| Balsa |
8 |
72 |
70 |
75 |
| Balsa |
10 |
100 |
100 |
100 |
| Balsa |
14 |
156 |
161 |
149 |
| Spruce |
28 |
230 |
260 |
289 |
| Yellow Pine |
28 |
222 |
277 |
288 |
| Douglas Fir |
30 |
241 |
291 |
341 |
| Hickory |
50 |
379 |
638 |
514 |
| Oak |
48 |
295 |
430 |
366 |
| Basswood |
26 |
261 |
288 |
288 |
| Black Walnut |
37 |
301 |
506 |
512 |
| From Wikipedia:
Ochroma pyramidale, commonly known as the balsa tree, is a large, fast-growing
tree native to the Americas. It is the sole member of the genus Ochroma. The name
balsa comes from the Spanish word for "raft." |
 Balsa is one of the lightest woods available,
and in many respects has the highest strength-to-weight ratio of any wood - even
oak. The chart at the right gives a comparison of a few familiar wood types.
Hobby grade balsa is harvested in the jungles of Ecuador, kiln dried, cut into
large blocks, and shipped to the U.S. for final cutting and sanding. Most balsa
from hobby shops is in the 8-10 lbs/ft3 realm. The rock-hard stock that
nobody wants is sent to the airplane kit manufacturers ;-) The vast majority of
the balsa wood I use for building model airplanes comes from
Sig, Midwest, and
Balsa USA. Other suppliers
have materialized in the past few years.
Since the rise of mammoth
wind turbines for electricity generation, balsa's use as a core material for
blades has caused a severe shortage in the modeling realm. Balsa prices have skyrocketed
in the past decade. Substitutes for balsa wood are being frantically sought. See:
Wuhan Flu Outbreak Leaves China Short on Balsa for Turbine Blades," "Balsa Shortage
Threatens Wind Power Rollout," "The Wood Behind the Wind."
Before being discovered as an ideal source of wood for model airplanes, balsa
trees were cut and assembled into raft for floating down the river. In fact, the
word "balsa" is Spanish for the word "raft." Balsa has been widely used by the military
for air-drop pallets, and in fact, during World War II, balsa wood for models became
scarce because the Army Air Force needed it for operations. Bamboo and other reeds
were tried by modelers as a substitute wood, but it never could replace balsa.
The charts below for weights of standard hobby shop balsa sheets, sticks and
blocks were calculated from a simple formula that takes the density of the of each
piece of balsa and multiply it by the volume. For 48" lengths, multiply each 36"
value by 4/3 (1.333).
Example:
A 3/16" x 3" x 36" sheet of balsa has a volume of 20.25 cubic inches (in3),
which is equal to 0.01171875 cubic feet (ft3). A piece of balsa with
a density of 8 lbs/ft3 is the same as a density of 128 oz/ft3.
So, to find the weight of the balsa sheet, multiply 128 oz/ft3 by 0.01171875
ft3 to get 1.500 oz. A 48" length would weigh 1.500 oz. x 4/3 = 2.000
oz.
BALSA SHEETS
Weight in Ounces, Density in Pounds/Foot3
| 1/32"x2" 1/32"x3"
1/32"x4"
|
0.125 0.188
0.250
|
0.167 0.250
0.333
|
0.211 0.313
0.417
|
0.250 0.375
0.500
|
0.291 0.438
0.583
|
0.333 0.500
0.667
|
| 3/32"x2" 3/32"x3"
3/32"x4"
|
0.375 0.563
0.750
|
0.500 0.750
1.000
|
0.625 0.938
1.125
|
0.750 1.125
1.500
|
0.875 1.313
1.750
|
1.000 1.500
2.000
|
| 3/16"x2" 3/16"x3"
3/16"x4"
|
0.750 1.125
1.500
|
1.000 1.500
2.000
|
1.250 1.875
2.500
|
1.500 2.250
3.000
|
1.750 2.625
3.500
|
2.000 3.000
4.000
|
| 3/8"x2" 3/8"x3"
3/8"x4"
|
1.500 2.250
3.000
|
2.000 3.000
4.000
|
2.500 3.750
5.000
|
3.000 4.500
6.000
|
3.500 5.250
7.000
|
4.000 6.000
8.000
|
| 1/16"x2" 1/16"x3"
1/16"x4"
|
0.250 0.375
0.500
|
0.333 0.500
0.667
|
0.417 0.625
0.833
|
0.500 0.750
1.000
|
0.583 0.875
1.167
|
0.667 1.000
1.333
|
| 1/8"x2" 1/8"x3"
1/8"x4"
|
0.500 0.750
1.000
|
0.667 1.000
1.333
|
0.833 1.250
1.667
|
1.000 1.500
2.000
|
1.167 1.750
2.333
|
1.333 2.000
2.667
|
| 1/4"x2" 1/4"x3"
1/4"x4"
|
1.000 1.500
2.000
|
1.333 2.000
2.667
|
1.667 2.500
3.333
|
2.000 3.000
4.000
|
2.333 3.500
4.667
|
2.667 4.000
5.333
|
| 1/2"x2" 1/2"x3"
1/2"x4"
|
2.000 3.000
4.000
|
2.667 4.000
5.333
|
3.333 5.000
6.667
|
4.000 6.000
8.000
|
4.667 7.000
9.333
|
5.333 8.000
10.667
|
BALSA BLOCKS
Weight
in Ounces, Density in Pounds/Foot3
| 1"x1" 1"x1½"
1"x2"
1"x2½"
1"x3"
|
2.000 3.000
4.000
5.000
6.000
|
2.667 4.000
5.333
6.667
8.000
|
3.333 5.000
6.667
8.333
10.00
|
4.000 6.000
8.000
10.000
12.000
|
4.667 7.000
9.333
11.667
14.000
|
5.333 8.000
10.667
13.333
16.000
|
| 2"x2" 2"x2½"
2"x3"
|
8.000 10.00
12.00
|
10.666 13.333
16.000
|
13.333 16.667
20.000
|
16.000 20.000
24.000
|
18.667 23.333
28.000
|
21.333 26.667
32.000
|
| 3"x3" 3"x4"
|
18.00 24.00
|
24.00 32.00
|
30.000 40.000
|
36.000 48.000
|
42.000 56.000
|
48.000 64.000
|
| 1½"x1½" 1½"x2"
1½"x2½"
|
4.500 6.000
7.500
|
6.000 8.000
10.00
|
7.500 10.000
12.500
|
9.000 12.000
15.000
|
10.500 14.000
17.500
|
12.000 16.000
20.000
|
| 2½"x2½" 2½"x3
|
12.500 15.000
|
16.667 20.000
|
20.833 25.000
|
25.000 30.000
|
29.166 35.000
|
33.333 40.000
|
BALSA STICKS
Weight in Ounces, Density in Pounds/Cubic3
| 1/16"x1/16" 1/16"x3/32"
1/16"x1/8"
1/16"x3/16"
1/16"x1/4"
1/16"x3/8"
1/16"x1/2"
|
16 16
8
8
4
4
2
|
0.125 0.188
0.125
0.188
0.125
0.188
0.125
|
0.167 0.250
0.167
0.250
0.167
0.250
0.167
|
0.208 0.312
0.208
0.312
0.208
0.312
0.208
|
0.250 0.375
0.250
0.375
0.250
0.375
0.250
|
0.292 0.438
0.292
0.438
0.292
0.438
0.292
|
0.333 0.500
0.333
0.500
0.333
0.500
0.333
|
| 1/8"x1/8" 1/8"x3/16"
1/8"x1/4"
1/8"x3/8"
1/8""x1/2"
|
4 4
4
2
1
|
0.125 0.188
0.250
0.188
0.125
|
0.167 0.250
0.333
0.250
0.167
|
0.208 0.312
0.416
0.312
0.208
|
0.250 0.375
0.500
0.375
0.250
|
0.292 0.438
0.538
0.438
0.292
|
0.333 0.500
0.667
0.500
0.333
|
| 1/4"x1/4" 1/4"x3/8"
1/4"x1/2"
1/4"x3/4"
1/4""x1"
|
1 1
1
1
1
|
0.125 0.188
0.250
0.375
0.500
|
0.167 0.250
0.333
0.500
0.667
|
0.208 0.312
0.416
0.625
0.832
|
0.250 0.375
0.500
0.750
1.000
|
0.292 0.438
0.583
0.876
1.166
|
0.333 0.500
0.667
1.00
1.333
|
| 1/2"x1/2" 1/2"x1"
|
1 1
|
0.500 1.000
|
0.667 1.333
|
0.832 1.666
|
1.00 2.00
|
1.166 2.333
|
0.1333 2.667
|
| 3/32"x3/32" 3/32"x1/8"
3/32"x3/16"
3/32"x1/4"
3/32"x3/8"
3/32"x1/2"
|
8 8
4
4
2
2
|
0.141 0.188
0.141
0.188
0.141
0.188
|
0.188 0.250
0.188
0.250
0.188
0.250
|
0.234 0.312
0.234
0.312
0.234
0.312
|
0.281 0.375
0.281
0.375
0.281
0.375
|
0.326 0.438
0.326
0.438
0.326
0.438
|
0.375 0.500
0.375
0.500
0.375
0.500
|
| 3/16"x3/16" 3/16"x1/4"
3/16"x3/8"
3/16"x1/2"
3/16"x3/4"
3/16"x1"
|
2 2
2
1
1
1
|
0.141 0.188
0.281
0.188
0.281
0.375
|
0.188 0.250
0.375
0.250
0.375
0.500
|
0.234 0.312
0.469
0.312
0.469
0.625
|
0.281 0.375
0.563
0.375
0.563
0.750
|
0.326 0.438
0.656
0.438
0.656
0.876
|
0.375 0.500
0.750
0.500
0.750
1.000
|
| 3/8"x3/8" 3/8"x1/2"
|
1 1
|
0.281 0.375
|
0.375 0.500
|
0.469 0.625
|
0.563 0.750
|
0.656 0.876
|
0.750 1.000
|
| 3/4"x3/4" |
1 |
1.125 |
1.500 |
1.875 |
2.250 |
2.625 |
3.000 |
|
