Taken from specifications quoted by my suppliers.
All data should be used as a guide only, and not an exact specification.
Fabric weight and thickness
Tables of Weights and Measures
| Fabric | Metric Equivalent1 | Thickness (imperial)2 | Thickness (metric)1,2 |
|---|---|---|---|
| 2.3 oz/yd² fiberglass (plain weave cloth) | 78 gm/m² | 0.004″ | 0.10 mm |
| 6.0 oz/yd² fiberglass (plain weave cloth) | 203 gm/m² | 0.007″ | 0.17 mm |
| 5.0 oz/yd² Kevlar™ (plain weave cloth) | 170 gm/m² | 0.010″ | 0.25 mm |
| 5.8 oz/yd² Carbon Fiber (plain weave cloth) | 197 gm/m² | 0.009″ | 0.23 mm |
| 9.0 oz/yd² Carbon Fiber (unidirectional) | 305 gm/m² | 0.011″ | 0.28 mm |
1 calculated values, approximate.
2 dry fiber thickness – to obtain total layup thickness, sum the dry fiber thickness of each individual layer, and then multiply by a weighting factor for laminated thickness; this factor may be greater than 1 for a hand layup, and less than one for a vacuum-bagged layup. Finally, add the estimated thickness of any final epoxy topcoat or paint.
For a simple layup of one layer of 6oz ‘glass and one layer of 2.3 oz ‘glass, with a topcoat of epoxy, you can safely assume a skin thickness of 0.5 mm per side, for a total of 1mm added to the overall thickness of the foil. This will be correct within any reasonable fabrication tolerances.
Wood Density and Strength
| Species | Specific Gravity | Density @ 8% Moisture | Density @ 12% Moisture | Modulus of Elasticity @ 12% | Compressive Strength @ 12% |
|---|---|---|---|---|---|
Western Red Cedar |
0.33 |
356 kg/m3 22 lb/ft3 |
369 kg/m3 23 lb/ft3 |
7,700 MPa 1,110,000 psi |
31,400 kPa 4,560 psi |
Sitka Spruce |
0.42 |
454 kg/m3 28 lb/ft3 |
470 kg/m3 29 lb/ft3 |
9,900 MPa 1,570,000 psi |
35,700 kPa 5,610 psi |
Alaskan Yellow Cedar |
0.46 |
497 kg/m3 31 lb/ft3 |
515 kg/m3 32 lb/ft3 |
9,800 MPa 1,420,000 psi |
43,500 kPa 6,310 psi |
Douglas Fir |
0.50 |
540 kg/m3 34 lb/ft3 |
560 kg/m3 35 lb/ft3 |
12,600 MPa 1,790,000 psi |
47,600 kPa 6,900 psi |
Phil. Mahogany |
0.54 |
583 kg/m3 36 lb/ft3 |
605 kg/m3 38 lb/ft3 |
11,200 MPa 1,630,000 psi |
— |
White Ash |
0.63 |
680 kg/m3 42 lb/ft3 |
705 kg/m3 44 lb/ft3 |
12,000 MPa 1,740,000 psi |
51,100 kPa 7,410 psi |
Core-Cell LP1200 |
— |
200 kg/m3 12 lb/ft3 |
200 kg/m3 12 lb/ft3 |
42,441 psi??? |
500 psi |
Compiled from various sources found online, may contain errors. There is variability from tree-to-tree and even plank-to-plank within each species.
8% Moisture Content is typical of kiln dried lumber.
12% Moisture Content is typical of air dried lumber.
Compressive strength measured is parallel to grain.