards.

Standard and Lightweight BS 1088 plywood

BS 1088:2018 recognises two classes of marine plywood: STANDARD and LIGHTWEIGHT.

Standard marine plywood is manufactured from timber species having a nominal density greater than 500 kg/m³ at 12% moisture content and meeting the required natural durability classification.

Lightweight marine plywood uses species having a nominal density of 500 kg/m³ or less and meeting the durability requirements specified for that class. Gaboon or Okoume (Aucoumea klaineana) is specifically recognised as an example of the type of lower-density timber used in lightweight marine plywood.

Gaboon marine plywood has been widely used in lightweight wooden boat construction because of its favourable strength-to-weight ratio, workability, consistent machining characteristics and ability to produce high-quality finished surfaces.

What does BS 1088 actually require?

BS 1088 is considerably more than a waterproof glue specification.

Among other things, the standard controls veneer quality, timber durability, panel construction, veneer thickness, manufacturing defects, dimensional tolerances, moisture content and glue-bond performance.

For panels more than 3.8 mm thick, the outer veneers must each be at least 1.0 mm thick after sanding, while individual inner and core veneers must not exceed 4.8 mm.

Panels up to and including 6.5 mm thick must contain at least three plies, while thicker panels require at least five.

The plywood must also have a balanced construction. Corresponding layers either side of the centre of the panel must be appropriately matched in thickness and timber characteristics, with adjacent veneers normally laid with their grain directions at right angles.

Core gaps and manufacturing defects

One of the significant practical differences between properly manufactured marine plywood and cheaper plywood is the quality of the core.

BS 1088 does not permit manufacturing defects such as open core gaps, overlaps or pleats in the veneers, blisters, hollows, sanding-through or missing material at panel edges.

This is particularly important in boatbuilding. Core voids may not be visible until a panel is cut, scarfed or machined, and can produce local weaknesses and pathways for moisture ingress.

Face veneer quality

Cheap plywood is often manufactured with extremely thin decorative face veneers. These can be sanded through during normal preparation, exposing the glue line or underlying core.

BS 1088 prevents this on panels over 3.8 mm thick by requiring the outer veneers to remain at least 1.0 mm thick after sanding.

The standard also places strict limits on defects in the outer veneers. For example, no more than six pin knots per square meter of panel surface are permitted, and repairs to the outer veneers are not permitted.

Glue penetration and clear finishing

Excessive glue bleed-through can make plywood unsuitable for clear finishing.

Under BS 1088:2018, glue penetration through to the surface is only permitted adjacent to otherwise allowable defects and is limited to a maximum of 5% of the area of each outer ply.

We have inspected nominally “marine” plywood where glue bleed-through was visible over large areas of the face veneers. Apart from raising questions about compliance, this can make an otherwise attractive sheet effectively useless where a clear timber finish is required.

Bonding quality

Marine plywood manufactured to BS 1088:2018 must meet Bonding Class 3 of BS EN 314-2, with bonding quality tested in accordance with BS EN 314-1.

BS EN 314-2 Class 3 certifies the durability of the plywood’s adhesive bond under exterior exposure conditions. It does not, by itself, certify the plywood as marine plywood.

The older BS 1088-2 knife-test standard used with BS 1088-1:2003 has been withdrawn and is no longer part of the current BS 1088 compliance system.

BS 1088:2018 is principally performance-based in relation to the glue bond. Suitable adhesive systems can include phenolic, qualifying melamine-formaldehyde systems and pMDI (polymeric methylene diphenyl diisocyanate), provided the finished plywood achieves the required bonding performance.

How should BS 1088 plywood be marked?

A panel represented as complying with BS 1088:2018 should be indelibly marked on its edge or back.

The marking identifies:

• BS 1088:2018 and MARINE;
• whether preservative treatment has been applied, identified by PT;
• the nominal thickness in millimeters;
• the manufacturer or manufacturer’s identification mark;
• the country of manufacture using its two-letter country code;
• whether the plywood is STANDARD or LIGHTWEIGHT; and
• the predominant timber species.

The accompanying consignment documentation should also identify all timber species used in manufacture and details of any preservative treatment.

A vague stamp simply saying “BS1088 Marine Ply” is therefore not the marking system specified by the current standard.

Compliance versus independent certification

An important point for purchasers is that marking a product BS 1088:2018 is fundamentally a manufacturer’s declaration that its product complies with the standard.

That declaration is not, by itself, independent third-party certification.

For this reason, when purchasing plywood for a significant boatbuilding project we recommend asking the supplier what evidence supports the BS 1088 claim. Depending on the product this may include independent certification, manufacturer compliance documentation and current testing records.

A reputable supplier should be able to identify the manufacturer and product, explain which standard it is manufactured to and provide supporting documentation.

Ply ain’t ply

Over many years of building wooden boats we have seen plywood sold as “BS1088 marine plywood” displaying extremely thin face veneers, core voids, inconsistent internal timber species, glue-line failures, excessive glue penetration and poor-quality panel construction.

Some of these faults become obvious as soon as the panel is machined. Others may not appear until well into a boatbuilding project.

Marine plywood represents a relatively small proportion of the total cost of most boatbuilding projects but forms a fundamental part of the structure. Saving money by using questionable plywood can become very expensive once hundreds of hours of labour and thousands of dollars of epoxy, fibreglass, timber and fittings have been added to it.

Whoever you buy your plywood from, ask what standard it complies with, who manufactured it and what evidence is available to substantiate the claim.

If a supplier selling BS 1088 plywood is unfamiliar with BS 1088:2018, that in itself is worth asking further questions about.

Bonding Class 3 testing

The Class 3 conditioning is quite severe.

For exterior/Class 3 evaluation, EN 314-1 subjects specimens to severe moisture and heat conditioning before the shear test. Commonly referenced Class 3 pre-treatments include:

• Immersion in water for 24 hours at about 20°C;
• A boil-dry-boil sequence: roughly 4 hours boiling, 16-20 hours drying at 60°C, another 4 hours boiling, followed by cooling in water; and
• The most severe procedure: 72 hours continuously in boiling water, followed by cooling in water before testing.

These procedures are described in research applying EN 314-1/314-2 Class 3 testing.

This means Class 3 is substantially more meaningful than simply calling an adhesive “waterproof”. The finished glue line in the plywood has to retain adequate bond performance after severe wet and boiling conditioning.