Kelsey_B

Since most kits are gone, I have started duplicating the kits I have. I would like to know what the difference between hardwood and basswood is. You can buy maple and basswood sticks from Lone-Star. You can also buy sheets of basswood but I don't know where you use a sheet of this stuff. Can basswood be used where plans indicate to use hardwood?

Edwin

My Feedback: (2)

I'm doing the same thing. Mostly making templates from the kits to use with the plans. I use basswood in areas like spars and so on or someplace that needs dense wood for screws. I dont use it in high strength areas like retract mounts. Havent used any basswood ply. I just use regular 5 and 7 ply plywood. Contrary to what some do, I'll use light ply in places like a big fuse former instead of laminated balsa.
Edwin

Dr1Driver

Bass IS "hardwood", but one of the softer hardwoods. Another commom hardwood you see in our hobby is spruce. Much harder. In the model furniture/craft/doll house sections you might see mahogany, oak, redwood, etc. These are not generally suitable for our use.

Dr.1

PS Did you know balsa is considered a hardwood? From Wikipedia:

Balsa (Ochroma pyramidale, synonym O. lagopus) is a large, fast-growing tree to 30 m tall, native from tropical South America north to southern Mexico. It is evergreen, or dry-season deciduous if the dry season is long, with large (30–50 cm) weakly palmately lobed leaves. The name balsa derives from Spanish for a raft.

The timber is very soft and light with a coarse open grain. The density of dry balsa wood ranges from 100–200 kg/m³, with a typical density of about 140 kg/m³ (about one third the density of other kinds of hard wood). This makes it a very popular material for model building and buoyancy materials (lifebelts, etc.), and was famously used by Thor Heyerdahl in his raft Kon-Tiki. It is also a very popular material to use when making wooden crankbaits for fishing, as it is low density but high in strength. Balsa wood is used to make very light, stiff structures in model bridge tests and for the construction of light wooden aeroplanes, most famously the World War II de Havilland Mosquito. It also is used in the Chevrolet Corvette bodies tub. In table tennis blades, a balsa layer is typically sandwiched between two pieces of thin plywood.

Despite being very soft, balsa is classified as a hardwood, the softest commercial hardwood.

Rodney

Just an aside, but Balsa is also a hardwood if you go by the definitions of hardwood. Spruce and Fir are softwoods by the same definition. If it has needles instead of leaves it is softwood, if leaves instead of needles it is a hardwood. Also balsa can be found so soft you can put your fingers thru it or so hard it is difficult to cut with a knife or drive a nail through, sometimes on the same tree. Balsa is a very interesting and unusual plant.

Dr1Driver

Kelsey_B

I have another question.

I'm looking at a set of drawings that call for 1/4 x 1/2 x 30 "hard" balsa wing spars. Can you specify hard balsa when ordering, or would basswood be better to use? I need some expert opinions here.

Keith

Dr1Driver

You can sometimes specify "contest" balsa. That's extra light wood. Otherwise, you usually take what you get. You can go to your local balsa store. A hobby shop, Michael's, or Hobby Lobby should have what you need. "Hard" balsa will be slightly grey and have a pronounced grain. It wom't flex much. In this case, you can also substitute bass.

Dr.1

BMatthews

Balsa is graded by it's density. Less than 6 lb/cu inch is considered as Contest grade. 6 to 8 as medium. 8 to 10 as medium hard and over 10 as hard. But when you order your best bet is to ask for the density range you want. The actual names of the grades may vary from dealer to dealer but density nails it down for what you want.

Maple is more for engine mounts and stuff like that. Bass wood is more a substitute for spruce wing spars and the like. The sheets of basswood are probably intended more for scale doll house or miniature furniture hobbyists. Or maybe the zealots that prefer to rip their own wing spars from sheet they can study for grain runout and the like.

scratchonly

I find hard balsa very hard to find; this is due, I believe to the fast growth trees they are now growing. I use basswood from lonestar because I like the tight grain and slight flex it offers over spruce. You can straighten basswood by holding it up against the grain at one end and running a hot iron slowly down the stick. Be gentle so you don't break it. Hope this helps.

tucker1865

My Feedback: (6)

Most kit manufactuers in the earlier days use balsa that was harder than most of what you see now days....The Faster the tree grows the softer the wood will be and the grain pattern will be wider. It has to do (in most cases) with the growing season. Pacific Coast Maple is softer than Maple grown in the east due a more moderate climate, and longer growing season. Most kit manufactuers substitute Basswood for Spruce because it is becoming rare and expensive. You can buy spruce here http://www.aircraftspruce.com/catalo...s/capstrip.php, and forget the basswood all together. And yes, Balsa is a Hardwood (has to do with its leaves) Maple does not glue as well as some other hardwoods due to it's density, there is little open grain to allow for bite. Maple's strength is overkill. I think you could use Poplar or even Mahogany where it calls for maple (usually landing gear blocks etc.), and both glue better than Maple.