Wood Shop Materials Research Packet
Wood Shop Materials Research Packet
Compiled January 2011
Copy #
If found, please return to Mr. Stahl
Contents:
Pages 2-28: Descriptions and Properties of wood used in the MCCPS wood shop.
Pages 29-31: Table of Wood Properties
Pages 32-33: Wood Toxicity Information
Online Information Sources:
The Wood Box -
The Wood Database -
7th Grade Science ClassPage 1
Wood Shop Materials Research Packet
Ash
Uses:
Ash is a great craft wood, but best known as the wood of choice for baseball bats. Other woods are stronger, but it has the best strength to weight ratio, and since most players do not want a bat greater than 32 oz. this becomes significant. For the same reason, it is used for tool handles, hockey sticks, and canoe paddles. Historically it was used for food bowls because it had no significant odor or taste. Curved components for chairs, snowshoes and boats capitalize on its wonderful bending properties. Really you can use it for any fine woodworking, with only your imagination as the limiting factor
The Tree:Oleaceae (olive) Family
There are about 70 species in the world, and it is the oil in the wood that is chemically similar to olive oil, that links this tree with the Olive family. There are only about 17 types of this tree found in North America and only 2 or 3 that have any commercial significance. We predominately talk about white (Fraxinus Americana) and black (Fraxinus Nigra) ash in the lumber industry. The tree is never found in pure stands, but rather is widely distributed among other species
Wood Description:
The wood is straight-grained, open pored, and hard, with no distinctive taste or odor. It is tough and yet elastic, with high shock resistance and excellent steam bending characteristics. The wood is relatively stable with little downgrade in drying. It only occasionally shows interesting figure in crotch wood. It is not considered to be a durable wood when in contact with the ground. It is susceptible to fungal and beetle attack. White ash has quite a clear white to pale yellow sapwood, with heartwood pulling more to the light to medium tone browns. Often the commercial lumber yards pull the sap out of the pile to form a more consistent white stock in the higher grades.
Weight: approximately 41lbs/cu.ft.
Finishing:
Ash finishes relatively easily and takes a beautiful stain. It is ring porous, so if you are looking for a glass like finish you must use a pore filler. It can be stained to look like oak as the grain pattern of the two woods is very similar. Ash has less chatter (ie. the little lines) between the rows of open pores, so tends to stain a little brighter than oak. You must sand carefully to eliminate cross grain scratching, particularly if you are using a dark stain.
Machining:
Ash works easily with hand and power tools, with normal wear on cutting edges. It glues well, but pre-drilling is recommended. It holds screws well. It is most known for its excellent bending characteristics. It does have a very long fibre, so splintering can be a problem when turning it on the lathe. Make sure your tools are sharp and take a finer cut. Watch the grain direction, when jointing the edges.
Bloodwood
Uses:
Bloodwood is sometimes referred to as satine or cardinal wood, for its obvious beautiful deep rose colour. With age it's colour does darken, but not significantly so it is a great wood to use in intarsia projects, pool cues, bloodwood humidors and jewelry boxes, and occasionally the jewelry that goes inside.
I've had a few customers even use this exotic bloodwood lumber for guitar bodies but usually laminated to a lighter wood on the back to keep the weight down.
The Tree: Brosimum paraense is found in the tropical jungles of South America. It grows between 80-150 ft.
Wood Description:
The wood is very dense, with a tight fine, mostly linear grain. It is relatively difficult to plane without good equipment as it can have a tendency to tear out if your blades are not sharp.
Bloodwood wood can have a tendency to warp especially if resawing thin boards. I've not found bloodwood to be the most stable wood I've used, even once it has been dried properly, so if you are thinking of resawing any material, remember not to leave it around without weighing it down, or you'll come back in the morning and it will be twisted. Once it is locked into position say in the panel of a jewelry box, you rarely have trouble.
Weight: 75 lbs. Per cubic foot.
Finishing:
Bloodwood wood is relatively easy to finishes with no oils or sap pockets that I've come across. Takes on a beautiful shine with limited effort. The grain is so tight that you can get a jewelry finish with polishing up to 1000 grit.
Machining:
Machines moderately well. Very directional when planing. It sands easily, into very fine particles, to a glass like finish, as long as you use quality sandpaper, and take the time to work down the grit sizes ... well worth the work.
As with most very dense exotic woods bloodwood is best to mill just prior to glue up to get the best possible conditions for bonding. Using a water proof PVA glue with its extra holding power is not such a bad idea .. something like a Titebond III or Helmitin 805.. both handle exactly the same as a standard wood glue but of better quality and strength for difficult woods like bloodwood.
7th Grade Science ClassPage 1
Wood Shop Materials Research Packet
Birch
Uses:
Birch's ease of use and reasonable price, have made it a great craftwood, for almost any woodworking project. It's used extensively for firewood and makes wonderful ornamental trees. It has been turned to make all the toy parts you need, tongue depressors, tooth picks, pulped for paper, and turned into high end furniture. There is little it has not been used for.
The Tree: Betula family
Birch trees grow abundantly in North America, with nine species in this family that are relatively well known, but over 50 species found around the world, including many ornamental and shrub bushes. Yellow(silver or swamp birch) and paper (sometimes referred as white or canoe) birch are the two most common trees in Northern Ontario, although sweet, river and gray birch have some commercial recognition in other parts of Canada and the United States.
"White" birch, as we know it, is not really a species but rather a combination of either paper and/or gray birch. Red Birch is not a species at all, but rather refers to the heart stock of the yellow birch. Almost all members of this family have a smooth resinous white bark, that peels, rolls or curls, in some fashion. Some types of birch bark peels up the tree, rather than the traditional "around the tree". The bark gets very thick and deeply ridged as the tree gets older. Birches are usually the first to establish in cleared land, but start to die once other trees move in and offer shade. The trees will average a height of 70' and a diameter of 2'.
Wood Description:
The appearance of the wood will vary between species, but generally, the sap wood is creamy white and the heart stock, golden brown. Paper birch is predominately sap wood, with small brown knotty hearts. The wood is mostly white but as it nears the core will show brown flame patterns, with white sap edges.. quite dramatic. Yellow birch on the other hand, tends to be a larger tree and exhibits a more consistent golden brown colour, with little creamy white sap wood. Often yellow birch shows a nice curl pattern. In commercial operations, unlike maple, it is rarely sorted for colour.
All birch has a fine and uniform texture, closed pored and no significant odor. Birch dries with a fair amount of shrinkage. It loses almost 16% of its volume going from green to dry lumber and does like to warp and twist if enough weight is not applied to the green lumber as it air dries. Once dried it is stable. It is not resistant to decay, fungal and insect attack. Spalting is very common. Of all the quality domestic hardwoods, Birch would probably be the lowest in price. This is its most redeeming feature. A beautiful wood to look at and work with, and sold at a reasonable price.
Weight: 40-45lbs/cu.ft., white birch slightly lighter than yellow birch.
Finishing:
Birch stains and finishes easily, due to its closed pored structure. In fact often it is used as a substitute for Maple. Birch is significantly easier to stain, will give you an almost identical stained finish, but with much less grief, especially if you are trying for a relatively dark color.
Machining:
In all categories, birch exhibits good machining properties. It planes and sands to a smooth finish. It cuts and drills with limited difficulty although I would always predrill for nailing. Birch does hold nails and screws relatively well and glues up easily. Where curly or wild grain is apparent, you may have to be careful. Taking a shallower cut and using a cutting angle of 15 degrees will usually solve the problem. Look at the grain direction to determine the right feed direction when jointing. It turns with ease, but will show cross grain scratching so sand meticulously before staining.
Cannarywood
Botanical Name Liriodendron Tulipifera
Other Names Tulip Poplar, Popple, Saddletree, Whitewood (UK), Canary Whitewood, Tulip Tree (US)
Wood Description:
Color/Appearance: Heartwood color can vary a fair amount, from a pale yellow-orange to darker reddish brown, usually with darker streaks throughout. The color tends to darken with age: see the article Preventing Color Changes in Exotic Woods for more information.
Grain/Pore: Has a medium texture and small pores. The grain is typically straight, but can be irregular or wild on some pieces.
Mechanical Properties
This medium density wood has low bending and resistance to shock loads, low stiffness and medium crushing strength. It also has a medium steam bending classification.
Weight: 50 lbs/ft3
Working Properties
It is easy to work with hand and power tools and can be planed to a very smooth finish. Nailed, screwed and glued joints hold perfectly, and it can be stained, polished or painted and holds hard enamels.
Durability
Rated as very durable in regard to decay resistance, as well as being resistant to termite and marine borer attack.
Uses
Pattern making, carving, cabinetmaking, interior fittings, light construction, interior trim for boats, toys, doors. It is also used for plywood and core stock. Selected logs are sliced for veneers.
Comments
Not to be confused with the softwood known as "Whitewood".
7th Grade Science ClassPage 1
Wood Shop Materials Research Packet
Jatoba/Brazillian Cherry
Uses
Jatoba wood, is often used in flooring but also ideal for stair treads, athletic equipment, tool handles, railroad ties, gear cogs and wheel rims. Can also be used for carpentry, cabinet making and general woodworking joinery. I have sold it to clients as a cheaper substitute for teak, when it is the appearance you are looking for and don't necessarily need the oily, rot resistant characteristics of teak. Jatoba and teak can look very similar.
The Tree:
Leguminosae Family Jatoba (Hymenaea courbaril) grows to an average height of 120 feet with diameters of 2-4 feet. Jatoba is often referred to as Brazilian cherry although it is not a cherry wood, and has been called Locust or Courbaril in different areas of South America. It grows in most of the South American islands as well as Mexico, Brazil and Peru.
Wood Description:
The wood is an attractive burgundy, deep red, or orange tone, and some of it can even have dark black stripes highlighting a strong visible grain pattern. It can exhibit quite a large colour variation from one board to the next.
The heartwood varies in colour from a salmon red to an orange brown when it is freshly cut which darkens to a red brown when seasoned. The sapwood can be wide and is much lighter in colour - either white or pink and sometimes gray and does not darken to the deep red-orange tones common with the heart wood. It is not as porous as mahogany but harder and denser.
Brazilian wood has a natural luster, with a medium to coarse texture. It has no obvious taste or odor. The heartwood is rated as only moderately resistance to attack by fungi and marine borers. Although the books might suggest the wood is relatively stable once it has been dried properly, my experience might suggest that every so often you'll get a few pieces of wood that really don't want to behave... they don't like to be glued and if they can twist, they will.. it is not one of the easiest woods I have used, but the gorgeous colours do warrant an extra bit of effort.
Weight: 56 lbs. per cubic foot.
Finishing: Jatoba sands and finishes easily. Polishing can create a wonderful luster. It stains well.
Machining:
Can be hard to work with, having severe blunting effect on tools. It is moderately difficulty to saw and machine because of the wood's high density and toughness. Experts recommend a reduced cutting angle of 20 degrees, and the use of carbide cutters as much as possible. The wood's interlocked grain also causes some difficulty in planing. Brazilian Cherry wood nails badly and must be pre-bored before nailing. The screw-holding ability is considered good. Although jatoba turns well, the grain can be somewhat powerful and require sharp tools to avoid tearout.
7th Grade Science ClassPage 1
Wood Shop Materials Research Packet
Cherry
Uses:
In cabinetmaking, cherry is rated one of the favorites because of its beauty and versatility� it has warmth, personality and charm. As a craftwood it cuts,stains and sands beautifully, which makes it a hobby wood of choice.
American black cherry is widely used for paneling and as a veneer, burial caskets and other specialty items such as gunstocks, tobacco pipes, musical instruments, turnery, carvings, etc. It is only moderately durable for outdoor projects. Cherry wood is my personal favorite, of all the domestic wood species.
The Tree: Prunus Serotina Family
Black cherry stands alone for its commercial value as a lumber wood. Other cherry trees most often function as decorative trees or fruit bearers. Black cherry is characterized by late maturing fruit and is distinct from the other cherries because it has dark bark with irregular scales that peel off easily and a light to dark reddish brown heartwood.
The fruit of this tree is small and purple coloured with a bitter taste and is used to flavour jelly and beverages. At one point it was used to make a very potent liquor. American colonists used the bark as a drug to treat bronchitis and cherry stalks were used to make tonics. Its grows predominately in east-central North America, with smaller shorter trees more common in southern eastern Canada.
Wood Description:
Cherry has a pale yellowish sapwood and a darker heartwood. The wood's colour deepens to its characteristic reddish brown, almost mahogany-like colour when exposed to the sun. The sapwood never darkens to the same colour of the heartwood. Cherry often shows a waving curly figure when finished. Heartwood can have dark spots or fine black lines that are actually gum pockets, that pose added challenges in finishing. Often maple is stained to look like cherry in furniture components that require a more dense wood.
Weight: 35 lbs. Per cubic foot.
Finishing:
The grain pattern welcomes a full range of medium to dark finishes and bleaching treatments. The best way to achieve a uniform deep red colour is to let mother nature do her work rather than attempt staining. If you have to replace a board, remember in time, the sunlight will darken all cherry, even if it doesn't look like it matches in the beginning. It has been suggested by some of my customers that aniline dyes work particularly well on cherry, but I have no experience in this area. Scratches show up easily on cherry so pay attention to your sanding preparation.
Machining:
Wood is uniform in texture and machines well with normal wear on your tools. Its tight fine grain routes well but does have a tendency to burn, so stick with carbide bits and don't stop the router on the wood. Watch the feed direction when jointing, particularly on boards that show a nice curl. Likewise when thickness planing, keep your passes to less that a 1/16" and always pay attention to the feed direction. If tear out occurs, you can always reverse the direction. Obviously you don't want to be experimenting on the last pass. Cherry turns beautifully, but you must sand with the grain to eliminate the cross grain marks.