Workbench top - Birch wood

Re: Workbench top - Birch wood

Denis Ch�nard, Orl�ans, Ont.

>IMO, more than strong enough, but too soft, it will dent easily.

If you don't mind the dings and bruises, yellow birch is actually stronger than maple.

DC

Re: Yellow v. paper birch

Dave Mount

>Denis--

I'm wondering if your experience with birch might be with paper birch rather than yellow birch. There's quite a difference. I use both frequently -- I would agree that paper birch will dent fairly easily as hardwoods go, but yellow birch is pretty hard. I don't have numbers at hand, but I believe it's up in the white oak/hard maple territory in strength in compression perpendicular to the grain (which I believe is the appropriate index for resistance to denting). Someone else can probably chime in with the numbers.

From my perspective, I'd say yellow birch would be a great choice for a bench. Unfortunately, paper and yellow birch are often marketed together without distinction, so you need to be careful about what you're getting.

Best,

Dave

Re: Yellow v. paper birch

Mike Hamilton

>I think yellow birch is hard enough to be an acceptable alternative to hard maple for the turned parts to Windsor chairs as well.

Regards,

Mike Hamilton

Yellow birch vs. maple dent resistance

Frank D. in Montreal

>The janka scale is used to measure resistance to compression perpendicular to the grain.

Here's a link with some results. Yellow birch comes in almost as dent resistant as red oak, both less resistant than maple. IMO for a bench yellow birch is more than tough enough for a bench. I have a softwood bench and find it acceptable (in fact I like a little give to the bench surface). If I need an anvil I just use a scrap piece of wood, a metal plate, or...an anvil.

Oops: the link  *LINK*

Frank D. in Montreal

>


the link (click here)

Two different concepts here

Denis Ch�nard, Orl�ans, Ont.

>Hardness and strength are two different properties. Hardness is the resistance to denting, and Frank's values are accurate.

Strength is another matter. It's the measure of resistance to deformation before failure occurs. I dug out my Wood Handbook from the Forest Products Labs, and this is what they have to say:

Modulus of rupture (kPa):

Yellow birch: 114,000 Sugar (hard) maple: 109,000

Modulus of elasticity (MPa):

Yellow birch: 13,900 Sugar (hard) maple: 12,600

Work to maximum load (kJ/m3):

Yellow birch: 143 Sugar (hard) maple: 114

Impact bending (mm):

Yellow birch: 1400 Sugar (hard) maple: 990

Maple wins handily in compression, shear and hardness measures.

Bottom line, if you want structural strength, use yellow birch. If you want something that resists denting and deformation, use hard maple. Listed densities are I believe within statistical precision (0.62 vs. 0.63)

Anecdote here, in my previous house I installed a yellow birch floor. It took one year of a toddler and a baby playing on it to dent it beyond tears... I saved a few dimes a bf compared to maple when I purchased the flooring... Talk about silly savings...

BTW, white (paper) birch is noticeably weaker and softer than the yellow type, I've used enough of both to confirm this. Yet sometimes you get a plank of white birch that's hard as heck, I don't know what causes that...

DC

Are your numbers swap?

Wendell @ Murphy, Tx

>The values you listed for birch are higher across the board. It's been a while since I took material science but doesn't higher mean "harder, tougher, stiffer, etc." in most of the categories?

Wendell

Nope

Denis Ch�nard, Orl�ans, Ont.

>I didn't list the numbers for crushing and shear values, where maple is higher, but if you insist...

Compression parallel to grain (kPa):

Yellow birch 56,300 Sugar maple 54,000

Compression perpendicular to grain (kPa):

Yellow birch 6,700 Sugar maple 10,100

Shear parallel to grain (kPa):

Yellow birch 13,000 Sugar maple 16,100

Tension perpendicular to grain (kPa):

Yellow birch 6,300 Sugar maple NA

Side hardness (N), a modified Janka test:

Yellow birch 5,600 Sugar maple 6,400

All figures are for 12% moisture content samples.

It's worth noting that for shear strength in "commercially important woods grown in the United States", only shagbark hickory, black locust and live oak surpass maple.

DC

Re: I knew what you meant, but stand corrected

Dave Mount

>Hi Denis--

I recognized what you were talking about. Everything you are talking about is a strength property, they are just different types of strength. Strength in compression perpendicular to the grain is considered a "strength" property (see Hoadley, Chapter 6), but it is the strength property related to denting of the face of a board. The properties related to load bearing as in a beam are involved with static bending strength. Beam strength under load incorporates aspects of stiffness (how much it deflects under load) and breaking strength (how much it will hold before it actually fails). Some stiff woods are weak when it comes to breaking under load, and some flexible woods are very resistant to breaking. Anyway, we were talking about the same things even if using different terms.

What I did have wrong is my recollection that yellow birch was close sugar maple in compression perp to the grain. Paper birch is given in Hoadley as 740 psi while yellow birch is 1190 psi (which matches both our experiences), but sugar maple is way up at 1810 psi. So you were absolutely right that there is quite a gap between sugar maple and either birch. I still wouldn't hesitate to use yellow birch for a benchtop, but your point that it will dent easier than maple is clearly true from the figures above. It's a matter of personal choice, doesn't make my opinion right or yours wrong.

Re: your floors, it's all relative. I put a hickory floor in our kitchen (2170 psi, much harder than sugar maple) and we've still managed to dent it by dropping cans and jars on it. It all dents eventually, just a matter of degree.

Best,

Dave

Birch benchtops

Edward inVancouver

>Not to muddy the waters, but if you want glued up birch countertops at a reasonable price, 25" and 36" widths, 6', and 8' lengths, and 1 1/2" thick, it is available, not from your local lumberyard but from....(drum roll please...)

Ikea.

Mind you for the same price they have solid beech and red oak countertops too. Personally I'd go for the beech over the birch.