Specific Gravity is a comparative measurement of a materials density to that of water. Water is used as a base line for specific gravity and is given a value of 1. All other materials are compared to water and expressed as a ratio heavier or lighter in density. As specific gravity is a comparison tool, it can be applied across any units of any material. Lumber with a specific gravity of greater than 1.0 will sink in water. Lumber with a specific gravity less than 1.0 will float. As specific gravity drops farther below 1.0 buoyancy increases

The density of pure water is 62.4 lbs/cu.ft (pounds per cubic foot) and if a sample of apple has a specific gravity of 0.73 then we can calculate that its density is 0.73 x 62.4 = 45.552 lbs/cu.ft.
Note, kg/cu.m divided by 16.01846 = lbs/cu.ft.

While this measure is similar to lbs/cu.ft. it is good to know the meaning of this measurement as it is commonly used in the timber/lumber to describe wood characteristics.

See the chart below for species information about specific gravity.

For more information  see the Wood Products Handbook

Chamaecyparis nootkatensis- Alaska cedar, Alaska cypress, Alaska yellow cedar,, Nootka cypress,, Pacific Coast yellow cedar, Found in coastal forests from southwestern Alaska to northern California. The sapwood is narrow and slightly lighter than the bright, clear yellow heartwood. It has a slight odor best described as "raw potatoes". The wood is moderately heavy, soft, fine textured, straight grained, easily worked and durable. It is rated as moderate in strength, stiffness, hardness and shock resistance The timber of Alaska cedar is readily worked by both hand and machine tools. In lumber with a wavy grain, there is a tendency for the grain to pick up in planning and molding. Alaska cedar is rated as resistant to very resistant to heartwood decay. Used locally for interior trim, furniture, small boat hulls and canoe paddles, dock decking, carving, cooling towers, framing, furniture, heavy flooring, marine piling, molding, musical instruments.

Recommended use: may be used as a primary material in any paddle. This species is one of my favorites however; as the hardest of the cedar species it is rather heavy. Alaskan cedar is great as a hardwood tip, blade edge, grip or loom laminated material. Alaskan cedar may be add to increase stiffness to a paddle. This species is excellent for single blade paddles as a primary material. This species is in limited supply and is priced slightly higher then other cedar species and may not be available at various times.

Availability: very limited,  limited renew ability , we will provide this species in the future only when salvage lumber is available

Fraxinus Americana- The American ash is native to north temperate regions of the globe. The sapwood of ash is light brown, while the heartwood is brown to grayish brown. . It has no characteristic odor or taste. Ash is straight grained, heavy, hard, strong, stiff and wears smooth with high shock resistance. It machines well and glues moderately well. Ash is classed as slightly to non-resistant to heartwood decay. Ash is commonly used in handle stock, baseball bats, un-upholstered furniture, flooring, millwork, hand tools, sporting goods, boxes and crates.

Recommended use: as a thin single layer in a paddle to add strength or protect against abrasion on the edges of a paddle, suitable for hardwood tips. May be used in single blade paddles more extensively then in Greenland paddles because of its weight.

Availability: Widely available from renewable sources

Recommended use: may be used as a primary material in any paddle. This species is very light and flexible but very soft and you may want to add protective tips and edges to a paddle of this material. This species is very decay resistant and looks beautiful. We use Atlantic white cedar in most paddles.

Availability: Moderate available, from local renewable sources

Tillia Americana- The natural range of American basswood is from New Brunswick to southeast Manitoba and, south to Oklahoma and east to North Carolina. The sapwood of basswood is white to cream, while the heartwood is pale to reddish brown, with darker streaks. When dry, the wood has no characteristic odor or taste. The wood is soft and light, with a fine, even texture. American basswood works easily with tools, making it a premier carving wood. Rated as slightly or nonresistant to heartwood decay. Uses: Lumber, veneer, plywood, carvings, pulp, decoys, fiber products, furniture stock, mobile homes, shade rollers, signs, toys, sporting goods, wooden ware, and novelties.

Recommended use: may be used as a primary material in any paddle but may not be laminated to some species.

Availability: Moderate available, from renewable source

Betula spp.- Birch is found principally in the northern and eastern united states. Yellow birch are the source of most birch lumber and veneer. The wood of yellow birch is heavy, hard and strong, All birches have a fine, uniform texture. yellow birch is difficult to work with hand tools and difficult to glue, but easily machined. Yellow birch has white sapwood and light reddish-brown heartwood. Rated as slightly or nonresistant to heartwood decay. Yellow and sweet birch lumber and veneer are used principally in the manufacture of furniture, boxes, baskets, crates, wooden ware, cooperage, interior finish, and doors. (birch usually is much whiter then the picture indicates)

Recommended use: may be used for hardwood tips or as a thin strip to protect the blade edges from abrasion.

Availability: Widely available from renewable sources

Brosimum Rubescens, also called Muirapiranga, Satine Rubane, Cardinal Wood, is found in the Amazon basic and the Guiana's. The heartwood is blood red in color and ages to a deep brown color. Lacquer extends aging to help preserve red color.  High bending and crushing strength. Medium stiffness and resistance to shock, but tends to splinter and has low steam bending characteristics. Blood wood is hard and heavy although it can be worked nicely you will need to sharpen your took before and after working with this species. Blood wood is durable, stable and very rot resistant. Common uses are Cabinetmaking, furniture, decorative inlay, turning, veneers.
 

Recommended use: paddle tips, blade edges and accents strips in paddles

Availability: A tropical hardwood of limited renew ability, We purchase it as scraps from boat builders and cabinet shops to limit our environmental impact.

Recommended uses: may be used as a thin single layer in a paddle to add strength or protect against abrasion, suitable for hardwood tips. The deep rich color of cherry can greatly enhance the appearance of a paddle. In single blade paddles cherry may be used as a primary material.

Availability: Widely available from renewable sources

Juglans nigra -American walnut, black walnut Black walnut is native to the eastern United States, from southern Minnesota east to, New York; south to Florida, west to Texas.. The sapwood of black walnut is nearly white, while the heartwood is light brown to dark, chocolate brown, often with a purplish cast and darker streaks. The wood is heavy, hard, and stiff and has high shock resistance. Black walnut is straight grained and easily worked with hand tools and by machine. It finishes beautifully and holds paint and stain exceptionally well. It also glues and polishes well. Rated as very resistant to heartwood decay–one of the most durable woods, even under conditions favorable to decay. Uses: Furniture, fixtures, cabinets, gunstocks, novelties, interior paneling, veneer.

Recommended uses: may be used as a thin single layer in a paddle to add strength or protect against abrasion, suitable for hardwood tips and to protect blade edges. The deep rich color of Black Walnut can greatly enhance the appearance of a paddle. May be used in single blade paddles as a primary material.

Availability: Widely available from renewable sources

One of several species Guibourtia arnoldiana, also called benge, Guibourtia ehie, called ehie or ovangkol  and, , Guibourtia spp. called bubinga all from West Africa and varying in color greatly from red to brown and yellow. Benge is yellow, ehie is gold to brown, bubinga is pink to brown with black or purple stripes. Ehie is course in texture while  bubinga and benge are fine textured. All types are hard and heavy woods that work well with sharp tools. These are moderately decay resistant species. Common uses are flooring and furniture

Availability: A tropical hardwood of limited renew ability, We purchase it as scraps from boat builders and cabinet shops to limit our environmental impact

Juglans cinera- Butternut is native to the eastern United States from Tennessee and western North Carolina north to southern Ontario and Quebec. The narrow sapwood of butternut is white to light brown, while the heartwood is chestnut brown with red tinges. The growth rings are distinct, with a marked difference between the size of the early wood and latewood pores. Butternut is similar to black walnut, but lighter in color and weight. It has no characteristic odor or taste. Butternut generally has a straight grain, works easily with tools, and takes a rich, lustrous finish. Rated as slightly or nonresistant to heartwood decay. Butternut is used in lumber, furniture, boxes, crates, mill work, veneer.

Recommended use: may be used as a secondary material in Greenland paddles or as a primary material in single blades, this wood is very attractive when finished but is not as durable as many other species.

Availability: Widely available from renewable sources

Juniperus virginiana- Eastern red cedar is native to the eastern half of the. Eastern red cedar has a thin, white sapwood, while the heartwood is red to deep reddish-brown. The sapwood may be in stripes, alternating with stripes of heartwood. The wood is moderately low in strength and stiffness, but it is high in shock resistance. It shrinks little during drying and is good dimensional stability. It is easy to work by machine and has moderate hardness. It can be brittle, but has good and gluing properties. It has tight knots, which can add to the beauty of the wood. The heartwood is highly resistant to decay. The scent of the wood is said to be a natural insect repellent. Eastern red cedar is used in fence posts, chests, wardrobes, closet linings, pencils, carvings, pet bedding, furniture, flooring, and small boats Oil from the wood (cedrol) is used in the manufacture of perfumes and medicines. It is also used for Christmas trees.

Recommended use: This species can be brittle and is always very knotty. eastern red cedar should be used for its appearance not it structural quality. When finished it can look amazing. because of the difficulty in working this species additional charges may be added

also called, Silky-oak, Australian Silky-oak, Northern Silky-oak, Queensland Silky-oak, selena, louro faia, comes from Australia. The heartwood is reddish brown and course textured turning brown with age. On quarter saw pieces large “eye” are visible on this straight grained lumber. Reasonable good working ability with sharp tools. (a reduced cutting angle increase workability.) slight resistance to wear and moderate decay resistance. Commonly use in decorative veneers and specialty items and priced very high in the USA. This wood may cause respiratory problems when cut always wear a mask.

Availability: A tropical hardwood of limited renew ability, We purchase it as scraps from boat builders and cabinet shops to limit our environmental impact

Acer saccharum- sugar maple, found in most of North America,. Maple lumber comes principally from the Middle Atlantic and Lake States. The wood of sugar maple and black maple is known as hard maple; that of silver maple, red maple, and box elder as soft maple. The sapwood of the maples is commonly white with a slight reddish-brown tinge; the heartwood is light reddish brown, but sometimes is considerably darker. .Hard maple has a fine, uniform texture, turns well on a lathe, is resistant to abrasion and has no characteristic odor or taste. It is heavy, strong, stiff, hard, and resistant to shock, and it has large shrinkage. Sugar maple is generally straight grained but the grain also occurs as "birds-eye," "curly," and "fiddle back" grain.. Maple lumber sometimes has olive or greenish black discolored areas known as mineral streak or mineral stain, which may be due to injury. Maple wood stains well and takes a high polish. It is intermediate in gluing and has low decay resistance.

Recommended use: as a thin single layer in a paddle to add strength or protect against abrasion, suitable for hardwood tips. Maple is very heavy and should be used sparingly in most paddles. Maple can be used more readily in single blade paddles.

Availability: Widely available from renewable sources

Quercus spp.- The sapwood of oak is white to very light pinkish brown, while the heartwood is light to reddish dark brown. Oak wood has a course texture; it is heavy, straight-grained, hard, tough, very stiff, and strong. Oak wood has good working properties. It machines and glues well.. Oak finishes well, but shrinks considerably. Oak is commonly used in ships, railroad crossties, timber bridges, tannin dyes, fuel wood, hardwood dimensions and flooring, furniture, veneer, plywood, barrels, kegs and casks (white oak group), truck and trailer beds, mining timbers, containers, pallets, boxes, paneling.

Recommended use: as a thin single layer in a paddle to add strength or protect against abrasion, suitable for hardwood tips.

Availability: Widely available from renewable sources

also called,  Mbe, Mbil (Cameroon), Ngula, Bosulu (Zaire), ranges from central to tropical West Africa and grows in  dense equatorial rain forests, often in small groups. Heartwood vivid orange to red when freshly cut darkening to a purple brown on exposure. Texture coarse; grain straight to interlocked; lustrous; faint aromatic scent when freshly cut. Sawdust may cause respiratory problems. this is heavy and hardwood that is difficult to tool.

Availability: A tropical hardwood of limited renew ability, We purchase it as scraps from boat builders and cabinet shops to limit our environmental impact

Pinus spp.- Botanically, ponderosa pine belongs to the yellow pine group rather than the white pine group. The heartwood is yellowish to light reddish brown or orange and the wide sapwood is nearly white to pale yellow. It is straight grained and has moderately small shrinkage. It is quite uniform in texture and has little tendency to warp and twist. Widely distributed throughout the Rocky Mountains and mountains of the Pacific coast. . It also grows in northern Mexico. Ponderosa pine is not durable unless treated with a preservative, under conditions favorable to decay. It is rated as slightly to nonresistant to decay. Ponderosa pine is used mainly for lumber and to a lesser extent for piles, poles, posts, mine timbers, veneer, and railroad crossties. The clear wood is especially well suited for millwork, such as window frames, doors, shelving, moldings, sash doors, blinds, paneling, mantels, trim, and built-in cases and cabinets. Lower grade lumber is used for boxes and crates. Much of the lumber of intermediate or lower grades goes into sheathing, sub flooring, and roof boards. Knotty ponderosa pine is used for interior finish. A considerable amount now goes into particleboard and paper.

Recommended use: may be used as a primary material in any paddle.

Availability: Widely available from renewable sources

Liriodendron tulipifera- southern yellow poplar, tulip poplar, tulip tree, tulipwood, white poplar, Found in most of the eastern United States. Yellow Poplar sapwood is white, sometimes with stripes, while the heartwood is usually tan, but can range from greenish brown to dark green, purple, black, blue and yellow. The wood is straight grained, uniform in texture and moderate to light weight. Yellow Poplar has the reputation of being one of the easiest of all hardwoods to work with hand and machine tools. It works well in planning, turning, gluing and boring. It holds stain and paint well. Poplar is used for lumber, veneer, pulpwood, furniture, plywood, interior finish, dimension stock, gunstocks, musical instruments, toys, novelties, hat blocks, sporting goods, pallets, shipping crates, slack cooperage, particle board.

Recommended use: may be used as a primary material in any paddle

Availability: Widely available from renewable sources

Chamaecyparis lawsoniana- Lawson cypress, Oregon cedar, Oregon cypress, Port-Orford-cedar, Port-Orford-cedar is native to a narrow zone near the Pacific Coast from southwest Oregon (Lane County and Coos Bay) south to northwest California (Mad River and locally in the Mount Shasta area). The sapwood of Port-Orford-cedar varies from nearly white to a pale yellowish brown The heartwood is yellowish white to pale yellowish brown. The wood has a fine, even texture and the grain is even and straight. It has a characteristic odor (from volatile oils), described as "ginger like" and a bitter, spicy taste. It is moderately light in weight and is stiff, strong, hard and somewhat shock resistant. It shrinks slightly when dried, with little tendency to warp. It works well with tools.. The heartwood is highly resistant to decay. It holds paint and polishes well. It weathers to a light gray, with a silvery sheen, without checks.: Port-Orford-cedar works well with tools. It is rated as resistant or very resistant to heartwood decay. Port orford cedar is used in arrow shafts, storage battery separators, Venetian blind slats, sashes, doors, interior finish millwork, mothproof linings for boxes and closets, boats, matches, general construction, water tanks, bridges, dock planking, railroad ties and mine timbers.

Recommended use: may be used as a primary material in any paddle however is of limited availability and when available, priced slightly higher then other cedar species.

Availability: limited available, limited renew ability

Peltogyne spp,also called amaranth, ranges from the Brazilian Amazon to Mexico. When fresh cut the wood is brownish grey but turns a purple color when exposed to light and  air for a few days. Over time the wood turns dark brown. This is very strong heavy wood. It is very difficult to work with any tools and dulls tools fast. It is very resistant to decay. Always wear gloves when working with this species as you can get some nasty splinters. The dust for the wood is toxic always wear a dust mask when cutting as with all wood species. Common uses are in heavy construction and as for use in poll cues and a accents in  fine wood working.

Availability: A tropical hardwood of limited renew ability, We purchase it as scraps from boat builders and cabinet shops to limit our environmental impact

Dalbergia stevensonii also know as  Palissandre du Bresil (French), Jacaranda de Brasil (Spanish), Cabiuna, Caviuna, Jacaranda (Brazil), ranges are scattered in the eastern forests of Bahia and southward to Espirito Santo and Rio de Janeiro and inland to include Minas Gerais.  Because of long-time exploitation, the tree has become very scarce in the more accessible regions. Other similar species of India rose wood are also marketed. For this reason we seldom use this species unless salvage wood is available. Heartwood is brown to violet irregularly and conspicuously streaked with black. Grain generally straight; texture medium to rather coarse; luster medium; fragrant rose-like odor, taste distinctive but don’t try it again always wear a dust mask when working with wood. Works very nicely, some specimens may be too oily to take a good polish. Very resistant to decay.

Commonly use in fine wood working

Recommended use: rosewood is hard and heavy, it is suitable for handles , tips, grips and accents.

Availability: A tropical hardwood of limited renew ability, We purchase it as scraps from boat builders and cabinet shops to limit our environmental impact

Piecea sitchensis,  also called British Columbia sitka-spruce, coast spruce, great tideland spruce, Menzies spruce, silver spruce, western spruce, yellow spruce. Sitka spruce ranges from southern Alaska (Kodiak Island and Cook Inlet) , along the coast as far south as northern California. The sapwood is a creamy white to light yellow, while the heartwood is pinkish yellow to brown. The wood has a fine, uniform texture and generally has a straight grain. It is moderately light in weight, moderately stiff, moderately soft, and moderately low in resistance to shock. On the basis of weight, it rates high in strength properties and can be obtained in clear, straight-grained pieces. It can be worked easily (when free of knots). It has a low resistance to decay and is resistant to preservation treatments under pressure, but can be treated by a water diffusion process. Thin panels of Sitka spruce are highly resonant, making them desirable for piano sounding boards. Common uses include lumber, pulpwood, sounding boards for high quality pianos, guitar faces, ladders, components for experimental light aircraft, oars, planking, masts and spars for boats, and turbine blades. Working with fresh cut lumber my cause irritation wear protective clothing and a mask.

Availability: Moderate available, renew ability unknown

The term Spanish cedar refers to a group of 6 or more species in the Cedrelo genus that are distributed from southern Mexico to northern Argentina. Spanish cedar is one of the few tropical trees that is ring-porous. The heart wood varies from white to pink, the texture is usually coarse and uneven and has a non interlocking grain. The wood has a distinctive odor ( cigar boxes are made of this species). Although not high in strength, it is straight grained and rot resistant and works well. Common uses are boat building, plywood, furniture, humidors, and decorative accent work.

Availability: Moderate available, renew ability unknown

of the family Verbenaceae , Tectona grandis L also known as Kyun (Burma), Teck (French), Teca (Spanish). Is  Native to India, Burma, Thailand, Indochina, including Indonesia and is extensively cultivated in plantations within its natural range as well as in tropical areas of Africa and Latin America. Heartwood dark golden yellow, turning a dark brown with exposure, often very variable in color when freshly machined showing blotches and streaks of various shades; sapwood pale yellowish, sharply demarcated. Grain straight, sometimes wavy; texture coarse, uneven (ring porous); dull with an oily feel; scented when freshly cut. Dust may cause skin irritations. High resistance to water absorption. Easily worked with both hand and machine tools and dresses to a very smooth finish if tools are kept sharp. Commonly used in Shipbuilding, joinery, furniture, flooring, carving, cabinetwork, paneling, turnery, fixtures requiring high resistance to acids.

Availability: A tropical hardwood of limited renew ability, We purchase it as scraps from boat builders and cabinet shops to limit our environmental impact

Western red cedar (Thuja plicata) grows in the Pacific Northwest and along the Pacific coast to Alaska. The heartwood of western red cedar is reddish or pinkish brown to dull brown and the sapwood nearly white. The sapwood is narrow,. The wood is generally straight grained and has a uniform but rather coarse texture. It has very small shrinkage. This species is light in weight, moderately soft, low in strength when used as a beam or posts, and low in shock resistance. Its heartwood very resistant to decay. The timber works well with both hand tools and machine operations. Western red cedar is rated as resistant to very resistant to heartwood decay. Western red cedar is used principally for shingles, lumber, poles, posts, and piles.

Recommended use: May be used as a primary material in any paddle. Western red cedar is used in most traditional paddles on the market.

Availability: Widely available, renew ability unknown