manual for making toy planes

Finest Quality

Balsa WoodPlywood

BasswoodDowels

U.S. Consumer Price List

SIG MFG. CO., INC.401 South Front St. • Montezuma, IA 50171 • USA • Ph: 641-623-5154 • Fax: 641-623-3922

Web: www.sigmfg.com • Email: [email protected]

December 1, 2012

AAA BALSA WOODSince 1951 SIG has been providing model builders with the finest Balsa Wood available.

BALSA STICKS

STICKS - 36" Length

RETAIL MAP

SIGB001 1/16 X 1/16 0.25 0.21

SIGB002 1/16 X 1/8 0.26 0.22

SIGB003 1/16 X 3/16 0.34 0.28

SIGB004 1/16 X 1/4 0.36 0.30

SIGB005 1/16 X 3/8 0.41 0.34

SIGB006 1/16 X 1/2 0.51 0.42

SIGB007 1/16 X 3/4 0.58 0.48

SIGB008 1/16 X 1 0.75 0.62

SIGB009 3/32 X 3/32 0.24 0.20

SIGB010 3/32 X 1/8 0.29 0.24

SIGB011 3/32 X 3/16 0.31 0.26

SIGB012 3/32 X 1/4 0.35 0.29

SIGB013 3/32 X 3/8 0.53 0.44

SIGB014 3/32 X 1/2 0.62 0.51

SIGB015 3/32 X 3/4 0.79 0.66

SIGB016 3/32 X 1 0.99 0.82

SIGB017 1/8 X 1/8 0.34 0.28

SIGB018 1/8 X 3/16 0.37 0.31

SIGB019 1/8 X 1/4 0.41 0.34

SIGB020 1/8 X 5/16 0.53 0.44

SIGB021 1/8 X 3/8 0.62 0.51

SIGB022 1/8 X 1/2 0.58 0.48

SIGB023 1/8 X 3/4 0.88 0.73

SIGB024 1/8 X 1 1.00 0.83

SIGB025 3/16 X 3/16 0.55 0.46

SIGB026 3/16 X 1/4 0.55 0.46

SIGB027 3/16 X 3/8 0.60 0.50

SIGB028 3/16 X 1/2 0.76 0.63

SIGB029 3/16 X 3/4 0.92 0.76

SIGB030 3/16 X 1 1.23 1.02

SIGB031 1/4 X 1/4 0.58 0.48

SIGB032 1/4 X 3/8 0.75 0.62

SIGB033 1/4 X 1/2 0.83 0.69

SIGB034 1/4 X 3/4 1.17 0.97

SIGB035 1/4 X 1 1.41 1.17

SIGB036 5/16 X 5/16 1.13 0.94

SIGB037 5/16 X 3/8 0.90 0.75

SIGB038 5/16 X 1/2 1.11 0.92

SIGB039 5/16 X 5/8 1.44 1.20

SIGB136 3/32 X 2 1.62 1.34

SIGB137 1/8 X 2 1.73 1.44

SIGB138 3/16 X 2 1.96 1.63

SIGB139 1/4 X 2 2.20 1.83

SIGB140 3/8 X 2 2.75 2.28

SIGB141 1/32 X 3 1.58 1.31

SIGB142 1/20 X 3 1.36 1.13

SIGB143 1/16 X 3 1.30 1.08

SIGB144 3/32 X 3 1.47 1.22

SIGB145 1/8 X 3 1.83 1.52

SIGB146 5/32 X 3 2.15 1.78

SIGB147 3/16 X 3 2.22 1.84

SIGB148 1/4 X 3 2.80 2.32

SIGB149 5/16 X 3 3.22 2.67

SIGB150 3/8 X 3 3.30 2.74

SIGB151 1/32 X 4 2.09 1.73

SIGB152 1/16 X 4 2.10 1.74

SIGB153 3/32 X 4 2.53 2.10

SIGB154 1/8 X 4 2.90 2.41

SIGB155 3/16 X 4 3.45 2.86

SIGB156 1/4 X 4 4.80 3.98

SIGB157 3/8 X 4 6.60 5.48

SIGB158 1/16 X 6 3.55 2.95

SIGB159 3/32 X 6 3.88 3.22

SIGB160 1/8 X 6 4.23 3.51

SIGB161 3/16 X 6 4.82 4.00

SIGB162 1/4 X 6 5.95 4.94

SIGB163 3/8 X 6 8.10 6.72

SHEETS - 48" Length

RETAIL MAP

SIGB388 1/32 X 3 1.88 1.56

SIGB389 1/16 X 3 1.88 1.56

SIGB390 3/32 X 3 2.27 1.88

SIGB391 1/8 X 3 2.84 2.36

SIGB392 3/16 X 3 3.40 2.82

SIGB393 1/4 X 3 4.15 3.44

SIGB394 3/8 X 3 5.10 4.23

SIGB395 1/16 X 4 3.68 3.05

SIGB396 3/32 X 4 4.62 3.83

SIGB397 1/8 X 4 5.19 4.31

SIGB398 3/16 X 4 6.22 5.16

SIGB399 1/4 X 4 7.25 6.02

SIGB400 3/8 X 4 11.58 9.61

SIGB401 1/16 X 6 3.55 2.95

SIGB402 3/32 X 6 3.88 3.22

SIGB403 1/8 X 6 4.23 3.51

SIGB404 3/16 X 6 7.00 5.81

SIGB405 1/4 X 6 8.92 7.40

SIGB406 3/8 X 6 10.00 8.30

SIGB040 5/16 X 1 1.52 1.26

SIGB041 3/8 X 3/8 1.02 0.85

SIGB042 3/8 X 1/2 1.32 1.10

SIGB043 3/8 X 3/4 1.58 1.31

SIGB044 3/8 X 1 1.92 1.59

SIGB045 1/2 X 1/2 1.32 1.10

SIGB046 1/2 X 3/4 1.66 1.38

SIGB047 1/2 X 1 2.07 1.72

SIGB048 5/8 X 5/8 1.80 1.49

SIGB049 5/8 X 1 2.64 2.19

SIGB050 3/4 X 3/4 2.40 1.99

SIGB051 3/4 X 1 3.19 2.65

STICKS - 48" Length

RETAIL MAP

SIGB061 1/8 X 1/8 0.43 0.36

SIGB062 1/8 X 1/4 0.58 0.48

SIGB063 1/8 X 1/2 0.84 0.70

SIGB064 3/16 X 3/16 0.66 0.55

SIGB065 3/16 X 1/2 1.04 0.86

SIGB066 3/16 X 3/4 1.22 1.01

SIGB067 1/4 X 1/4 0.95 0.79

SIGB068 1/4 X 1/2 1.22 1.01

SIGB069 1/4 X 3/4 1.80 1.49

SIGB070 5/16 X 5/16 1.13 0.94

SIGB071 3/8 X 3/8 1.42 1.18

SIGB072 3/8 X 1/2 1.80 1.49

SIGB073 3/8 X 3/4 2.17 1.80

SIGB074 1/2 X 1/2 1.98 1.64

SIGB075 1/2 X 3/4 2.72 2.26

BALSA SHEETS

SHEETS - 18" Length

RETAIL MAP

SIGB183 3/32 X 3 2.01 1.67

SIGB184 1/8 X 3 2.03 1.68

SIGB193 1/8 X 4 2.08 1.73

SHEETS - 36" Length

RETAIL MAP

SIGB134 1/32 X 2 1.37 1.14

SIGB135 1/16 X 2 1.50 1.25

PRICES: The following U.S. price list shows two prices for each item - RETAIL and MAP. Unlike 20 years ago, most hobby shops in the U.S. today discount

their prices below full retail price. Thus the RETAIL price shown here is typically the maximum price that a hobby shop will charge for the item. The MAP

(Minimum Advertised Price) is the lowest price that hobby shops will sell the item for. SIG encourages you to support your local hobby shop. If your hobby

shop does not carry the SIG items you want, you can order direct from our web site at MAP price. The prices in this book are applicable in the United

States only. Due to high shipping costs, foreign customers should always buy from their local hobby dealer.

2

BALSA PLANKS

PLANKS - 36" Length

RETAIL MAP

SIGB206 1 X 1 4.43 3.68SIGB207 1/2 X 2 5.03 4.17SIGB208 3/4 X 2 5.87 4.87SIGB209 1 X 2 6.72 5.58SIGB210 1-1/2 X 2 10.19 8.46SIGB211 2 X 2 11.00 9.13SIGB212 1/2 X 3 5.99 4.97SIGB213 3/4 X 3 7.55 6.27SIGB214 1 X 3 9.70 8.05SIGB215 1-1/2 X 3 15.23 12.64SIGB216 2 X 3 16.70 13.86SIGB217 3 X 3 26.39 21.90SIGB218 1/2 X 4 9.23 7.66SIGB219 3/4 X 4 10.55 8.76SIGB220 1 X 4 13.58 11.27SIGB221 1-1/2 X 4 17.99 14.93SIGB222 2 X 4 23.39 19.41SIGB223 3 X 4 34.79 28.88SIGB224 1/2 X 6 13.19 10.95SIGB225 3/4 X 6 16.50 13.70SIGB226 1 X 6 19.79 16.43SIGB227 1-1/2 X 6 27.59 22.90SIGB228 2 X 6 35.99 29.87SIGB229 3 X 6 52.79 43.82

BALSA BLOCKS

BLOCKS - 3" Length

RETAIL MAP

SIGB251 1 X 1 0.26 0.22

BLOCKS - 6" LengthRETAIL MAP

SIGB266 1 X 1 0.83 0.69SIGB267 1/2 X 2 1.02 0.85SIGB268 3/4 X 2 1.14 0.95SIGB269 1 X 2 1.09 0.90SIGB270 1-1/2 X 2 2.03 1.68SIGB271 2 X 2 1.75 1.45SIGB274 1 X 3 1.70 1.41SIGB275 1-1/2 X 3 2.39 1.98SIGB276 2 X 3 2.40 1.99SIGB277 3 X 3 5.99 4.97SIGB278 1/2 X 4 1.67 1.39SIGB280 1 X 4 2.45 2.03

SIGB458 3/16 X 3 4.44 3.69SIGB459 1/4 X 3 5.10 4.23SIGB460 3/8 X 3 6.59 5.47SIGB461 1/16 X 4 3.83 3.18SIGB462 3/32 X 4 3.95 3.28SIGB463 1/8 X 4 4.62 3.83SIGB650 3/16 X 4 5.70 4.73SIGB645 1/4 X 4 6.95 5.77SIGB649 3/8 X 4 8.63 7.16

C-GRAIN - 36" Length

RETAIL MAP

SIGB470 1/32 X 2 1.74 1.44SIGB471 1/16 X 2 1.86 1.54SIGB472 3/32 X 2 1.98 1.64SIGB473 1/8 X 2 2.10 1.74SIGB477 1/32 X 3 2.39 1.98SIGB478 1/16 X 3 2.39 1.98SIGB479 3/32 X 3 2.51 2.08SIGB480 1/8 X 3 2.63 2.18SIGB481 3/16 X 3 2.87 2.38SIGB482 1/4 X 3 3.30 2.74SIGB483 3/8 X 3 4.50 3.74

VERY HARD - 36" Length

RETAIL MAP

SIGB493 1/16 X 3 1.62 1.34SIGB494 3/32 X 3 1.98 1.64SIGB495 1/8 X 3 2.34 1.94SIGB496 3/16 X 3 2.87 2.38SIGB497 1/4 X 3 3.23 2.68SIGB498 3/8 X 3 5.03 4.17

SPECIAL SHAPES

TRIANGLE - 36" LengthRETAIL MAP

SIGB416 1/4 X 1/4 0.88 0.73SIGB417 3/8 X 3/8 0.96 0.80SIGB418 1/2 X 1/2 1.90 1.58SIGB419 3/4 X 3/4 1.70 1.41SIGB420 1 X 1 3.70 3.07

LEADING EDGE - 36" LengthRETAIL MAP

SIGB085 1/2 X 3/8 2.00 1.66SIGB086 3/4 X 5/8 3.25 2.70SIGB087 1 X 3/4 3.95 3.28

SIGB282 2 X 4 3.70 3.07SIGB283 3 X 4 7.55 6.27SIGB286 1 X 6 3.83 3.18SIGB287 1-1/2 X 6 5.03 4.17SIGB288 2 X 6 5.99 4.97SIGB289 3 X 6 10.19 8.46

BLOCKS - 12" Length

RETAIL MAP

SIGB299 1 X 1 1.31 1.09SIGB300 1/2 X 2 1.55 1.29SIGB301 3/4 X 2 1.79 1.49SIGB302 1 X 2 2.40 1.99SIGB303 1-1/2 X 2 3.11 2.58SIGB304 2 X 2 3.40 2.82SIGB305 1/2 X 3 1.98 1.64SIGB306 3/4 X 3 2.87 2.38SIGB307 1 X 3 3.32 2.76SIGB308 1-1/2 X 3 5.51 4.57SIGB309 2 X 3 5.40 4.48SIGB310 3 X 3 10.40 8.63SIGB311 1/2 X 4 2.87 2.38SIGB312 3/4 X 4 3.59 2.98SIGB313 1 X 4 4.70 3.90SIGB314 1-1/2 X 4 6.40 5.31SIGB315 2 X 4 7.10 5.89SIGB316 3 X 4 13.00 10.79SIGB317 1/2 X 6 4.07 3.38SIGB318 3/4 X 6 5.03 4.17SIGB319 1 X 6 6.95 5.77SIGB320 1-1/2 X 6 8.15 6.76SIGB321 2 X 6 14.15 11.74SIGB322 3 X 6 20.39 16.92

BLOCKS - 24" Length

RETAIL MAP

SIGB354 1 X 1 2.63 2.18SIGB355 1 X 2 4.50 3.74SIGB356 2 X 2 7.91 6.57SIGB357 1/2 X 3 4.79 3.98SIGB358 1 X 3 6.83 5.67SIGB359 2 X 3 11.99 9.95SIGB360 3 X 3 18.47 15.33SIGB361 1 X 4 8.39 6.96SIGB362 2 X 4 15.59 12.94SIGB363 3 X 4 23.99 19.91SIGB364 1 X 6 13.79 11.45SIGB365 2 X 6 22.79 18.92SIGB366 3 X 6 32.39 26.88

SELECT GRADE SHEETS

CONTEST - 36" LengthVery Light 4 - 6 lb. Stock

RETAIL MAP

SIGB454 1/32 X 3 2.88 2.39SIGB455 1/16 X 3 3.00 2.49SIGB456 3/32 X 3 2.96 2.46SIGB457 1/8 X 3 3.36 2.79

3

TRAILING EDGE - 36" LengthRETAIL MAP

SIGB097 1/8 X 1/2 0.87 0.72SIGB098 3/16 X 3/4 0.95 0.79SIGB099 1/4 X 1 1.19 0.99SIGB100 5/16 X 1-1/4 1.43 1.19SIGB101 3/8 X 1-1/2 1.89 1.57

AILERON & ELEVATOR STOCK36" Length

RETAIL MAP

SIGB441 1/4 X 1 1.74 1.44SIGB442 3/8 X 1 3.66 3.04SIGB443 1/4 X 2 2.75 2.28SIGB444 3/8 X 2 3.03 2.51

TAPERED CUT SHEETS36" Length

Full width taper from 1/4" thick at oneedge to 1/8" thick at the other edge.

RETAIL MAP

SIGB430 1/4 X 3 3.20 2.66SIGB431 1/4 X 4 4.20 3.49

AIRFOIL SHAPED SHEETS36” Length

RETAIL MAP

SIGB111 3/16 X 3 X 36 3.18 2.64SIGB112 1/4 X 3 X 36 3.95 3.28SIGB113 1/4 X 4 X 36 4.86 4.03

BALSA BUNDLE DEALS

BALSA WOOD ASSORTMENTA 1-3/4" x 5" x 18" pack of miscellaneoussize balsa sheets - 1/32" to1/4" thick X 2"& 3" wide X 18" long. Plus a stick assort-ment. All top grade wood. Great value!

RETAIL MAP

SIGB600 15.83 13.14

BAG OF BALSAA large bag of assorted sheets, blocks &sticks. Cutoffs and second grade. Alluseful pieces for the right hobby project.Bag dimensions: 3” x 6” x 12”

RETAIL MAP

SIGB524 8.42 6.99

3" SHEET BUNDLEAn assortment of 3" wide x 36" long balsasheets, varying thickness. Second grade- some sheets will have slight imperfec-tions. Bundle measures 3" X 3" X 36".

RETAIL MAP

SIGB700 7.22 5.99

4" SHEET BUNDLEAn assortment of 4" wide x 36" long balsa sheets, varying thickness. Second grade- some sheets will have slight imperfec-tions. Bundle measures 3" X 4" X 36".

RETAIL MAP

SIGB702 8.42 6.99

STICKS & MOREA handy assortment of 36" long balsasticks. Lots of useful sizes of randomthickness & width. Second grade - somesticks will be bowed. Bundle measuresappoximately 2-1/2” dia. X 36” long.

RETAIL MAP

SIGB643 6.00 4.99

ODDS & ENDSA 2" x 3" x 18" pack of assorted size balsasheets & sticks. A low cost source ofsmall parts for the modelers. Perfect forcrafts or any hobbyist who is looking forvalue. Second grade - some pieces willhave small imperfections.

RETAIL MAP

SIGB534 7.11 5.90

SPECIAL SELECTION OF SIG BALSASpecial selection of balsa sheets for weight or grain type is available on a limited basis, depending on our supply at the time of your order.

Special selection of balsa sheets for WEIGHT is available in SOFT, MEDIUM, or HARD categories. The softer wood will be lighter in

weight; the harder wood will be heavier. Standard categories of balsa weight in the hobby industry is as follows:

SOFT = 6 to 9 lbs. per cu. ft. MEDIUM = 9 to 12 lbs. per cu. ft. HARD = 12 to 16 lbs. per cu. ft.

Balsa sheets can also be specially selected for A-GRAIN or C-GRAIN types. Description of balsa sheet grain types is in the back of this

catalog. Standard SIG balsa sheets (not special select) is random A, B, and C grain (mostly B-GRAIN, the most common type).

Special selection for weight or grain type is very time consuming and requires an additional fee:

Fee for Grain Selection: $0.25 per sheet

Fee for Weight Selection: $0.35 per sheet

4

1/32” THICK 3-PLY BIRCHRETAIL MAP

SIGPW001 6 X 12 2.80 2.32SIGPW002 12 X 12 5.17 4.29SIGPW003 12 X 24 10.10 8.38SIGPW004 12 X 48 19.70 16.35





1/8” THICK 5-PLY BIRCH RETAIL MAP


SIG PLYWOODSIG Aircraft Grade Plywood is the finest quality plywood available for model building. Imported from Finland andItaly, the plywood is actually produced in metric thicknesses (millimeters), which have been converted to the near-est inch dimensions for our use. Due to the nature of thin plywood sheets, it is impossible for us to guaranteethat every sheet will be perfectly flat and straight. In most cases, plywood parts cut from these sheets can easilybe straightened as they are glued into the model structure.

SIG “LITE-PLY”(c) PLYWOOD

Light weight Italian Poplar plywood foruse where greater strength is desiredover balsa, but regular birch plywood istoo heavy. About half the weight of ourregular birch plywood. Excellent for forfuselage sides, formers, wing ribs, cabinfloors, servo compartments, etc.

1/8” THICK LITE-PLY(c)

RETAIL MAP

SIGPW064 12 X 12 2.50 2.08

SIGPW065 12 X 24 4.60 3.82

SIGPW066 12 X 36 7.70 6.39

SIGPW067 12 X 48 9.50 7.89

1/4” THICK LITE-PLY(c)

RETAIL MAP

SIGPW068 12 X 12 4.70 3.90

SIGPW069 12 X 24 9.20 7.64

SIGPW070 12 X 36 13.30 11.04

SIGPW071 12 X 48 17.60 14.61






SIGPW021 6 X 12 3.05 2.53SIGPW022 12 X 12 5.80 4.81SIGPW023 12 X 24 11.10 9.21SIGPW024 12 X 4Y 22.00 18.26

1/64” THICK 3-PLY WINGSKINSRemarkable product consisting of 3 paperthin birch veneers laminated together withwaterproof glue. Popular for sheetingfoam core wings on airplanes wherestrength and toughness are more impor-tant than a very slight weight gain whencompared to 1/6” thick balsa wing sheet-ing. Also useful on many R/C boats.

RETAIL MAP

SIGPW035 12 X 12 8.55 7.10

SIGPW036 12 X 24 16.80 13.94

SIGPW037 12 X 48 33.20 27.56

SIGPW038 24 X 48 65.80 54.61

HARDWOOD DOWELS36 in. Length

RETAIL MAP

SIGBD026 1/8 dia. 0.44 0.37

SIGBD028 3/16 dia. 0.45 0.37

SIGBD029 1/4 dia. 0.53 0.44

SIGBD030 5/16 dia. 0.85 0.71

SIGBD031 3/8 dia. 1.09 0.90

SIGBD032 7/16 dia. 1.40 1.16

SIGBD033 1/2 dia. 1.82 1.51

SIGBD034 5/8 dia. 2.95 2.45

SIGBD035 3/4 dia. 3.90 3.24

Selected White Birch Dowels. Many uses

for building model airplanes, boats, archi-

tectural, landscaping, and other hobby-

craft projects. Strong, straight and

smooth.

12 in. LengthRETAIL MAP

SIGBD008 7/16 dia. 0.35 0.29

SIGBD010 5/8 dia. 0.55 0.46

SIGBD011 3/4 dia. 0.79 0.66Hardwood Birch Dowels

5

SIG BASSWOODBasswood is a native North American hardwood with fine grain and very consistent density. Easy to cut and easyto sand, basswood is ideal for many hobby and craft projects. SIG cuts only the highest quality clear basswoodfrom the forests of the northern United States and Canada. Basswood's straight grain makes it ideal for wingspars, longerons, and numerous other model airplane parts where additional strength is needed. Also the woodof choice for wood carvers. Good acoustic properties also make basswood popular for electric guitar bodies.Basswood can be stained or painted using any common type of wood finish.

STICKS - 24” LengthRETAIL MAP

SIGBA002 1/32 X 1/8 0.17 0.14

SIGBA003 1/32 X 3/16 0.21 0.17

SIGBA001 1/32 X 1/4 0.22 0.18

SIGBA004 1/16 X 1/16 0.16 0.13

SIGBA005 1/16 X 3/32 0.17 0.14

SIGBA006 1/16 X 1/8 0.20 0.16

SIGBA007 1/16 X 3/16 0.22 0.18

SIGBA008 1/16 X 1/4 0.28 0.23

SIGBA009 1/16 X 1/2 0.46 0.38

SIGBA111 1/16 X 1 1.05 0.87

SIGBA010 3/32 X 3/32 0.20 0.16

SIGBA011 3/32 X 1/4 0.29 0.24

SIGBA112 3/32 X 1 0.93 0.77

SIGBA012 1/8 X 1/8 0.21 0.17

SIGBA013 1/8 X 3/16 0.25 0.21

SIGBA014 1/8 X 1/4 0.32 0.26

SIGBA015 1/8 X 1/2 0.65 0.54

SIGBA113 1/8 X 1 1.02 0.84

SIGBA016 5/32 X 5/32 0.33 0.28

SIGBA017 3/16 X 3/16 0.29 0.24

SIGBA018 3/16 X 3/8 0.58 0.48

SIGBA019 3/16 X 1/2 0.70 0.58

SIGBA361 3/16 X 3/4 1.00 0.83

SIGBA114 3/16 X 1 1.29 1.07

SIGBA020 1/4 X 1/4 0.49 0.40

SIGBA021 1/4 X 3/8 0.60 0.50

SIGBA022 1/4 X 1/2 0.84 0.70

SIGBA115 1/4 X 1 1.48 1.22

SIGBA023 5/16 X 5/16 0.60 0.50

SIGBA024 3/8 X 3/8 0.81 0.67

SIGBA025 1/2 X 1/2 1.34 1.11


SIGBA301 1/16 X 1/8 0.35 0.29

SIGBA302 1/16 X 3/16 0.37 0.31

SIGBA303 1/16 X 1/4 0.42 0.35

SIGBA304 3/32 X 3/32 0.42 0.35

SIGBA305 3/32 X 1/8 0.44 0.36

SIGBA306 3/32 X 3/16 0.45 0.37

SIGBA307 3/32 X 1/4 0.46 0.38

SIGBA308 1/8 X 1/8 0.35 0.29

SIGBA309 1/8 X 3/16 0.43 0.35

SIGBA141 1/32 X 4 1.68 1.39

SIGBA142 1/16 X 4 1.72 1.42

SIGBA143 3/32 X 4 1.79 1.48

SIGBA144 1/8 X 4 2.04 1.69

SIGBA145 3/16 X 4 2.35 1.95

SIGBA146 1/4 X 4 2.85 2.36

STICK ASSORTMENTA handy assortment of 24" long bass-wood sticks. Lots of useful sizes of ran-dom thickness & width. Second grade,some sticks may have blemishes. Bundlemeasures appoximately 1-1/2” X 2” X 24”.

RETAIL MAP

SIGBA226 3.15 2.61

BAG OF BLOCKSA large bag of assorted size basswoodblocks. All useful pieces for the righthobby project. Cutoffs and second grade.Bag dimensions: 3” x 6” x 12”

RETAIL MAP

SIGBA250 11.99 9.95

GROOVED LANDING GEAR MOUNTSRETAIL MAP

SIGSH655 (2 per pkg.) 2.99 2.49

5/16" X 5/8" X 6” with 1/8" sq. groove

SIGSH125 (2 per pkg.) 2.99 2.49

3/8" X 3/4" X 6” with 5/32" sq. groove

SIGSH656 (2 per pkg.) 3.23 2.69

1/2" X 1" X 6” with 3/16" sq. groove

SIGBA310 1/8 X 1/4 0.50 0.42

SIGBA322 1/8 X 5/16 0.60 0.50

SIGBA311 1/8 X 3/8 0.56 0.46

SIGBA312 1/8 X 1/2 0.70 0.58

SIGBA313 1/8 X 3/4 0.95 0.79

SIGBA314 3/16 X 3/16 0.50 0.41

SIGBA315 3/16 X 1/4 0.56 0.46

SIGBA316 3/16 X 3/8 0.64 0.53

SIGBA317 3/16 X 1/2 0.77 0.64

SIGBA318 1/4 X 1/4 0.80 0.66

SIGBA319 1/4 X 3/8 0.84 0.69

SIGBA320 1/4 X 1/2 0.98 0.81

SIGBA321 3/8 X 3/8 1.05 0.87


SIGBA331 3/32 X 3/32 0.50 0.42

SIGBA332 3/32 X 1/8 0.52 0.43

SIGBA333 3/32 X 3/16 0.53 0.44

SIGBA334 3/32 X 1/4 0.65 0.54

SIGBA335 1/8 X 1/8 0.53 0.44

SIGBA336 1/8 X 3/16 0.56 0.46

SIGBA337 1/8 X 1/4 0.64 0.53

SIGBA338 1/8 X 3/8 0.78 0.64

SIGBA339 1/8 X 1/2 0.84 0.69

SIGBA340 1/8 X 3/4 0.99 0.82

SIGBA341 3/16 X 3/16 0.56 0.46

SIGBA342 3/16 X 1/4 0.70 0.58

SIGBA343 3/16 X 3/8 0.83 0.69

SIGBA344 3/16 X 1/2 1.05 0.87

SIGBA345 1/4 X 1/4 0.92 0.76

SIGBA346 1/4 X 3/8 1.11 0.92

SIGBA347 1/4 X 1/2 1.33 1.10

SIGBA348 3/8 X 3/8 1.34 1.11

SHEETS - 24” LengthRETAIL MAP

SIGBA131 1/32 X 3 0.99 0.82

SIGBA132 1/16 X 3 1.07 0.88

SIGBA133 3/32 X 3 1.22 1.01

SIGBA134 1/8 X 3 1.43 1.18

SIGBA135 3/16 X 3 1.63 1.35

SIGBA136 1/4 X 3 1.84 1.53

SIGBA137 3/8 X 3 2.62 2.17

SIGBA138 1/2 X 3 4.21 3.49

6

MAPLE MOTOR MOUNTS

Cut From Rock Hard Maple

Strongest Wood For Its Weight

Resists Splitting

Low Oil Absorption

ROCK HARD MAPLE has been the woodof choice for beam style motor mounts inmodel airplanes for decades. No otherwood can match it. These are the mosteconomical mounts you can buy. Maple

mounts add incredible strength to amodel when they are extended back be-hind the firewall into the fuselage. SIGMAPLE MOTOR MOUNTS are cut fromdense, rock hard maple - one of thestrongest woods for its weight available.


SIGMM001 3/8 X 3/8 2.39 1.99SIGMM002 3/8 X 1/2 2.39 1.99SIGMM003 3/8 X 3/4 2.39 1.99


SIGMM004 1/2 X 5/8 3.83 3.19

THREADED HARDWOOD BLOCKS

Cut from rock hard maple, these 3/8” x3/4” x 1” blocks are designed to be gluedpermanently into your fuselage to providehard points for mounting a removablewing or landing gear. Drilled and tappedfor the most common wing bolt sizes.2 blocks per package

RETAIL MAP

SIGSH218 1/4-20 thread 1.43 1.19SIGSH219 8-32 thread 2.51 2.09SIGSH592 10-32 thread 2.39 1.99

MISC. WOOD PARTS

SIG - THE MOST FAMOUS NAME IN BALSA!Like most kids who grew up in the 1920s and '30s, Glen Sigafoose was an avid builder and flyer of model airplanes. His interest in airplanes was

hereditary. His father Arthur Sigafoose was an Iowa aviation pioneer who flew hang gliders as early as 1910. Glen's first model airplanes were

made of bamboo and tissue. He did not see his first piece of balsa wood until the early 1930s. During his high school days Glen developed

several model airplanes which he sold through small ads in model magazines. He also became an avid motorcyle rider and mechanic.

Fast forward to the late 1940s when Glen was working as a printer / linotype operator / maintenance man in the local newspaper office. Glen and

his wife Hazel, who also worked at the newspaper office, operated their own side business selling and servicing Indian motorcycles. Their matched

pair of Indian Chief motorcycles were their only form of transportation year round. They didn't own a car until years later.

In addition to the motorcycles, both Glen and Hazel loved to build model airplanes of their own design. Without a hobby shop near them, they

were frustrated that balsa wood sheets and sticks could not be purchased by mail. They guessed that there must be many other builders in small

towns without hobby shops facing the same problem. So they purchased 120 board feet of raw balsa wood planks and began cutting it in their

basement workshop into the sizes used by model builders. They took out an ad in Model Airplane News magazine, offering free information about

their cut balsa wood and were surprised when they got no response. After thinking it over, a second ad was taken out offering the same information

for the price of a dime. Then the requests for the balsa began to come in. After five years of working nights and weekends, Glen and Hazel were

able to buy a building and quit their day jobs at the local newspaper. That was the birth of Sig Mfg. Co., the most famous name in balsa.

Vintage SIG ad that appeared in Model Airplane News magazine November 1966.

7

Model airplanes are no different than any other type of flying machine,

large or small - THE LIGHTER IT IS BUILT, THE BETTER IT WILL FLY!

With that in mind, it is easy to understand why balsa wood has been the

standard material for model airplane construction since it first became

readily available in the U.S. in the late 1920s. Its outstanding strength-

to-weight ratio enables hobbyists to construct durable models that fly in

a totally realistic manner. Balsa also absorbs shock and vibration well

and can be easily cut, shaped, and glued with simple hand tools.

WHERE DOES BALSA WOOD COME FROM? Balsa trees grow natu-

rally in the humid rain forests of Central and South America. Its natural

range extends south from Guatemala, through Central America, to the

north and west coast of South America as far as Bolivia. However, the

small country of Ecuador, on the western coast of South America, is the

primary source of model aircraft grade balsa in the world. Balsa needs a

warm climate with plenty of rainfall and good drainage. For that reason,

the best stands of balsa usually appear on the high ground between trop-

ical rivers. Ecuador has the ideal geography and climate for growing balsa

trees. The scientific name for balsa wood is ochroma lagopus. The word

balsa itself is Spanish meaning raft, in reference to its excellent floatation

qualities. In Ecuador it is known as Soya, meaning buoy.

HOW DOES BALSA WOOD GROW? There is no such thing as entire

forests of balsa trees. They grow singly or in very small, widely scattered

groups in the jungle. For hundreds of years, balsa was actually consid-

ered a weed tree. They reproduce by growing hundreds of long seed

pods, which eventually open up and, with the help of the wind, scatter

thousands of new seeds over a large area of the jungle. Each seed is air-

borne on its own small wisp of down, similar to the way dandelion seeds

One year old balsa tree.

spread. The seeds eventually fall to the ground and are covered by the

litter of the jungle. There they lay and accumulate until one day there is

an opening in the jungle canopy large enough for the sun's rays to strike

the jungle floor and start the seeds growing. Wherever there was an

opening, made either by a farmer or by another tree dying, balsa will

spring up as thick as grass. A farmer is often hard put to keep his food

plot clear of balsa. As the new balsa trees grow, the strongest will become

predominate and the weaker trees will die.

A stand of young balsa trees.

HOW LONG DOES IT TAKE A BALSA TREE TO GROW? Balsa treesgrow very rapidly (like all pesky weeds). Six months after germination,the tree is about 1-1/2 inches in diameter and 10-12 feet tall! In 6 to 10years the tree is ready for cutting, having reached a height of 60 to 90feet tall and a diameter of 12 to 45 inches. If left to continue growing, thenew wood being grown on the outside layers becomes very hard and thetree begins to rot in the center. Unharvested, a balsa tree may grow to adiameter of 6 feet or more, but very little usable lumber can be obtainedfrom a tree of this size. The balsa leaf is similar in shape to a grape leaf,

only a lot bigger. When the tree is young, these leaves measure as much

as four feet across. They become progressively smaller as the tree grows

Balsa tree leaves.

8

older, until they are about 8-10 inches across. Balsa is one of the few

trees in the jungle which has a simple leaf shape. This fact alone makes

the balsa tree stand out in the jungle.

THE PERFECT NURSE! Nature designed the balsa tree to be a "nurse

tree" which would protect the slower-growing species of trees from the

scorching jungle sun during their critical early years. For instance, in an

area of the jungle that has been ravaged by a tropical storm or other nat-

ural disaster, the balsa trees will quickly sprout and begin to shoot up to

impressive heights in a very short time. Their fast growth, and the extra

large leaves they have in their early years, provide shade to the young

seedlings of the slower-growing forest giants. By the time the seedlings

are established enough to take care of themselves, the balsa tree is be-

ginning to die. The balsa tree's rapid growth, fast spreading crown of first

very large and gradually smaller leaves, and it's relatively short life span

were intended to make it the "perfect nurse" in the jungle ecosystem.

Nature’s “Nurse Tree”.

HOW ARE BALSA TREES HARVESTED? While nature intended the

balsa tree to be a short lived nursemaid, mankind eventually discovered

that it was an extremely useful resource. The real start of the balsa busi-

ness was during World War I, when the allies were in need of a plentiful

substitute for cork. The only drawback to using balsa was, and still is, the

backbreaking work that is necessary to get it out of the jungle. Because

of the way the individual balsa trees are scattered throughout the jungles,

it has never been possible to use mass production logging procedures

and equipment. The best way to log balsa trees is to go back to the meth-

ods of Paul Bunyan - cut them down with an axe or saw, haul them to the

nearest river by ox team, tie them together into rafts, and then float the

rafts of balsa logs down the river to the saw mill.

Raw balsa logs at the sawmill.

At the saw mill the raw balsa is first rough cut into large boards, then care-

fully kiln dried, and finally packed into bales for shipment to the U.S. via

ocean freighter. Final cutting and finishing of our model aircraft balsa is

done right here at the SIG factory. As a result of the balsa tree's fast

growth cycle, both the quality and lightness of the lumber obtained from

a balsa tree can vary enormously depending upon the tree's age at the

time of cutting.

Rough cut balsa boards at the sawmill.

WHY IS BALSA WOOD SO LIGHT? The secret to balsa wood's light-

ness can only be seen with a microscope. The cells are big and very thin

walled, so that the ratio of solid matter to open space is as small as pos-

sible. Most woods have gobs of heavy, plastic-like cement, called lignin,

holding the cells together. In balsa, lignin is at a minimum. Only about

40% of the volume of a piece of balsa is solid substance. To give a balsa

tree the strength it needs to stand in the jungle, nature pumps each balsa

cell full of water until they become rigid - like a car tire full of air. Green

balsa wood typically contains five times as much water by weight as it

has actual wood substance, compared to most hardwoods which contain

very little water in relation to wood substance. Green balsa wood must

therefore be carefully kiln dried to remove most of the water before it can

be sold. Kiln drying is a tedious two week process that carefully removes

the excess water until the moisture content is only 6%. Kiln drying also

kills any bacteria, fungi, and insects that may be in the raw balsa wood.

Balsa cell structure seen under a microscope.

HOW LIGHT IS KILN DRIED BALSA WOOD? Finished balsa wood,

like you find in model airplane kits, varies widely in weight. Balsa is oc-

casionally found weighing as little as 4 Ibs. per cu. ft. On the other hand,

you can also find balsa which will weigh 24 Ibs. or more per cu. ft. How-

ever, the general run of commercial balsa for model airplanes will weigh

between 6 pounds to 16 Ibs. per cu. ft. Eight to twelve pound balsa is

considered medium or average weight, and is the most plentiful. Six

pound or less is considered "contest grade", which is very rare and some-

times even impossible to obtain.

IS BALSA THE LIGHTEST WOOD IN THE WORLD? No! Most people

are surprised to hear that botanically, balsa wood is only about the third

or fourth lightest wood in the world. However, all the woods which are

lighter than balsa are terribly weak and unsuitable for any practical use.

The very lightest varieties don't really resemble wood at all, as we com-

9

monly think of it, but are more like a tree-like vegetable that grows in

rings, similar in texture to an onion. It is not until balsa is reached that

there is any sign of real strength combined with lightness. In fact, balsa

wood is often considered the strongest wood for its weight in the world.

Pound for pound it is stronger in some respects than pine, hickory, or

even oak (see chart below).

STRENGTH OF BALSA WOOD COMPARED TO OTHER WOODS

Weight Stiffness Bending Compression

Species Lbs./Cu. Ft. Strength Strength Strength

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

NOTE ABOUT CHART: The strength of balsa varies in direct relation to

its density or weight - the heavier the wood, the stronger it is. The

above chart was designed with 10 Ib./cu. ft. balsa as the median. In other

words, balsa at 10 Ibs./cu. ft. has been tested given a value of 100. The

other woods were then tested in the same way and given a figure that is

numerically in proportion. By comparing the relative strength figures in

the chart, it will be seen that balsa is as strong or stronger, pound for

pound, than most of the species shown.

SELECTING BALSA FOR MODEL BUILDING: Because of the nature

of balsa, two pieces of wood with the exact same dimensions may vary

quite a bit in weight. When you select the pieces you want for our project,

you should keep their final use in mind. Logically one should select the

lightest grades for the lightly stressed parts of the model (nose blocks,

wingtip blocks, fill-ins, etc.), and the heavier grades for important load

bearing parts of the structure (spars, fuselage stringers, etc.).

When describing the weight of balsa wood, the standard unit of measure

is POUNDS PER CUBIC FOOT (lbs./cu.ft).

To give you an idea how much common sizes of balsa can vary in weight

depending upon the density of raw stock it was cut from, the following

three charts have been developed. They show the actual weight in

ounces of each size piece when it is cut from 6, 8, 10, 12, 14, or 16 lb./cu.

ft. stock. For example, in the first chart for BALSA SHEETS we see that

a 1/16" x3" x 36" sheet cut from 10 lbs./cu. ft. stock will weigh approxi-

mately .625 ounces. The same size sheet cut from 14 Ibs./cu.ft. stock will

weigh about .875 ounces.

SIG Mfg. Co. has been producing model grade balsawood since 1951. In this early photo founder GlenSigafoose (left) inspects and grades finished balsa sheets.

10

A knife or razor blade will work well for cutting balsa sheets and sticks up

to 3/16" thick. Use a razor saw for sizes over thicker than 3/16". Always

keep replacement blades on hand - blades do wear out and a dull blade

can make it impossible to do a good job.

YOU WILL ALSO NEED SANDING BLOCKS: In addition to the cutting

tools, you will need an assortment of different size sanding blocks. These

are indispensable tools for model construction. You can buy ready-made

sanding blocks or make your own. The most often used general-purpose

sanding block in our model shop is made simply by wrapping a full 9" x

11" sheet of sandpaper around a 3/4" x3" x 11" hardwood or plywood

block. Use three screws along one edge to hold the overlapped ends of

the sandpaper in place. Use 80 grit garnet sandpaper on the block during

general construction.

COMMON MODELER'S TOOLS FOR CUTTING AND SHAPING

BALSA WOOD: Balsa is a very "friendly" wood to work with - light, soft,

and easily worked into so many things. You don't need heavy-duty power

saws and sanders like you would if working with a hardwood. In fact, even

with an extensive power shop at their disposal, the professional model

builders here at the SIG factory find that they still rely primarily on 4 or 5

simple hand tools for the majority of their work. If you are just starting out

in the model airplane hobby, here are the tools that they recommend that

you get:

11

Another handy sanding block to have can be made by gluing 80 grit gar-

net sandpaper onto a 24" or 36" long piece of aluminum channel stock.

Most hardware stores carry a rack of aluminum in various sizes and

shapes. This long sanding block is very helpful for shaping leading and

trailing edges, and other large pieces, accurately.

Last but not least, glue sandpaper onto different sizes of scrap plywood

sticks and round hardwood dowels. These are handy for working in tight

places and for careful shaping where a big sanding block is too hard to

control.

We like to use craft glue in a spray can (like 3M “77”® Spray Adhesive)

for gluing the sandpaper on our homemade sanding tools.

In selecting balsa sheets for use in your model, it is important to consider

the way the grain runs through the sheet as well as the weight of the

sheet. The grain direction actually controls the rigidity or flexibility of a

balsa sheet more than the density does. For example, if the sheet is cut

from the log so that the tree's annular rings run across the thickness of

the sheet (A-grain, tangent cut), then the sheet will be fairly flexible edge

to edge. In fact, after soaking in water some tangent cut sheets can be

completely rolled into a tube shape without splitting. If on the other hand

the sheet is cut with the annular rings running through the thickness of

the sheet (C-grain, quarter grain), the sheet will be very rigid edge to edge

and cannot be bent without splitting. When the grain direction is less

clearly defined (B-grain, random cut), the sheet will have intermediate

properties between A and C grain. Naturally, B-grain is the most common

and is suitable for most jobs. The point to bear in mind is that whenever

you come across pure A-grain or C-grain sheets, learn where to use them

to take best advantage of their special characteristics. The following chart

illustrates the 3 basic grain types for sheet balsa and lists the most ap-

propriate uses for each.

BALSA GRAIN ID. CHART - LEARN TO IDENTIFY ALL THREE GRAIN TYPES

A-GRAIN sheet balsa has long fibers that show up as long grain lines. It is very flexible

across the sheet and bends around curves easily. Also warps easily. Sometimes called

"tangent cut".

DO: Use for sheet covering rounded fuselages and wing leading edges, planking fuse-

lages, forming tubes, strong flexible spars, HL glider fuselages.

DON'T: Use for sheet balsa wings or tail surfaces, flat fuselage sides, ribs, or formers.

B-GRAIN sheet balsa has some of the qualities of both type A and type C. Grain lines

are shorter than type A, and it feels stiffer across the sheet. It is a general purpose sheet

and can be used for many jobs. Sometimes called "random cut".

DO: Use for flat fuselage sides, trailing edges, wing ribs, formers, planking gradual

curves, wing leading edge sheeting.

DON'T: Use where type A or type C will do a significantly better job.

C-GRAIN sheet balsa has a beautiful mottled appearance, it is very stiff across the sheet

and splits easily. But when used properly, it helps to build the lightest, strongest models.

Most warp resistant type. Sometimes called "quarter grain".

DO: Use for sheet balsa wings and tails, flat fuselage sides, wing ribs, formers, trailing

edges. Best type for HL glider wings and tails.

DON'T: Use for curved planking, rounded fuselages, round tubes, HL glider fuselages,

or wing spars.

12 © 2012 SIG Mfg. Co. Inc.

Documents

manual for making toy planes