Balsageek

Ok I'm on my second scratch building project and I ran into a little problem. I know this probably sounds stupid, but can I substitute spruce main wing spars with basswood? The plans call for spruce but all I could find at BalsaUSA and Lonestar was basswood!

Thanks in advance,
Matt

cubfan

It all depends on what kind and size of plane it is. If it is a .40 or .60 size sport plane, high wing (i.e. cub type) I would not be afraid to at all. I have even used balsa. I have a 14 yr. old .40 size stick type plane that is scratch built with balsa spars and sheer webs half-way out the wing. The spars are 48" long 1/4" square. It is flat one piece no fiberglass in the center section. I fly this plane pretty rough cause it is my punch holes in the sky plane. Just rember KEEP IT LIGHT Cubfan

Gene Chernosky

My Feedback: (182)

Basswood is more elastic than spruce...i.e. spruce will shatter easier than basswood. Basswood is slightly heavier than spruce.

OK, the choice is yours.

ChuckAuger

My Feedback: (12)

If you want spruce, you can get it here...

http://www.superiorbalsa.com/

Rodney

If you have access to a table saw (or know of a friend who does) just go to the local lumber yard and pick out a nice straight grained piece of pine. you may have to look over quite a few boards to find one suitable, but then cut your own spars. I do this all the time for my big birds; pine is nearly as good as spruce and both spruce and pine are stronger than basswood by a slight amount. One note of caution, if you use hardwoods, don't use CA's as the acid in the hardwoods weakens the joint. You can overcome this to a degree by lightly dusting the joint with soda (the kind you use in the kitchen) before using the CA. I prefere the alphatic resins though, especially when working with hardwoods.

lparky

Go to this link for a good comparison of Bass Wood, Balsa, Spruce, etc.
I use Bass Wood from Lonestar or Balsa Usa.

Larry

http://www.mentornet.org/balsa.htm#anchor397363

bluesky123

My Feedback: (2)

Read this:
http://www.netexperts.cc/~lambertm/Wood/usdabook.html
A pretty comprehensive resource of wood properties, strength analysis of wooden structures, etc.
Hope this helps,
Boris