- Wood species
Other Versions
Spanish
Information on tree species and their uses. March 20, 2001
Oak
Question
How can you identify red oak lumber from white oak lumber?
Forum Responses
A method commonly used by lumber inspectors when grading freshly sawn red and white is to look closely at the ray length. The white oak rays are often over 1.5 inches, while the red oaks are around .75 inches. Once the lumber has started to dry a bit, the ray length stands out better.
Another sure way is to use a mixture of 10% sodium nitrite (by weight) and tap water. Once applied, the red oak will turn red or orange, while the white oak will turn very dark.
There are some white oaks that do not have tyloses--chestnut oak, for example. There are also times when red oak will have tyloses (traumatic tylosis). Traumatic tyloses result when the tree is injured. I think that small forest fires also cause them.
So, do not use tyloses as a reliable indicator. Instead, use the ray length or sodium nitrite. With 10x magnification, it is also possible to separate the two.
Color is a very poor indicator, as some white oak is much redder than red oak and some red oak is darker than white oak.
Gene Wengert, forum technical advisor
10x magnification works good for me, using Bruce Hoadley's book as a guide.
Does anyone know what the chemical difference is in these oaks that causes the sodium nitrite reaction?
The theory is that the chemical that the test responds to is some precursor of certain tannin compounds. A technical paper about this in the Forest Products Journal about 10 years ago proposed a possible acid precursor that was the key, but I do not remember the acid's name.
Gene Wengert, forum technical advisor
Question
In my area we have what folks call pin oaks, post oaks, red oaks, white oaks and many others. My understanding is that there are only two real types of oaks--red and white. Which of theses fall into which group? Which ones make quality lumber?
Forum Responses
The red oaks are usually easier to identify than the white oaks. The trouble with white oaks is that there are so many different species and some have limited use. Don't buy any burr, swamp or mossy cup oak unless you can buy it at utility grade price. Many mills and veneer buyers have bought millions of dollars worth of these grade inferior white oaks, only to find that they weren't the real thing.
I think the best northern red oak comes from the eastern Great Lakes region, such as the state of New York or the province of Ontario. Red oak is also subject to mineral deposits, which lower the grade if grown in very rocky areas. It's hard to identify the white oaks, unless you can actually see the tree.
What are the reasons not to use burr oak?
It's been my experience that the color of the wood has a greenish cast (not the same as the black walnut). This is after it has cured.
Except for white oak grown in a very wet site, all the other oaks are fine to use. However, you need to slow down the drying of any oak (red or white) with wide ring spacing--over 1/4" wide--as these oaks tend to check much easier than the other oaks. But, if you slow down the drying, they are just fine. The comment that a certain species is not good is because the drying conditions were not changed to accommodate the needs of that species.
Of course, any oak infected with bacteria (foul odor, ring shake) will not dry well no matter what you do.
There was a good article about oaks in Sawmill and Woodlot Management magazine recently. The book I wrote, Drying Oak Lumber (Forestry Dept, U of Wisc-Madison, 608-262-9975), has a section about them.
There are 80 species of oak in North America. Here are the main ones:
Red Oak Group
Black oak Quercus velutina
Blackjack oak Q. marilandica
Cherrybark oak Q. falcata
Laurel oak Q. laurifolia
Northern pin oak Q. ellipsoidalis
Northern red oak Q. rubra
Nuttall oak Q. nuttallii
Pin oak Q. palustris
Scarlet oak Q. coccinea
Shumard oak Q. shumardii
Southern red oak Q. falcata
Water oak Q. nigra
Willow oak Q. phellos
White Oak Group
Bur oak Q. macrocarpa
Chestnut oak Q. primus
Chinkapin oak Q. muehlenbergii
Overcup oak Q. lyrata
Post oak Q. stellata
Swamp chestnut oak Q. michanxii
Swamp white oak Q. bicolor
White oak Q. alba
Gene Wengert, forum technical advisor
I find that the biggest problem with some white oaks is not being able to get any high grade boards out of them. They usually contain lots of pin knots. The white oaks also require special drying considerations, due to the nature of the blockage in their vascular structure. Stave oak (white oak) is particularly desirable for this reason, since it will not draw the contents from the whiskey barrels. Burr oak will usually contain many internal defects, such as large and small knots with an irregular grain, however this could be just region specific. Trees of any kind can be used for boards; it's just grade and application that needs to be considered. The white oaks are particularly impervious to rot and make great timbers for log structures, although heavy.
In grading white oak, sometimes we use the grading rule WHND, which allows pin knots.
(Worm Holes No Defect = WHND)
Gene Wengert, forum technical advisor
Which category does the live oak fit into and how hard is it to dry?
Live oak is a separate category. It is extremely difficult to dry. It was often not dried at all. It is Quercus virginiana. It was used in ship building (especially in areas that might get hit from a cannonball, as the wood is extremely tough and hard).
Gene Wengert, forum technical advisor
Post and white oak are very close and sell as the same, though post has more small knots. But last week I sold over 100 board feet of FAS post oak. If it is white oak (see Gene's list, light bark), okay in the ground. If red oak (dark bark), never put it down. Grandpa's saying. Black oak and blackjack are only fit for firewood. The leaves of the same type of oak may be somewhat different and it can be hard to tell oaks apart. There are many good books--get one and take a walk in the woods.
In my area, black oaks are comparable in quality to northern red oak. A red oak usually yields a little more FAS than black oak, and the #1 C holds up a little deeper into the cant. Most of the red oak lumber we produce comes from black oak trees.
Gene, are willow oak, peach oak and shingle oak all regional names for the same tree, an oak with a single lobed leaf? We have lots of them. If they grow near red or black oaks, they make decent red oak lumber. If we cut them in an area where pin oaks grow (usually a little wetter ground), they have lots of pin knots just like the pin oaks.
Peach and willow are the same, commonly, but I do not see shingle oak on my list.
Black oak grows on poorer sites better than some other oaks. As a result, some people are quite negative about black oak, but, when it is on a good site, it is a good wood. The sawing yield tables do show a reduction in yield for black oak, unless WHND.
Gene Wengert, forum technical advisor
Alder
Question
Would somebody tell me a little bit about alder?
Forum Responses
I cut western red alder and find it is a very good wood for furniture, windowsills, etc. It is not very decay resistant and not extremely hard. It has a ray fleck to it if QS and an open grain texture, very pretty to me. Milling it is like killing a snake--it never stops moving and it is hard to get straight boards. It is best to keep turning the log during milling to avoid this. If you air dry it, you will have no control over the color and will get a mixed load of stained and clear boards, mostly stained. To beat this you must kiln dry it.
I have been told it only grows within 150 miles of salt water, so it will only be a coastal wood. It is one of the least expensive hardwoods around here (western Washington State). It is much softer than cherry, and is fairly plain in grain and color.
I cut alder almost exclusively. One of the reasons for the "snakiness" of the wood is that alder trees almost never grow straight, especially in a forest. A very fast-growing tree, they will lean, twist and turn to reach the sunlight in dense woods. Consequently, there is a lot of reaction-type wood. I've only seen alder logs cut at 8' and 10' lengths--it's hard to find a straight log longer than that!
When you first buck a tree into logs, the wood is nearly white. Within hours, sometimes minutes, the wood changes to a reddish color. When you saw your logs, the boards need to be put in the kiln immediately to control color.
I like alder logging and sawing a lot. The trees only live for about 60 years before they begin to die, and can be harvested as early as 25 years, so it's a wonderful, renewable resource.
You might find alder in the interior. It grows around here (central Kootenay, nine-hour drive to the big pond), along with birch and cedar in the moist creek draws. Like the Pacific Yew around here, it usually doesn't achieve much size, but I've sawn some 12-14" logs.
There are five types of alder--red, mountain, sitka, white and thinleaf.
Question
How does red alder machine? Does it tear out like maple? Is it a good, stable furniture wood?
Forum Responses
Alder machines very well. It doesn't tear out like maple. It is a soft hardwood, a lot like poplar. I believe it is a very dimensionally stable wood. It is called "poor man's cherry" because it has similar grain and, with the right stain, looks similar to cherry. It also takes stain exceptionally well and can look like dark mahogany.
It matches well with birch. I used it for facing, drawer fronts and molding on a dresser in which I used birch plywood. I used a dark walnut
Minwax stain.
I just completed a kitchen in alder. It machined very well, except for planing. I had to take small cuts or it would peel. Using a horizontal drum sander gave better results. The only other problem I had was some fuzziness when routing, but it sands off easily.
I made a replacement body for a Fender Stratocaster out of alder. I loved working with it. It machined excellently. It is not very easy to come across in Kentucky or I would use more of it.
We have done about thirty kitchens and many furniture pieces in the past three years with alder. It is great to work with. It does tend to peel when planing. I've found that planer knives with some mileage reduce the peeling greatly. Waste can sometimes be high due to twist or bow as it comes off the table saw. I think this is due in part to too fast kiln drying (or because it's nearly a weed). Alder is rather inexpensive here in the northwest, so it makes up for the occasional boat keel lumber. If clear finishing, red birch ply is your match. Caution: alder oils very blotchy.
Hemlock
Question
I'm looking for information on hemlock, such as uses, drying and workability.
Forum Responses
In years past, hemlock was a very important species, and was used for windows, molding, construction timber, and so on. One serious problem was that older logs tend to be very shaky--that is, there are separations parallel to the rings. This shake gets worse in drying. So, old logs seldom produce much good lumber. Plus, old logs with bacterial shake would not float in water, so transportation was a problem. They called them sinker logs.
With all the problems and with a supply of alternative species (especially white pine), the use of hemlock declined to close to zero. Today, the markets for Eastern hemlock are very small and not consistent. It is a good wood, if without shake.
It is low weight (density) and as a result, has low strength and stiffness compared to Douglas fir or Southern yellow pine. But it machines well, glues well, and has a nice grain pattern.
Gene Wengert, forum technical advisor
Hemlock makes excellent floor joists, studs and rafters as well as barn siding and timbers, if it is sound wood. Some people use it to grow mushrooms.
In Nova Scotia, Eastern hemlock has been used for railroad ties (creosote treated), wharves and boardwalks (pressure treated). I've cut lumber for outside steps and decks for folks who demand less chemicals. Despite what the academics say, I feel it stands up fairly well outdoors. It splits easily, so it has to be pre-drilled.
I prefer to use it at 1.5" thickness, but some order 1". It is reasonably strong. Contractors use it around here for staging planks at 2". They strap the ends with steel strapping and warn their employees not to toss them off the staging. The branches, which seem to be fairly dense, make nice firewood. The hemlock is very heavy when green, but dries to be quite light. I heard that the material is used for exterior jambs, for its propensity not to warp. I like hemlock.
Hemlock is inexpensive here. I cut staging planks and beams, but my pallet maker customer also uses 4/4 hemlock for pallet deck boards. Most of my stickers are hemlock, as it is tough and doesn't stain.
When hemlock burns, it snaps and sparks. The shake and splinters make it a hard wood to deal with, but I live in a 200 year old house that is built mostly of hemlock.
Can hemlock be used for log cabins?
It is great for underwater use, such as a bed for rock abutments or submerged structures. I don't see why it couldn't be used for log cabins.
Larger hemlocks have shake, smell bad, and weigh quite a bit.
Gene Wengert, forum technical advisor
I have heard rumors that hemlock contains carcinogens, at least as a fine sawdust.
Question
What are some uses for hemlock? I have about 100 cords, in the UP of Michigan.
Forum Responses
I bought some 2x8x8 and re-sawed most of it into 2x4 and 1x8 for sheds. Dries nice and light but a lot will have shake. The bigger the planks, the less the problem with shake.
It makes good scaffold planks and I use it for 2 by stock. I also make all my stickers out of the trimmings.
Construction lumber 2x, 3x, 4x, etc.
Barn siding
Picket fence boards
Flower boxes (put liner inside)
Pallets
Crates
Stickers for lumber
When you mention cords, are you thinking of small diameter? Many of the uses mentioned above are for larger trees. Small diameter logs will likely have many knots, so construction lumber is not possible. Plus, small trees tend to have compression wood. The warping of small logs with the juvenile wood is also a problem, so the uses such as siding, flower boxes, fence boards, and other items where straightness (both in manufacturing and in use) is required would not be good. Then add in the bacterial problem (which causes the shake mentioned) and you have pretty poor wood. That is why it is very hard to find Eastern hemlock in the marketplace and the prices are very low. (I think maybe one of the replies above was for western hemlock or another may not have the experience of what the Lake States hemlock resource is like, quality-wise.)
Eastern hemlock is not a scaffolding wood, as the strength is not there and the clearness required for such stock is not usually present. Western hemlock is more often a prime species.
Gene Wengert, forum technical advisor
Eastern hemlock gets a bad rap. People here use it as a non-chemical solution instead of p/t lumber for decks. Old timers used it around exterior doorjambs. When I started building my house I purchased 4-2"x10"x10' E hemlock planks. After using them for masonry purposes and other uses, I had occasion to be up on someone else's dressed 2"x12" staging. It bent so much I was sure it was going to break. I've since seen contractors use the plank, but with 1/2" metal bands tied around the wide portion at each end. They split easily but are strong if you can keep them together. Nail holes should be pre-drilled if close to an edge.
I too have seen 8"-10" diameter logs converted to timbers for timber frame homes and they do just fine.
I have a hemlock deck, which is 12 years old and is more sound than a few of the PT boards I used on another.
Small hemlock logs can be the most beautiful stuff in the world.
Are you saying that you have some pressure treated lumber that is decaying? If so, then it must not have been properly treated. Perhaps it was "treated to refusal", which means that only the outside fibers got any chemical. It certainly was not treated according to any standard and then certified. Some "cheap" lumberyards sell material that is green colored, but has no decay resistance. In fact, the State of GA had this experience in many 6x6 posts. They did not specify that the treatment had to be certified by a recognized agency or member of the AWPB/AWPI. Look for the label on each piece of inked stamp indicating the treatment level and certifying agency.
Regarding strength, we base our design values on the 5% weakest piece, not the 95% stronger pieces. So, you can certainly find a few strong pieces. However, if you think that hemlock is strong, you are not aware of the many legal cases that have resulted because hemlock structural members, esp. scaffolding and ladders, broke and injured someone. Strength is a function of grain angle, density, and several other factors. Unfortunately, E. hemlock is poor in many of these factors. You need to have a broad outlook in this matter, and not just a few pieces here or there, or just one deck.
E. hemlock has been used for many items over the years and there were some good trees and good wood. Some of the stories about decay resistance are based on old growth wood; oftentimes the newer or secondary growth has much less natural resistance. This is true for many species.
Gene Wengert, forum technical advisor
I have purchased PT lumber that looks like junk and is not as structurally sound as when installed. I am against PT lumber! Copper Chromated Arsenate (spelling could be off) is great for picnic tables, benches, chairs, sandboxes, vegetable planters and pool decks, right? NO.
I have had poisonous splinters from PT wood, and others I know have had all sorts of rashes and even blurring of vision from airborne PT sawdust.
Also, I guess all the 130-180 year-old barns around here built of E hemlock are not safe to stand in during a windstorm.
You can include lots of houses, bridges, etc. in Eastern Canada. I was just surprised at the difference in the sturdiness of the 2"x10" rough plank and a dressed 2"x12" plank that was probably spruce. I agree with Gene that when you get near the top end of a tree, large knots, etc., quality suffers. I built a 15' span bridge 13.5' wide using 3" E. hemlock decking last year. I used my Logosol. The owner was very pleased. Others do not like P/T. Again, I found that if you can keep it together, it makes strong lumber.
If one is in a rural area where one does not have to worry about OSHA or an insurance company inspecting scaffold planks, you may get away with it. I have seen jobs put on hold because of somebody saying he has used specie "A" for years for scaffold plank, and the safety inspector shut them down. Why risk your life with unsafe scaffold planks?
Just ask someone who has fallen from 10 or 20 feet.
Hemlock is used around here for pallet stock, but aspen is usually a better choice, even for pallets.
Sweetgum
Question
I've been told by many locals that sweetgum is a trash tree, but I've read that sweetgum is second only to oak in hardwood production. Can anyone tell me more about sweetgum?
Forum Responses
It dries funny. But it has a spiral interlocked grain, and is rather difficult to split by hand, so I think it would make a good hidden wood in furniture construction (if it will dry straight for you). I have seen the heartwood in different colors, and sometimes a purple, kind of pretty.
If you want to see some really pretty panels then make them out of sweetgum. The contrast of dark heart wood and creamy sapwood is really pretty and lends itself to book matching. The secret to using it is to get it dry and to take time with drying so that it doesn't cup too bad. I have been told that it is harder to dry thick wood but have found that when I cut my "hard to dry" hardwoods 5/4, they are easier to manage and I get better results than if I cut them 4/4.
Bowl turners like sweetgum, too. It not only makes a pretty bowl, but doesn't split (locked grain) like oak or some other straighter grained woods.
Beetles like it, though, so keep an eye on your drying stack.
Back in my firewood selling days, sweetgum was a bear to split. Many times, it would split across grain before it would split with the grain. From this experience, I would be hesitant to use it in a structural capacity unless it was a bit oversized. But, it does make a beautiful turned plate!
Gum is my favorite wood. I have run out of gum lumber and I am quite sad :-(
It dries with a lot of warp due to the grain of the tree not being straight up and down, but being spiraled up the tree (like a barber pole, you old folks). To make it worse, the spiral reverses direction every year or so. Because the fibers are angled, their normal shrinkage in width will actually show up as a little shrinkage lengthwise,too.
Gum is easy to work (gluing, fastening, and machining), is fairly stable, but is strong and hard enough for most uses. It can be finished to look like walnut, cherry, mahogany, etc. It often has enough character of its own that it looks good with a clear finish! The warp in drying has scared many people away from this species, yet it was widely used in the past.
Gene Wengert, forum technical advisor
We cut a lot of sweet gum for roof lathing. It is nailed up green, so when it dries and shrinks, it will hold nails like no other species.
I have a fair amount of black gum, with the same bad rap for shrinking and twisting. Creamy to olive sapwood.
Black gum is really black tupelo and is not related directly to sweetgum (sap gum or red gum).
Gene Wengert, forum technical advisor
Question
How do you tell the difference between soft maple and hard maple? The heartwood of the tree I have has a very distinct dark coloration. Should this concern me? Is it true that soft maple has the ability to produce curly and birdseye? Does soft maple have many of the same applications as hard maple?
Forum Responses
Soft maple is lighter and softer than hard maple. The best way to tell the difference is to use 10X magnification and look at the ray size--hard maple has two distinctly different ray sizes. Many wood ID texts will have pictures to show this difference.
The brown in maple is usually considered a defect for most uses. Premiums are paid for the white sapwood.
Soft maple seldom has curly and bird's eye.
Soft maple is inferior in many situations to hard maple. It also has more color variation than hard maple due to the angle that it is viewed at.
Gene Wengert, forum technical advisor
I have found that most soft maple has a heart that is almost grey colour, while the hard maple heart is more brownish red. Soft maple also seems to have a softer bark that the hard maple.
The inner bark of soft maple is reddish, where the inner bark of hard or sugar maple is golden. Soft maple often exhibits a spiral grain pattern (in the Northeast). Outer bark pattern is different also--hard maple is often rougher in mature trees.
Soft maple has a more scaly, thin bark, while hard maple has a tougher, raised bark. The sapwood of soft maple is usually very white and the hearts are often wormy as well. Soft maple will usually grow in a wetter site than hard maple, and will usually display multiple trunks due to sucker growth. Both woods are used interchangeably for utility grade. The heart centres of both species are better used as cants for stacking your lumber.
Red elm
Question
I live in southeast Nebraska and several times I have been given red elm. I would like to know more about this wood. The wood has all been dead for some time, no bark left. It works like the local green ash and they say it is very good firewood.
Forum Responses
Red elm tops make great fire wood. I cut a couple of tops up for that purpose every year. The saw logs are desired by local sawmills here in north Iowa. They aren't as abundant as they once were because of the Dutch Elm disease, but quality trees still do exist.
I have used red elm several times for picture frames and such, and I think it is great. Works fairly well and finishes nice. It does twist some when drying. Dry it slow. You don't see a whole lot of it--that is another reason why I like it.
Has anyone milled dead standing red elm? Does it mill easily or is it hard after drying? I just milled some very dry oak and found it to be very hard to do.
I milled some red elm that had been standing dead for several years (no bark). It cut easy, no wandering of the blade. The sapwood was poor and there were surface cracks in the log. Large sound boards were tough to get, but lots of nice smaller stuff. Planes nice. You are right about dry oak.
I guess from what I read here is that red elm is American elm. The American elm I have cut will twist a lot if there is a good size knot in your 4/4. I have used American elm in some projects--works great and looks good. We get a lot of it here in Denver. A good hardwood.
Red elm is Ulmus rubra, while American elm is Ulmus americana. Red elm is usually called slippery elm. These two species make up a group of elms called soft elms.
The other group of elms are the hard elms and include rock (most common), winged, cedar and September elms.
Soft elms are known for their warping during drying. 12" sticker spacing is advised along with top weights, low RH and not too hot.
Gene Wengert, forum technical advisor
We have a lot of red elm in Oklahoma, and I never turn it down. It is most often just given to me if I will haul it off. But I will not take any if it has been dead more than two years. In this area it gets doughty in year three. It makes pretty woodwork and molding. I did my den with it and everyone always asks what that pretty wood is. They don't believe it is red elm.
What kind of elm is white elm? I heard that white elm sells high in the market.
White elm is rock elm, although rarely it has been used for American elm.
Gene Wengert, forum technical advisor
Red elm is a great wood, one of my favorite furniture woods. I logged and sawed about a dozen trees or so that had been standing for 20 years - no rot, decay, or any other flaws had yet occurred. It milled well and was beautiful. It is often used for steam bending, boats, barrels, etc. However, my favorite is furniture. The only caution is that it tends to have a fine, hairy layer of grain that you can never really get off no matter how fine you sand it. Just finish over it, sand after the first coat of finish, and you'll be fine. My advice - take all you can get, no matter how old. It's becoming more rare as we deplete the last standing soldiers who died in the Dutch Elm disease war.
I think red elm is hard to cut. The first cuts are the worst. It is real stringy under the bark, and this builds up on the blade tips, so when you hit a knot the blade goes crazy. Once it is 4 sided, it is not too bad to cut, but the logs I cut sure showed a lot of stress no matter which side of the cant I saw.
Blue beech
Question
We have some 6" diameter blue beech; it's very sound wood, no rot. What is it used for, other than wooden mallets?
Forum Responses
I use it for Gluts and mauls but its old typical uses were things like weaving shuttles that really took a beating. I don't know of any commercial use for it today, but the old timer's stories about it are pretty interesting. The small diameter sticks make an interesting hiking stick.
Blue beech is a small tree with hard wood and a trunk that looks like a muscled arm with slick bark. It grows in hardwood swamps along areas of "wet weather creeks" in my area (N. Fla, S. Ga.).
From the original questioner:
I had no idea it was found that far south-- I am in eastern Ontario--upper Ottawa Valley. Here we usually only find 2 or 3" stuff; maybe 6" isn't so impressive after all!
The range looks to be about 100 miles into Fla. and the entire eastern half of the continent. Most of the trees on my place are in the 4-6 inch range and are 2-5 stems. I'll bet the wood would be pretty if turned into spindle type stuff. If you know anybody that turns between centers, it may make an interesting experiment. I know that the pieces I have played with polish real good. The stands make a pretty miniature forest and I like to sit in it and watch the squirrels. I had no idea that the life of the tree was 100 years. Your question has given me a reason to have a whole new outlook on them. Maybe 6" is more impressive than you think.
Carpinus caroliniana. I understand that the wood is prized for mechanical pieces in pianos.
Blue beech belongs to the birch family and is known as ironwood or musclewood or hophornbeam, unlike American hornbeam or ironwood of the same family. Blue beech is very tough but not impervious to rot. It is known as musclewood because of the way it looks once the bark is stripped. It bends very well once steamed.
Soapberry
Question
Does anyone have experience with soapberry wood? I have a chance to get a pretty good size trunk, and wonder if it's worth cutting up into lumber for projects.
Forum Responses
Latin: Sapindus saponaria.
If I'm not mistaken, soapberry is the same thing we call chinaberry around here. I have milled some and think it is a pretty wood. It tends to split when dry. Nice pink-to-red color. Looks a little like oak. Easy to cut.
Pear wood
Question
To season a pear log, do I cut it into planks, dry it bark on and seal the ends? Is this wood even worth the time and trouble and space it will take up?
Forum Responses
It's definitely worth the time and trouble. Seal the ends as soon as possible. I would take off the bark, but that's just me. Sticker it well and weight it down--pear twists and warps like crazy if you don't. It's beautiful stuff and really nice for turning. Spalted pear is some of the most beautiful wood I have ever seen.
Pear wood is used for making flute type instruments. It gives a mellow sound and is attractive. I have some apple I am saving for this purpose.
Question
We are having problems telling the difference between redwood and Douglas fir. We have a pile of dimensioned 1x4 and it contains both redwood and fir. There are pieces that are obviously redwood and some that are obviously fir, but it's really hard to tell on about half the boards. We need to be sure since we are going to use the wood outdoors.
Forum Responses
A 10x magnifying glass and a copy of Bruce Hoadley's book "Identifying Wood" should do the trick.
Is the wood rough sawn? Getting a smooth surface might make things a bit clearer. Scraping the end grain of a board until you can plainly see the growth rings might help, too.
The weight of these two species is tremendously different. You shouldn't have difficulty sorting them. Douglas fir is about .6 pounds per BF heavier, so even a 2x4x8' would be 2 pounds heavier. Will this work?
Gene Wengert, forum technical advisor
From the original questioner:
The weight idea should work, but these are 1x4s. They are actually finished to 3/4 x 3.5 x 9' long. That's less then 2 bd ft in each piece. So the Douglas fir pieces weigh about 1 pound more then the redwood pieces. And that is spaced out over 9 feet. The color of the whole pile has a reddish tone to it. That's how they got mixed up in the first place. There are 400 pieces in all.
Can we look at the end grain? Will there be a significant difference there?
A sharp fingernail might tell you. Douglas fir should rip your nail off and the redwood will be softer.
It's a good question. Here in California, there are dozens of people who profess that their houses are framed in redwood. Termites won't eat it, they say. There are probably a few, but I have yet to see a house built out of redwood. Another thing I have heard is that people have found old growth redwood "and it's so hard that you can't drive a nail into it". Now, redwood is lighter, but is seems that it is always a whole lot softer.
Anyone know how to tell the difference between red fir (Abies magnifica) and Doug fir? My neighbor, who seems to know what he is talking about, says all the turn-of-the-century houses around here are made from red fir and it sure looks like Doug fir to me.
I assume that by "red fir" they mean Pacific silver fir (Abies amabilis). This is 20% lighter than Douglas fir, and so strength properties are lower--Douglas fir has an MOR of 7700, while Pacific silver fir is 6400 psi. However, Douglas fir is sometimes called red fir, so maybe the framing is actually Douglas fir.
You can separate the true firs from Douglas fir by looking at the wood end grain under 10x magnification. Douglas fir has resin canals (frequent but not every ring), while the firs do not have resin canals.
Gene Wengert, forum technical advisor
About the redwood vs. fir, besides the weight difference--no matter how old, some Doug fir will weigh at the lightest, slightly heavier than redwood. However, no matter what, if the redwood is all heart, it will be dark red when you shave a big sliver off a corner--fir will be yellow to light brown--the most you get is a hint of red or pink. You can tell by nose if you care to cut--the fir will smell 'pitchy' and resinous and the redwood won't--it has no resin.
By the way, houses framed in redwood in California are very rare after about 1890. Usually only cottages in the redwood country, where it was cheap. People think it's fir because it can sometimes be pink-brown if it is old enough. Redwood has always been poor framing lumber, very low bending strength--it just breaks under light loads. Fir was usually cheaper anyway, after 1880--they brought it down the coast from Oregon and Washington in 'coasters', two-masted schooners and brigs that just hauled lumber. But it's always been true--redwood is immune to plant virus, dry rot, mold, insect damage, water to a fair extent and fire to some extent--it burns slowly for a softwood-lack of resin and pitch.
From the original questioner:
The pile of wood is very old and dirty, so that's also making it hard to tell the difference. We are using the weight of the pieces, their feel (if soft or hard) and a knife to slice a corner off to get to the fresh wood underneath the dust. This seems to be working. If we have any doubts, we assume it's fir, so we don't use this outside.
We also have discovered a lot of redwood that is finger jointed. We will not use this outside, since the glue joint probably will not hold up. What did they use this for?
Finger-jointed redwood has been used in the past for siding and trim, primarily where it would be painted, and where the trim was exterior and the use considered best for redwood because of its rot resist qualities--usually milled siding. Milled to contour--clamshell, t&g, triple roll, 1/2 round or cove end 1x6, 1x8, etc. Redwood machines and mills with less bust-up because it's softer. The finger joint is because as redwood uppers have become scarce, lower grades with sapwood end up at the mill, the sapwood lopped off, and finger joints get the lengths sold.
Eucalyptus
Question
In California, we have numerous species of eucalyptus. I have worked with different species with different success rates. Has anyone experimented with this difficult wood?
Forum Responses
There has been some work with euclyptus in California, but more in South America, especially Chile, and in Australia and New Zealand. Try the extension service. Generally, if you treat it like white oak, you'll be okay.
We're in California and really stay away from the stuff. The only thing I know it to be suitable for is mallet heads. Australians ought to have the word on it, though--all of California's eucalyptus came from there, according to the history books. There are some Austrualian cabinetmakers on the web that show eucalyptus stuff, but it doen't look at all like the California wood.
My understanding of eucalyptus is that it was introduced to California, but the climate is wrong, so it grows too fast to be any good.
What you heard about Eucalyptus and stated above is not true.
Gene Wengert, forum technical advisor
There are hundreds of eucalyptus species. What kind are you talking about? They all behave differently and have traditional uses. River red, snow, stringy bark, yellow box, red box. It's a very long list.
From the original questioner:
I have tried bluegum, red iron bark and camaldulensis (sp?). The ironbark seemed to be the best, but the question is about any and all that have been tried in California. I am wondering if there are any that mill well so I can try those.
My favourite has to be river red gum. It works a lot like Euopean oak. Ironbark, now that's just asking for trouble. It's nice to cut but a bastard to work. I hear bluegum is nice, kinda average--haven't had the pleasure myself. Snowgum is interesting but difficult to get a straight bit.
I don't know why everyone is frightened when you mention the name eucalyptus. We dry and process t&g flooring from bluegum, ironbark, spottedgum and blackbutt, to name a few. You will not find a more durable and hardwearing specie than the good old ozzie hardwood.
I agree--can't think of a rastier, hard, durable, almost unworkable wood for floors--must be bombproof. What a good idea for the stuff.
From the original questioner:
Flooring would work well, but are people interested in buying eucalyptus? I was told of a man who milled bluegum for truck beds. He bolted them down green and they worked well.
For flooring, it just depends on what it looks like. Sounds like eucalyptus could be graded for good color and grain like any floor. Certainly some of the cabinets and furniture I've seen done by Aussies shows this. After all, if Chinese bamboo, properly graded and machined into flooring by Netherlanders, is the rage in parts of California, eucalyptus might just be a real meatball for somebody. Particularly for a tree that is considered by many to be a non-native weed, and that people pay sawyers to remove.
The comment below was added after this Forum discussion was archived as a Knowledge Base article (add your comment).
Comment from contributor A:
The question about eucalyptus timber is impossible to answer. As a previous reply stated, there are hundreds of different eucalyptus species with vastly different characteristics. Also, the same tree grown in different climatic conditions can produce different timber. The only way to deal with eucalypts is to know their botanical names, as names like "Blue Gum" can mean different species depending on where you are.
Some of the eucalyptus species produce extremely good timber with high durability, others are not so good.
Your first step should be to identify what species you have. As a last resort there's a book on identifying eucalyptus but it's a tricky business. Better if you can find someone who knows. Next step is to obtain "Wood in Australia" by Keith Bootle and look up the properties of your tree. This book is the bible for these sorts of questions.
Comment from contributor E:
I agree that eucalyptus can be useful, however, as others have said, there are a wide variety of species and growing conditions also vary the qualities of the wood. They were originally brought from Australia in the 19th century as the native boat building woods were being used up.
Because a eucalyptus grows fairly rapidly, and some varieties had been used successfully in Australia, it was thought that they would form a good substitute for the native woods. Unfortunately, the species imported, and the growing conditions proved the importers wrong.
Apple
Question
Does apple wood have any use in woodworking?
Forum Responses
Yes, but the dust is bad for you and some people are allergic to it. Saw, sticker most quick, and lots of weight.
I had two trees about 18" in diameter sawed and kiln dried. The sawyer placed my wood on the bottom to weight it as it was drying and it moved every which way. The rest I am air drying for a year at least, with plenty of weight. Maybe it will stay a little straighter this time. Apple wood has a nice cream color when finished with oil and is very pretty. It turns good, too.
Apple does warp, but it has beautiful reds, browns, and gold streaks. It has a fine grain and turns well. The color mellows a little like cherry, but not as much. Quarter sawing gives a striking striped appearance. One of my favorites.
Be aware that many fruit trees, more often than not, are subjected to chronic spraying with various pesticides/fungicides, etc. This has to build up in the wood itself from direct contact and via the water/nutrient uptake process. Half-life of some of those compounds is lengthy. I'd definitely take extra precautions when working that wood with regards to inhalation of particulate.
Question
Is there a difference between poplar and aspen?
Forum Responses
Yellow poplar - Liriodendron tulipifera (this spelling may be a little off). It has a distinctive flower in the spring which looks like a tulip, only it is green in color, hence the "tulipifera". Also, it has brilliant yellow to rusty yellow foliage in the fall, hence the "yellow" in its common name. It's fine stuff!
The leaf of yellow poplar is shaped like a tulip as well.
Aspen has very small leaves that shake and shimmer at the slightest breeze. Aspen grows in New England, the Lake States and the Rockies in large areas. Y-P tends to be mostly in the Appalachians and the South. Aspen is seldom over 18" in diameter; y-p is often over 30". Aspen is lightweight and white colored; y-p is often green with darker streaks in the heartwood and is medium in weight.
Gene Wengert, forum technical advisor
Aspen wood is very white. Because of this, it is ground on a large stone to produce what is referred to as groundwood. The fiber is then mixed with water and used to make newsprint. That is why a newspaper browns in a few weeks - it hasn't been bleached (very inexpensive). Yellow poplar is a very good wood for structural building. Most of the barns around here are made of poplar instead of pine studs. Several houses are sawn out of poplar.
Here in Northern Lower Mi we've got two kinds of aspen. Big tooth, which is named for the serration on its leaves and quaking or trembling. Big tooth is a better quality tree and will get very large. I cut some this winter with a 30" DBH that are white to the center. They are going to be my new mill building. Our trembling aspen can also make good lumber and get pretty big, but tends to go bad before getting too large. Big tooth also has a yellowish tinge to the bark, while the other is whiter.
Last week a tree service brought me 3 picker truck loads of what they called poplar. I have sawn thousands of feet of poplar and I know what it is. A lot of what they brought I think is aspen. Another tree service said it's popple. Is that the same as aspen?
Leaf scars are unmistakable even in winter with no leaves. When leaves are on, ID easy.
I have heard big tooth aspen referred to as silver popple. I guess that some might confuse popple with poplar.
The names for aspen include popple, poplar, quakie, trembling aspen, quaking aspen, silver poplar, white poplar, bigtooth aspen, aspen, etc.
Gene Wengert, forum technical advisor
If anyone is interested in seeing some very large specimens of Tulip Poplar, check out Joyce Kilmer Memorial Forest in Southwestern NC. I am talking 6 foot through on some of them. The information says it is the largest tract of virgin forest east of the Mississippi. It is a definite must see for tree buffs.
I am working on forest improvements on my own wood lot, done a little logging and a lot of cutting for firewood. But some sections have plenty of poplar and there is not much market for them, at least not in terms of stumpage value. It breaks my heart to have to drop and leave a tree with 200 bd ft in it to rot because it is competing with a nice cherry log. I'd like to find a market for this poplar. I have had about a thousand board feet cut into 1x material and I use it for lots of different stuff. But poplar dries slow and is hard to plane with moisture in it. Any marketing ideas?
Aspen is splinterless, so it is ideal for sauna seats and children's toys. Very often used for pallets, as it is lightweight, odorless, tasteless, and easy to print on, etc. Several reports have been written about uses for aspen by the US Forest Service - try the Rocky Mountain station in Ft. Collins for their aspen reports.
Gene Wengert, forum technical advisor
Great for painted products like beaded T&G, upholstered furniture frames, drawer boxes, chopsticks.
