OREGON STATE UNIVERSITY

Testing Willamette Valley Ponderosa Pine

exploring properties of willamette valley ponderosa pine
Caption: 

Exploring the Properties of Willamette Valley Ponderosa Pine

Ponderosa pine is one of the most widely-distributed pine species in western North America; it extends from western Canada to central Mexico. There is a unique population of the species in western Oregon known as Willamette Valley ponderosa pine or simply as 'Valley pine.'  As is generally the case, wood properties vary with growing conditions - and little is currently known about the wood properties of Valley pine.

In the winter of 2017, we began 'the Valley Pine wood quality project'; we will be determining several commonly-reported wood properties including:

  • Specific Gravity (similar to density) - green, 12% moisture content, and ovendry (i.e., 0% moisture content)
  • Hardness (often called Janka hardness) - green and at 12% moisture content
  • Shrinkage - green to ovendry
  • Bending strength and stiffness (MOR and MOE) - green and at 12% moisture content
  • Machinability - quality of shaped specimens with a CNC router
  • Permeability - ability to accept commonly used wood preservatives

Source: Silvics of North America: Volume 1 - Conifers

Green property testing began in mid March and was completed on May 11th.  Kiln drying (to get to 12% moisture content for dry property testing) of remaining boards began 4/27/2017 and finished 5/5/2017.

Dry property testing was completed 7/10/2017. 

Machinability testing was completed 6/10/2018.

Permeability testing to be conducted late June, 2018.

(Last update 6/18/2018)

Tree No. Age

Top/Butt Diameter
(in.)

Elevation (ft.) Crown Class Comments
1 89 19.5/21.75 980 Dominant marginal Douglas-fir site
2 39 9.25/14.5 570 Intermediate  
3 29 11/21 590 Super Dom. very rough, knotty
4 ~100 18/19.5 700 Dominant  some sapstain

 

Tree No. - Log Segment

MOR (psi)
Bending Strength (green/12%)
[sample size]

MOE (x106 psi)
Bending Stiffness (green/12%)
[sample size]

Hardness (lbs.)(green/12%)
[sample size]

Specific gravity
(green/12%/ ovendry)
[sample size]

Shrinkage (%) -
green to ovendry
Tangential/Radial
[sample size]

1- second log 5092/8120 [18,15]
0.85/1.09 [18,15] 411/474 [11]
0.38/0.40/0.45 [13]
5.56/3.83 [10]
1 - butt log 6219/9499 [15,15] 0.97/1.31 [15,15] 483/564 [11,12]
0.44/0.46/0.49 [9]
5.15/4.06 [11]
2 - fourth log 5310/7051 [17,14] 0.92/0.97 [17,14] 312/418 [11]
0.34/0.36/0.38 [22,21,22]
5.26/3.45 [10]
2 - third log 5146/7310 [17,17] 0.84/0.99 [16,17] 378/442 [11,10] 0.33/0.36/0.38 [15] 5.49/3.43 10]
2 - second log 5719/9546 [17,14] 1.04/1.39 [17,14] 487/531 [12,11]
0.43/0.44/0.49 [22,18,22]
5.76/4.20 [13]
2 - butt log 5914/8480 [17,16] 1.01/1.12 [17,16] 559/642 [10,8]
0.45/0.48/0.52 [16,15,16] 6.33/4.92 [10]
3 - third log 3511/5923 [17,15] 0.42/0.74 [17,15] 258/311 [11,10]
0.29/0.32/0.34 [23,22,23] 5.19/2.88 [10]
3 - second log 4555/8412 [16,16] 0.72/1.11 [15,16] 286/417 [10,14]
0.43/0.46/0.51 [8] 6.14/3.04 [10]
3 - butt log 3401/5315 [14,17] 0.33/0.52 [15,17] 307/452 [11,10]
0.36/0.39/0.41 [18]
5.81/3.29 [10]
4 - second log 6313/9320 [15,16] 1.08/1.23 [15,16] 415/539 [10,9]
0.48/0.53/0.57 [13,12,13]
5.67/4.96 [10]
4 - butt log 5631/8065 [16,13] 1.07/1.22 [15,13] 452/489 [10,11]
0.44/0.45/0.48 [8] 5.44/3.84 [10]
Overall Average 5165/7913 0.84/1.06 395/480 0.40/0.42/0.46 5.62/3.81
Ponderosa pine (from USDA Wood Handbook) 5100/9400 1.0/1.29 320/460 0.38/0.40/? 6.2/3.9

Machinability Results

Fifty-four specimens were machined on a CNC router following a modified version of ASTM D1666 - Conducting Machining Tests of Wood and Wood-Base Panel Materials.  Materials were conditioned to 20C and 65% relative humidity and machined at a spindle speed of 2400 rpm and a feed rate of 346 inches/minute.  Following machining, all materials were examined for surface quality.  The standard specifies grading for raised grain, fuzzy grain, chipped grain, and rough-end grain.  However, the only significant machining issues were fuzzy grain and rough-end grain. The table below is a tally of the number of pieces assigned to each category.  A sample image of each of the 4 'grades' is shown in the images below. 

Subjective assessment results like these are difficult to interpret.  Some general observations are that Willamette Valley ponderosa pine may have some issues with fuzzy grain when machining. The wood from the different trees and log segments performed similarly with respect to machining, however, there may be some correlation between tree age and machining quality in that results were best for the oldest tree and worst for the youngest tree.

Tree No. - Log Segment

1 - Minor rough
end grain

2 - Significant rough
end grain

3 - Fuzzy grain (full
length of piece)

4 - Chipped grain

Average Score
(for tree)

1- second log   4 2    2.25
1 - butt log 2 1 3

2 - fourth log 1 1 1
1

  2.13
2 - third log 1 4 1  
2 - second log    

2 - butt log   4 2
 
3 - third log   3 2    2.38
3 - second log   2 3
 
3 - butt log 1 3 2

4 - second log 1 3 1

 1.8
4 - butt log 2 3
 

 


Logs for study after arrival at sawmil; logs represent 4 trees (marked by color) and 11 log segments (butt log, second log, etc.)

Dick Flynn, Custom Cut Lumber in Eugene, OR sawing log from Tree 3 (butt log)

 
Lumber loaded for delivery to OSU.


Kelly Currans, senior in Renewable Materials, preparing green slabs to be sawn into test specimens at OSU


Testing bending strength of green lumber


Testing hardness of green lumber

Boards being loaded into the dry kiln (4/27/17)

Danielle Korthuis, summer student intern, testing specific gravity (6/26/17)

Katherine Leavengood, summer student intern, preparing sample boards for permeability testing (6/30/2017)

Niko Hansen, summer student intern, preparing sample boards for permeability testing (7/12/2017)

 

 

Examples of results of machining test - from left to right 1) minor fuzzing on end grain; 2) fuzzing on end grain; 3) fuzzing full length; 4) chip out