Greg Luckett Posted February 9, 2003 Report Share Posted February 9, 2003 I first posted this in the B&B forum, which Capt.Jake kindly replied to, but I wonder if there is more advice and/or opinions about this material. Thankyou, Greg Luckett Quote Link to comment Share on other sites More sharing options...
Russ Sylvester Posted February 10, 2003 Report Share Posted February 10, 2003 Don't know what Keruing is, I've never heard of that before. I do know what marine grade is and in my opinion it is a waste of money in this application. Unless you have a specific need for extra plys and (supposedly) no voids then you're just throwing your money away. You can do just as good with ABX and even ACX if your willing to pick through. Quote Link to comment Share on other sites More sharing options...
Greg Luckett Posted February 10, 2003 Author Report Share Posted February 10, 2003 Russ, Thankyou for your opinion, but I would like specific information about the Keruing product. I have built boats with exterior grade plywood, and will do so again when the design warrants it. Greg Luckett Quote Link to comment Share on other sites More sharing options...
Guest BarryPyeatt Posted February 10, 2003 Report Share Posted February 10, 2003 Marine Plywood Keruing Characteristics Keruing & Allied Timbers -------------------------------------------------------------------------------- CHARACTERISTICS OF KERUING MARINE PLYWOOD The weight of a species is a broad guide to its performance. Lighter weight species are softer, less durable, and less strong. Heavy species can exhibit very high levels of strength, natural durability, and toughness. Woods like Okoume/Gaboon are soft and light and rated as non-durable (5 years). Keruing on the other hand is hard, heavy, and rated moderately durable (10 years). Keruing Marine Plywood is the strongest plywood manufactured to BS 1088 on the Market today. Refer to the test procedure prepared by Thorpe Engineering for Resources International. It may be possible to reduce the thickness used. For example: Keruing 5/8" could be stronger, similar in weight, and less expensive than the 3/4" plywood you are using resulting in a superior product at less cost. Interlocking grain naturally rough is important for chemical bonding with a variety of glues, epoxies, and polyesters. The need to scuff sand is reduced or eliminated completely. Because of the interlocked grain Keruing will not check like fir plywood. Fastening holding power of Keruing Plywood is exceptional. Patches: Face and Back - None Core Voids: None When evaluating quality plywood, one of the most important comparisons is the amount of inter-plys. Compare our price for 1/4" Five-Ply, and our price for 1/2" Seven-Ply to the plywood you are using. Keruing is truly the only marine plywood on the market today with quality characteristics tough enough to replace fir marine plywood. Both fir and Keruing are Group 1 woods rated moderately durable. -------------------------------------------------------------------------------- KERUING AND ALLIED TIMBERS Distribution and Supplies Timber of the keruing type, produced by more than seventy species of Dipterocarpus, occurs in parts of India and Pakistan, Ceylon, throughout South-East peninsular Asia, and in Sumatra, Borneo and the Philippines. The timber is known by distinctive names according to its origin; among the more important are keruing (Malaya, Sarawak, Sabah and Indonesia), gurjun (India and Burma), yang (Thailand), apitong (Philippines). The general characters of the timbers from the different countries are similar but where the timber is produced by comparatively few species, as in Burma and Thailand, shipments tend to be more uniform in character than those from countries such as Malaya and Sabah, with a large number of species. The trees commonly reach a large size, 30-60 m. (100-200 ft.) in height, with a straight, cylindrical bole 0.9-1.8 m. (3-6 ft.) in diameter. The timber is in good supply. In Britain it is available in the form of graded lumber, 25-150mm. (1-6 in.) thick, 100-350 mm. (4-14 in.) wide, in lengths of 1.8-6.0m. (6-20 ft.) or more, average about 4.25 m. (14 ft.), and as flooring strips. Logs are 300-750 mm. (12-30 in.) in diameter and 3.5-12.0 mm. (12-40 in.) long. General Description A timber of plain appearance, varying in color and density according to species. The heartwood is pinkish-brown to dark-brown, sometimes with a purple tint, usually distinct from the pale sapwood. In the seasoned condition the density is mostly in the range 0.72-0.80 (45-50 lb./ft - see item # 3 below), i.e. comparable to English Oak or a little heavier. The grain is straight or slightly interlocked; the texture typically rather coarse. The timber is remarkably free from defects, though resin exudation is liable to mar the surface of the wood, particularly when it is exposed to direct sunlight or radiant heat. Seasoning and Movement Keruing and allied timbers dry rather slowly. There is a tendency for distortion and collapse to occur. To reduce the risk of resin exudation in service, the timber may be raised to a high temperature in the kiln to drive off the volatile component. Any resin that comes to the surface during seasoning can be cleaned off before the timber is used. FPRL kiln schedule D is recommended. Dimensional movement in service is classed as large. Strength and Bending Properties On average, the timbers of this group are some 40 percent stiffer than oak and 20 percent superior in bending and compression. They are considered unsuitable for steam-bending work. Durability and Preservative Treatment The heartwood is moderately durable against fungal attack but is susceptible to termites. It is rated moderately resistant to preservative treatment. Working and Finishing Properties In the green condition the timber can be sawn and machined without serious difficulty, but once dried it often gives trouble, owing to the silica content. The use of tungsten carbide tipped tools, especially saws, is advisable. It can be machined to a clean, if slightly fibrous, surface; where the grain is interlocked, the finish of quartered surfaces is improved by reducing the cutting angle to 20 Quote Link to comment Share on other sites More sharing options...
Barry Pyeatt Posted February 10, 2003 Report Share Posted February 10, 2003 "Why Pay More When the Best is Less?" -------------------------------------------------------------------------------- Keruing Marine Plywood Please call (360) 871-8650 or Fax (360) 871-8652 Description: Marine Grade Plywood AA Panel Construction: 100% Keruing Veneers Strength Factor: Keruing may be the strongest marine plywood made in the world. Keruing marine grade panels are manufactured to meet or exceed British standard BS 1088 WBP. As a specie, Keruing is considered moderately durable, placing it in the same classification as African Mahogany and Douglas Fir. The strength factor of Keruing compaires favorably with Khaya and Honduras Mahogany. Keruing panels have a wide variety of applications, not limited to marine use. Rotary cut Keruing plywood can be used in any building project where a top of the line marine grade panel is required. Millimeters Inches Ply Weight Per Sheet Cost Per Sheet 2mm 5/64 3 11 lbs. $30.10 3mm 1/8 3 16.5 lbs. $34.50 4mm 5/32 3 22 lbs. $40.50 6mm 1/4 5 29 lbs. $54.95 9mm 3/8 7 45 lbs. $72.55 12mm 1/2 9 60 lbs. $94.55 19mm 3/4 11 90 lbs. $116.40 Available in 4' x 8' sheets only Volume Orders - 5% discount for 10 sheets or more FOB: Tacoma, Washington Quote Link to comment Share on other sites More sharing options...
Barry Pyeatt Posted February 10, 2003 Report Share Posted February 10, 2003 This plywood is available from other dealers around the US. I have talked with a couple builders that have used it in fresh water applications. They were pleased with the workability of the wood and its ability to finish out nicely. They both glassed over it and reported that they had no problems with it at all. Neither have had any length of time to evaluate its maintenance characteristics but they liked the way it held fasteners. Quote Link to comment Share on other sites More sharing options...
Greg Luckett Posted February 10, 2003 Author Report Share Posted February 10, 2003 Lots of good info. Thankyou Barry. Does it tend to check like fir does? Quote Link to comment Share on other sites More sharing options...
capt jake Posted February 10, 2003 Report Share Posted February 10, 2003 From what I have heard and by looking at a piece of it, no it doesn't check like Fir. It looks almost like a Luan, as far at the grain. it is fairly dense and tight grained. Quote Link to comment Share on other sites More sharing options...
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