Wood Types |
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The species of wood, as well as its condition, have a dramatic effect on planing ability. The harder the wood (as illustrated by its shear strength), the more difficult it will be to plane.
Commonly used hardwoods and their associated shear strengths are illustrated in Figure 11. High shear means difficult planing.
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| Type | Shear (PSI) |
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| Black Locust |
| 2,480 |
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| Sugar Maple |
| 2,330 |
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| Increasing Difficulty |
| Pecan Hickory | 2,080 |
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| American Elm | 1,510 |
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| White Oak |
| 2,000 |
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| White Ash |
| 1,950 |
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| Black Cherry |
| 1,700 |
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| Black Walnut |
| 1,370 |
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| Red Alder |
| 1,080 |
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| Basswood |
| 980 |
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| Cottonwood |
| 930 |
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Figure 11. Common hardwood shear strengths.
Similarly, common softwood shear strengths are displayed in Figure 12.
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| Type | Shear (PSI) |
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| Western Larch | 1,410 |
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| Tamarack |
| 1,280 |
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| Increasing Difficulty |
| Douglas Fir |
| 1,160 |
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| Cypress |
| 1,000 |
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| Alaska Cedar |
| 1,130 |
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| Sitka Spruce |
| 1,150 |
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| Sugar Pine |
| 1,050 |
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| Redwood (OG) | 940 |
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| Red Cedar |
| 860 |
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| White Pine |
| 850 |
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| Balsam Fir |
| 710 |
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Figure 12.Common softwood shear strengths.
The species of wood, as well as condition, will affect planing ability. The harder the wood, the more difficult it will be to plane. We’ve included below, a list of wood characteristics you may encounter when planing. The following descrip- tions of defects will give you some possible answers to problems you may encounter while planing different materials. Possible solutions fol- low the descriptions.
Chipped Grain - usually a result of cutting against the grain, or planing wood with knots or excessive amount of cross grain. Chipped grain can also be caused by dull knives. Often, chipped grain can be avoided by taking shallow cuts. If those options do not work, inspect your lumber and determine if its grain pattern is causing the problem. If the wood does not show substantial crossgrain, inspect your knives for sharpness.
Fuzzy Grain - Usually caused by surfacing lum- ber with too high a moisture content. Sometimes fuzzy grain is a characteristic of some woods, such as basswood. Fuzzy grain can also be caused by dull knives or an incorrect grinding bevel. Check with a moisture meter. If moisture is greater than 20%, sticker the wood and allow to dry. Otherwise, inspect knife condition.
Glossy Surface - Usually caused by dull knives taking shallow cuts at a slow feed speed. Surface gloss will usually be accompanied by overheat- ing. Often, lumber will be scorched and eventual- ly, damage to knives will occur.
Snipe - Occurs when board ends have more material removed than the rest of the board. Usually caused when the workpiece is not prop- erly supported as it goes through the machine. However, a small amount of snipe is inevitable. The best way to deal with snipe is by planing lum- ber longer than your intended work length and then cutting off the excess after planing is com- pleted.
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| G8794 121⁄2" Portable Planer | |
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