Cedar lumber
Moderator: admin
-
curiousgeorge
- Platinum Member
- Posts: 880
- Joined: Tue Feb 27, 2007 1:00 am
- Location: Fort Worth, Texas
Perhaps a brief discussion of the term relitive hunmidity is appropriate here. Basically, warm air can hold more moisture than cold air. For example, 90% relative humidity at 90 degrees air temperature is not at all the same as 90% relative humidity when the temperature is below freezing.
When we take that below freezing air and heat it to room temperature thru our furnaces the inside relative humidity drops dramatically, perhaps to less than 25% - dryer than the Sahara Desert - even though the quantity of moisture in the air, both outside and inside is the same. That's why it is called "relative" humidity.
Thus, if you take lumber from a yard, where it perhaps has had direct contact with moisture, and bring it into your heated shop, the wood is subjected to quite a shock. As Nick said, it can move quite a bit.
Bottom line: A relative humidity gauge on the wall is not going to be very helpful in determining if your wood is ready to use.
When we take that below freezing air and heat it to room temperature thru our furnaces the inside relative humidity drops dramatically, perhaps to less than 25% - dryer than the Sahara Desert - even though the quantity of moisture in the air, both outside and inside is the same. That's why it is called "relative" humidity.
Thus, if you take lumber from a yard, where it perhaps has had direct contact with moisture, and bring it into your heated shop, the wood is subjected to quite a shock. As Nick said, it can move quite a bit.
Bottom line: A relative humidity gauge on the wall is not going to be very helpful in determining if your wood is ready to use.
To add more considerations
Just to comment a regional difference in this thread that may be leading us astray. It seem to me that we are not discussing the same wood!
First of all- some of the folks are from the West Coast and Some from the Mid-West. We need to understand there are two entirely different woods in the U.S. that are both named "CEDAR". The cedar grown in the Northwest and used in outdoor construction is Western red cedar from the genus "Thuja". Mature trees are 150 to 200 ft tall and 4 to 8 ft in diameter. The wood is a tanish to greyish color, very soft, and light weight - used mostly for durability rather than strength. Specific Gravity is low - about .30. The wood absorbs water readily. One of the early uses of this wood (besides shingles) was to make pencils. If you have ever chewed on a pencil (as a kid) you can probably remember the "pecky" taste of this wood. (The taste is a good way to identify this wood). This tree normally grows in moist to wet shaded areas. It grows quite large, sometimes with diameters of over 4 feet and heights over 100 ft.
The "Cedar" that grows in the Mid-West is in the genus "Juniperus". It is an entirely different tree from Wester red cedar. It sometimes reaches diameters of 2 feet and heights of 80 ft. Its heartwood is a reddish color and has an aromatic presence that we call cedar smell. The wood is harder than the western red cedar and easily distinguished by taste alone. A similar wood is grown in the Western junipers but in smaller often shrub like trees.
I often wondered why folks from the East an Mid-West refer to the junipers that grow there as cedars. The answer became obvious after a while. When being settled - the local people thought these large juniper trees were cedars although the leaves (needles to some) have rounded scale-like parts rather than the more flattened scales of true cedars. The local common names (cedar) prevailed and would have continued without confusion - except the true cedars of the West were later discovered and they had to also be named cedar. So the confusion began.... Common names sometimes lead to confusion!
First of all- some of the folks are from the West Coast and Some from the Mid-West. We need to understand there are two entirely different woods in the U.S. that are both named "CEDAR". The cedar grown in the Northwest and used in outdoor construction is Western red cedar from the genus "Thuja". Mature trees are 150 to 200 ft tall and 4 to 8 ft in diameter. The wood is a tanish to greyish color, very soft, and light weight - used mostly for durability rather than strength. Specific Gravity is low - about .30. The wood absorbs water readily. One of the early uses of this wood (besides shingles) was to make pencils. If you have ever chewed on a pencil (as a kid) you can probably remember the "pecky" taste of this wood. (The taste is a good way to identify this wood). This tree normally grows in moist to wet shaded areas. It grows quite large, sometimes with diameters of over 4 feet and heights over 100 ft.
The "Cedar" that grows in the Mid-West is in the genus "Juniperus". It is an entirely different tree from Wester red cedar. It sometimes reaches diameters of 2 feet and heights of 80 ft. Its heartwood is a reddish color and has an aromatic presence that we call cedar smell. The wood is harder than the western red cedar and easily distinguished by taste alone. A similar wood is grown in the Western junipers but in smaller often shrub like trees.
I often wondered why folks from the East an Mid-West refer to the junipers that grow there as cedars. The answer became obvious after a while. When being settled - the local people thought these large juniper trees were cedars although the leaves (needles to some) have rounded scale-like parts rather than the more flattened scales of true cedars. The local common names (cedar) prevailed and would have continued without confusion - except the true cedars of the West were later discovered and they had to also be named cedar. So the confusion began.... Common names sometimes lead to confusion!
Octogenarian's have an earned right to be a curmudgeon.
Chuck in Lancaster, CA
Chuck in Lancaster, CA
Hi,
In some cases you just work with what you have and damp wood is sometimes what you get. In this case I was building a garden tool storage area and while the wood was far from dry it really didn't make much difference in this case. In fact, the fact it was wet and was going to shrink later was one way to make sure the project would work out.
In this case I built using the wet wood and having it butted tight together knowing that as it dried to a more normal level I would end up with some air flow, and this is what I wanted.
The first picture is a front view so you get the idea of what I was building. The second one is of the gap in the door. when I do a project like this I always go for an overlap and then hand plane the doors to fit and this is what I did this time too. As you can see, today the gap was about 1/4". The walls are somewhere in the 3/32" range... (again this depends on the level of moisture in the air) that can be seen in the third picture.
Ed
In some cases you just work with what you have and damp wood is sometimes what you get. In this case I was building a garden tool storage area and while the wood was far from dry it really didn't make much difference in this case. In fact, the fact it was wet and was going to shrink later was one way to make sure the project would work out.
In this case I built using the wet wood and having it butted tight together knowing that as it dried to a more normal level I would end up with some air flow, and this is what I wanted.
The first picture is a front view so you get the idea of what I was building. The second one is of the gap in the door. when I do a project like this I always go for an overlap and then hand plane the doors to fit and this is what I did this time too. As you can see, today the gap was about 1/4". The walls are somewhere in the 3/32" range... (again this depends on the level of moisture in the air) that can be seen in the third picture.
Ed
- Attachments
-
- DSCF4033src.jpg (233.12 KiB) Viewed 10977 times
-
- DSCF4035src.jpg (237.98 KiB) Viewed 10973 times
-
- DSCF4036src.jpg (236.04 KiB) Viewed 10971 times
{Knight of the Shopsmith} [Hero's don't wear capes, they wear dog tags]
Chuck,
Thanks for the reminder on the cedar types! Turns out that a few months ago I had salvaged aromatic (eastern) cedar from some deck posts, but the recent find of deck-surfacing wood is the western cedar.
Ed,
Nice technique and results on your cedar shed. That's one of the most straightforward proofs of dimensional changes I've seen, too.
Best Regards,
Thanks for the reminder on the cedar types! Turns out that a few months ago I had salvaged aromatic (eastern) cedar from some deck posts, but the recent find of deck-surfacing wood is the western cedar.
Ed,
Nice technique and results on your cedar shed. That's one of the most straightforward proofs of dimensional changes I've seen, too.
Best Regards,
Chris
Nick & Drew MADE me do this
Well,
I had gone without a jointer most of the year. But the Jointer Setting video had, attached to it, a real deal on new Jointers. I got one!
As a result, here is my chair I've been working on every now and then, totally from salvaged "trash" lumber, the past 6 weeks or so.
By the way, EVERYBODY is posting great projects lately. I would dominate the message boards if I complimented all of them....
Best Regards,
I had gone without a jointer most of the year. But the Jointer Setting video had, attached to it, a real deal on new Jointers. I got one!
As a result, here is my chair I've been working on every now and then, totally from salvaged "trash" lumber, the past 6 weeks or so.
By the way, EVERYBODY is posting great projects lately. I would dominate the message boards if I complimented all of them....
Best Regards,
- Attachments
-
- Cedar Chair.jpg (25.74 KiB) Viewed 10971 times
Chris
-
RobertTaylor
- Platinum Member
- Posts: 569
- Joined: Mon Sep 03, 2007 9:28 am
- Location: North Canton, Ohio