A source for decent wood wedges...?

Lowes has some nice poplar planks for small projects. Poplar is a nice squeezable soft/hardwood. One small board should make dozens of wedges.

My best homemade wedges were from a sugar maple rifle blank, about 3" thick. Where I cut out details of the stock outline, I got scraps that were wedge shaped on one end and I would just cut them off to length.
 
Lowes has some nice poplar planks for small projects. Poplar is a nice squeezable soft/hardwood. One small board should make dozens of wedges.

My best homemade wedges were from a sugar maple rifle blank, about 3" thick. Where I cut out details of the stock outline, I got scraps that were wedge shaped on one end and I would just cut them off to length.
excellent advice and i like the idea of using scrap pieces of wood from another project.
 
First I am a hobbiest woodworker trying to learn about shrinkage. So I've got lots of questions.


The inset graphic is correct in that for most species the radial shrinkage is usually more than tangential, and for all species, the longitudinal shrinkage is much smaller.
. . .
I think "radial" and "tangential" are reversed?


. . .
The trouble is, those figures are more in line with green to dry shrinkage(reflecting the interests of the industry that funds research, unsurprisingly) Figures I've seen for shrinkage/swelling due to seasonal %RH changes are much smaller, around a percent instead of 4%-8%.. . .
I know absolutely nothing about the industry. Are you saying the industry gains some benefit from using "green to dry shrinkage" ratios? How do they benefit? Is this significant enough to consider when using the lumber in cabnetry, furniture, etc.? What is the alternative procedure to the "green to dry" measurement?


. . . The ratio between radial and longitudinal is also lower for hardwoods, typically 1.3 down to parity. Softwoods maintain the ratio of 2 you see in the graphic however.
This topic has so far been about a percentage comparison. For example {1%-2%, 2%-4%. 4%-8%, ...} all have the same ratio but will result in different dimensions.

Bob
 
Lowes has some nice poplar planks for small projects. Poplar is a nice squeezable soft/hardwood. One small board should make dozens of wedges.

My best homemade wedges were from a sugar maple rifle blank, about 3" thick. Where I cut out details of the stock outline, I got scraps that were wedge shaped on one end and I would just cut them off to length.


I have used Silver Maple for wedges- that stuff is all around my place. I just looked it up after you mentioned Sugar Maple and found out that it is a softwood.

It hasn't backed out of my maul or the couple of 16oz. hammers I have used it in. I have an axe that I wedged with it but to be honest I haven't used it yet.

JB sent me some Purple Heart that I have yet to use - that seems super hard.
 
Soft wood is generally used to mean a coniferous tree. The typical ones are your SPF lumber -- spruce, pine, fir -- but cedar, hemlock, and juniper fall into that category as well.

Silver maple is a soft maple, but it is still a hardwood. It just happens to be at the soft end of the spectrum. This is due to it's growth habit as an early successional tree where it grows fast and dies young so the wood density is lower than slower growing species such as sugar maple.
 

Hate to bring it up, but I think I found another typo. I believe Silver Maple is sometimes called Soft Maple (not categorized as a softwood) and Sugar Maple is Hard Maple.

Bob

Well Bob, I'm not surprised. Not so much of a typo as just wrong. I was thinking "softer" wood as opposed to "Softwood". I don't know wood like some of you guys do. I have instincts enough to not eat poisonous stuff and know when wood is dry enough to start a fire or green enough to bend.

So, school me on what I am getting at. Misinformation is bad and I don't want to push it.

BG_Farmer mentioned Sugar Maple and I thought of the Silver Maple from out back that I have used for wedges on a couple of tools. My trees.

Silver Maple is on the "soft" end of the Maples but Maples are classified as hardwoods. But it is not classified as a softwood tree, correct? It's still a hardwood but not suitable for steam bending, tool handles, load bearing, building, etc?

Amazing what a space between words can convey.

Did you knock this out?

29049005864_6359a1d764_b.jpg

Bob

1,000 words right there.
 
Soft wood is generally used to mean a coniferous tree. The typical ones are your SPF lumber -- spruce, pine, fir -- but cedar, hemlock, and juniper fall into that category as well.

Silver maple is a soft maple, but it is still a hardwood. It just happens to be at the soft end of the spectrum. This is due to it's growth habit as an early successional tree where it grows fast and dies young so the wood density is lower than slower growing species such as sugar maple.

Agreed.

I'll pay more attention.
 
First I am a hobbiest woodworker trying to learn about shrinkage. So I've got lots of questions.



I think "radial" and "tangential" are reversed?

They are indeed, thanks for catching that!



I know absolutely nothing about the industry. Are you saying the industry gains some benefit from using "green to dry shrinkage" ratios? How do they benefit? Is this significant enough to consider when using the lumber in cabnetry, furniture, etc.? What is the alternative procedure to the "green to dry" measurement?

Not really, all I meant is that the lumber industry is interested in minimizing the rough milled size when green to get a certain size dressed lumber after kiln drying. Most of the published figures for wood shrinkage reflect that - green to dry - rather than seasonal variation - seasoned or dried wood in varying %RH. For our purposes (and those of most woodworkers) these are the more interesting figures.



This topic has so far been about a percentage comparison. For example {1%-2%, 2%-4%. 4%-8%, ...} all have the same ratio but will result in different dimensions.

Bob

I meant that the figures I've seen for variation in seasoned woods are quite different from green to dry. You see shrinkage percentages that are far lower, and for hardwoods the ratio between the two directions are different as well - more like 1.1%/0.8% for example. For softwoods the percentages tend to be about half that of green to dry, but the ratio of tangential to radial remains roughly the same.

Unfortunately, I don't recall ever seeing realistic seasonal shrink/swell numbers actually published (doesn't mean they aren't somewhere, I've just not seen them). I have seen a couple blog type articles on the web put up by hobbyists interested in seasonal variation, and they usually conduct a small study with scraps and a hygrometer in a closed vessel with some water. The figures they report could be somewhat under-representative as they don't always say how long they leave the wood to reach its equilibrium moisture content (I would guess a week would be necessary). On the other hand, experience tells me that the ~1% figure is close to correct.
 
. . .
Silver Maple is on the "soft" end of the Maples but Maples are classified as hardwoods. But it is not classified as a softwood tree, correct? . . .
AFAIK, yes.


. . .
It's still a hardwood but not suitable for steam bending, tool handles, load bearing, building, etc?. . .
Mechanical Properties of Wood:
http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/ch04.pdf?

Lots of wood info here:
http://www.wood-database.com/


. . .
Did you knock this out?
. . .
Yes

Bob
 
I usually make my own wedges if I think the axe/hatchet is nice enough to warrant it. On a beat up user, I may not spend much time refining the replacement handle and just use the cheap nasty wedge that came with it. No sense spending 5 hours shaping and hanging a sweet haft when the end result will still only be worth $10 because of a worn/damaged head (that still has a lot of useable life in it).

I've started shaping my wedges for single bits differently now. It always seems like the thinner handle material in the front of the eye must compress more or something, and the wedge can be pounded in much deeper at the front (towards the bit) than it does at the poll. This naturally makes the wedge want to tilt forward or split while hammering it in. Anybody else notice this? So to compensate for this, I started tapering my wedges so that they get fatter towards the front of the eye, in addition to the taper in the normal direction. It seems to have helped so far. Also, I use a pine board to cushion the hammer blows, like Square Peg mentioned, and have also left some wedges very long at first like Lieblad said, and both do seem to help prevent splitting the wedge as well.
 
Seems to me a comprehensive table would be huge. Here is a possible alternative.

Unfortunately, that says it's green to dry, just like all the rest. It would be relevant if we used green wood for furniture and handles, but we don't. Once wood is dry, it does not swell or shrink as much with seasonal humidity as does green wood. That is why firewood rounds cut green will tend to crack by the time they've sat a few months before splitting, whereas furniture drawers that won't open in July do not crack (usually) when they go back to the proper size in the fall/winter.

I've yet to see a table that lists realistic figures for humid dry to dry-dry, only anecdotal stuff that a woodworker or two have come up with. I think the real figures lie somewhere in between the two.
 
Unfortunately, that says it's green to dry, just like all the rest. It would be relevant if we used green wood for furniture and handles, but we don't. Once wood is dry, it does not swell or shrink as much with seasonal humidity as does green wood. That is why firewood rounds cut green will tend to crack by the time they've sat a few months before splitting, whereas furniture drawers that won't open in July do not crack (usually) when they go back to the proper size in the fall/winter.

I've yet to see a table that lists realistic figures for humid dry to dry-dry, only anecdotal stuff that a woodworker or two have come up with. I think the real figures lie somewhere in between the two.

Wood movement is something that is still readily noticed by ordinary folks. A 2 3/4 X 3/4 inch hardwood (maple/birch/oak) floor can show up to 1/8" separation between the boards during the dead of winter in non humidified houses. It was an art (or part of a competent tradesman's lot) years ago to be able to judge flooring before it got nailed down and it helped to only do such work during the spring or in the fall when overall air humidity and moisture in the boards was 'middle of the road'. A floor banged down in late January inevitably heaved or buckled during the summer and a floor laid in hot humid late summer had the joints open up like crazy during the winter.
 
Wood movement is something that is still readily noticed by ordinary folks. A 2 3/4 X 3/4 inch hardwood (maple/birch/oak) floor can show up to 1/8" separation between the boards during the dead of winter in non humidified houses. It was an art (or part of a competent tradesman's lot) years ago to be able to judge flooring before it got nailed down and it helped to only do such work during the spring or in the fall when overall air humidity and moisture in the boards was 'middle of the road'. A floor banged down in late January inevitably heaved or buckled during the summer and a floor laid in hot humid late summer had the joints open up like crazy during the winter.

Yes, correct - assume 4" wide flooring (I know it tends to be more narrow these days) - 1/8" over 4" is 3% - more akin to the anecdotal figures I have seen reported for dry wood from the humid season to the dry season. Flooring is often flat or rift sawn, so if green wood were used you would see 2x to 3x the shrinkage normally observed (say for red oak) according to the tables posted everywhere.

I've not personally seen that degree of shrinkage, probably due to living in the desert southwest for decades. I don't remember seeing hugely extreme examples as a kid in Maine either though.
 
Unfortunately, that says it's green to dry, just like all the rest. . .
That is not what the paper is saying.

I understand that a piece of lumber once dried (from green to dry) and taken to my shop will then equalize (swell/shrink) to the relative humidity in my environment. If I use the USDA table from my post (#35) I can get at least a rough idea of the moisture change (%EMC) that that "dried" piece will undergo in one year at my location. The highest percent minus the lowest percent is the amount of annual change (Amc in the equation).


. . .It would be relevant if we used green wood for furniture and handles, but we don't. . .
Maybe not exactly relating to the point, but why do you assume that we don't use green wood for furniture?


. . .Once wood is dry, it does not swell or shrink as much with seasonal humidity as does green wood. . .
The seasonal differences shown in the USDA table (post #35) for "dried" wood are obviously less than the differences of green minus dry. The "Green to Oven Dry" differences are in fact shown in the table titled "Appendix III" (again post #35). Note that the main title is "Shrinkage Coefficients for Selected Woods". The appropriate value (SC) is selected and used in their equation to calculate the width change of a "dried" board.


. . .That is why firewood rounds cut green will tend to crack by the time they've sat a few months before splitting, whereas furniture drawers that won't open in July do not crack (usually) when they go back to the proper size in the fall/winter. . .
BTW "furniture drawers that won't open in July" don't "go back to the proper size in the fall/winter". If they were the "proper" size to begin with they would operate smoothly year around.


. . .I've yet to see a table that lists realistic figures for humid dry to dry-dry, only anecdotal stuff that a woodworker or two have come up with. I think the real figures lie somewhere in between the two.
First, is the Purdue University paper correct in calculating the "realistic" values you mention? If not then what is incorrect? The coefficients used, the equation? If you know the absolute correct way then please post.

Second, how would you construct the table? What would the row and column headings be?


Bob
 
That is not what the paper is saying.

I understand that a piece of lumber once dried (from green to dry) and taken to my shop will then equalize (swell/shrink) to the relative humidity in my environment. If I use the USDA table from my post (#35) I can get at least a rough idea of the moisture change (%EMC) that that "dried" piece will undergo in one year at my location. The highest percent minus the lowest percent is the amount of annual change (Amc in the equation).

I'm sorry, I missed the link in that series of images. Yes, the paper is saying roughly what I am saying - that the green to dry figures (which ironically are listed in their appendix III) only imply the expected change in use of seasoned wood. At the bottom of page three, the author says "In the case of sugar maple, for example, a change of 6 percent in the moisture content may result in a dimensional change in a furniture part of about 2.5 percent."

If you looked at a green-dry table you would expect on the order of 5% to 9% the way most people seem to view these tables. The table is basically not reporting the EMC changes seen in typical use and people assume that you will see that full 5%-9% swing from summer rain season to winter dry season. The EMC is actually changing by only 10% or so at worst (also reported in the introduction of the article).

Maybe not exactly relating to the point, but why do you assume that we don't use green wood for furniture?

Yes, there is one specialized application in the entirety of the furniture trade over the centuries of history of making furniture. I don't know much about it because it is not much to my taste, and being a hobbyist I can happily ignore the stuff I don't much care for. Come to think of it, I think Windsor chairs also take advantage of the green to dry shrinking to hold spindles tight in the seat, but again I don't know much about it.


The seasonal differences shown in the USDA table (post #35) for "dried" wood are obviously less than the differences of green minus dry. The "Green to Oven Dry" differences are in fact shown in the table titled "Appendix III" (again post #35). Note that the main title is "Shrinkage Coefficients for Selected Woods". The appropriate value (SC) is selected and used in their equation to calculate the width change of a "dried" board.

I typically see people posting the green-dry type tables and saying something like "you'll see 5-10% dimensional change, according to the table" without realizing that the EMC of seasoned wood in use is a much smaller range and will show a much smaller dimensional change - on the order of 1-3%. Since you seem to get this, I kinda wonder what we are debating? You seem to understand here that they were using one metric to estimate another. I'm simply saying that this leads the casual viewer to mistake in his estimation because of the gritty details of mathematics one must go through are typically buried in an appendix somewhere.


BTW "furniture drawers that won't open in July" don't "go back to the proper size in the fall/winter". If they were the "proper" size to begin with they would operate smoothly year around.

Sure, perhaps I should have said "normal size" or "size as constructed". Proper in this case is not used to mean "correct" so much as "median" and is only a sloppy bit of idiomatic english intended to make the sentence read more easily. While a well constructed piece will not have this problem, it certainly is common enough that most people have experienced it (which is why I use it as an example).

First, is the Purdue University paper correct in calculating the "realistic" values you mention? If not then what is incorrect? The coefficients used, the equation? If you know the absolute correct way then please post.

Correct in what sense? Calculating an expected trend based on %RH alone, which is taken as an estimate for seasoned wood changes in general (as in not specific to grain orientation or species)? If so, then yes, it is correct.

The dimensional change figures quoted in the green to dry table are not used in the equation listed in appendix II - that one only has temperature and %RH as variables.

The equation is without a doubt determined through experimentation, but it is also only a general equation. A more interesting way to do it would be to measure changes by species and grain orientation and then derive new equations for each. I would guess that the general equation would remain the same, but the constants would vary. I have never seen it done this way (as I've said before), except in one case (on some other hobbyist's website) where I expect he did not allow sufficient time for equilibration.

Second, how would you construct the table? What would the row and column headings be?

Which table? The one in Appendix III? There is nothing wrong with it at all, it is simply concerned with a different topic than the one the author is discussing. He's not talking about dimensional changes green-dry, so the table is not relevant.

A relevant table would have the same rows and columns but the data & title would reflect the changes from about 6% EMC to 15% EMC. If I remember correctly, above 15-16% EMC you are actually getting free water back in the wood cells, as in you would have to soak it in water - which is a different environment that picking up atmospheric moisture from humid air.
 
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