Can somebody direct me to a thread that will explain wood classes and their application. You see my question is. . . .

What kind of wood is best suited for
1) Spar
2) Firewall
3) Ribs
etc

Thanks

1) spruce/bass-wood/strong balsa.
2)ply (NOT lite ply)
3)balsa/lite ply

Balsa is sold as A-, B- and C- grain as well as a mix, if I remember right. Next time you're at your LHS, see if he has a Sig catalog. I think they explain it in there somewhere. Besides the grain orientation, there's density - weight per cubic foot or something.

Lite ply isn't much good for anything except formers.

(you've gotta love a guy with an online name of 'balsa') I agree with his posts entirely. The LHS will have aircraft plywood, spruce and balsa. If I had my druthers, I'd buy Sig balsa - it tends to be consistently of good quality. Midwest seems to have the greatest of range of wood types, including really nice spruce.

1) spruce.
2) birch plywood.
3) dense balsa or poplar (lite) ply.

1) you want to make sure the spruce is knot free with tigth consistent grain.

2) depending on the size of the plane, anywhere from 1/4" to 1/2" thick. The best birch plywood comes from finland.

3) I prefer lite-ply to dense balsa here...the poplar lite ply is about as light as the balsa, but much stronger. The best poplar ply you can get is "AB/AB model grade".

Mace Gill
The Aeroplane Works

But its still poplar, ie. the stuff they use in poor quality ARTF's.

Well, thats just my opinion.

Balsa

i thought they used mahogany for all airframe glued together with cement- not balsa cement, blue circle cement!!!!!!!!

gotta love those bad artf's - what a laugh.

can you please tell me where basswood, spruce and polplar is used.

ie polar is good for wing , fuse etc.

thanks

Poplar is good for nothing IMHO and as i have already said, spruce and bass-wood are used for spars and sometimes stringers on large scale aircraft.

poplar is fine for formers and ribs. It is as light as dense balsa and stronger. It can be a little harder to work with using your hobby knife. It is NOT structural.

Spruce and Bass are good for spars (I prefer clean, tight grained spruce).

Mace Gill
The Aeroplane Works

Then it has no use in my models! Sorry, but the formers in my models are structural. They prevent the sides from bowing and twisting as well as provide a place to attach the front and rear wing attachment plates.

Balsa is wonderful for ribs. All but the heaviest balsa is lighter than poplar ply, easier to work with, and plenty strong enough for the task at hand.

John

I meant not structural in the same way as Aircraft ply. There is nothing wrong with Balsa, it is easier to work with. I am merely explaining applications for poplar lite ply.

Mace Gill
The Aeroplane Works