Log Grading

Log Grading
- What & Why?
- Stautory Log Grades
  - products & grades
    - premium lumber
      - D E F G
    - veneer
      - (A) B & C
    - standard lumber
      - H I J
    - shake/shingle
      - K L M
    - utility (crap) lumber
      - U X
    - pulp
      - Y
    - firmwood reject
      - Z
  - Table: Grade by Species
- Grades vs. Sorts
  - high grade (350)
  - peeler (180)
  - standard (saw log) (120)
  - gang (small saw log) (70)
  - pee wee
  - utility (50)
  - large pulp / pulp (40)
  - boom sticks
  - poles
- Useful definitions
  - fractures (check, shake, shatter)
  - slab
  - "cut"
    - %V
    - %L
      - %C
      - %M
    - % ML
    - %SS
    - ** min length for lmbr = 2.5m
  - trim allowance (=grade consideration)
    - 1 rad "donut"
    - 11 rad heart rot ... trim = 13 rads
  - firmwood reject
    - too small/rotten to be processed
    - (Johnny) Rotten
      - <50% sound collar
    - short
      - < 1.2m net Length
    - skinny
      - < 5 R net @ butt
      - portion of log <5R
- "The Card" & Grading thought process
  - "start at the top"
  - consider
    - size (top & L)
    - % cut (= product)
    - knots
    - other 'defects'
- Log Characteristics
  - Top Radius
    - gross ave measure, not net
    - all have min, J also has max (8-18)
    - long logs @ 12.8m
  - Length
    - gross measure
  - Knots
    - knot indicators
    - NOT shoulder
    - right angle, max. for peelers
    - OLK for S/L, 1/3m, but 2/3m for large X
  - Rot
    - heart rot: 5 rad collar minimum for lumber
    - extra 1 rad of trim allowance (not sap rot)
    - conk knot ... 100% of length
      - need 2.5m for lmbr
    - grade consideration vs. vol. ded'n
  - Ring Count
    - 1/3 of radius, in from surface
    - need to ÷ 6
    - e.g. 30 rads ÷ 6 = 5 rad from surface
    - count rings "in that rad"
  - Twist (spiral grain)
    - measured where 'representative'
    - offset is measured over 30 cm (15 rads) of length
    - % twist = offset (rads) / top (rads)
    - max % and max offset (cannot exceed either)
  - Off Centre
    - measure 'offset' of pith
    - % offset = offset rads / top rads
    - 10% max for peelers
  - Sweep/ Crook/ Pistol Grip
    - sweep vs crook vs pistol grip
    - "pencil buck" the log into 'defect' and lumber
    - for sweep ... "pencil buck" into 2 smaller logs
  - Fractures & Bark Seams
    - 1 rad trim allowance
    - calc % loss
  - Deep Checks & Shake
    - internal - extra rad trim allowance
    - external - determine suitable core
  - Pests
    - Ambrosia
      - generally no vol or value ded'n
      - perhaps for premium lmbr if extreme
    - Powder Worm (CE)
      - no vol ded'n
      - not allowed in D,F,H, K, L, M
    - Toredo
      - no vol or grade ded'n
  - Stain
    - no stain in premium lumber or peelers
  - Pitch
    - consideration for premium lumber & peelers