From: highflyer <highflyer@alt.net>
Newsgroups: rec.aviation.homebuilt
Subject: Re: Wood- spruce vs bass
Date: Fri, 02 Oct 1998 15:29:53 -0500

Dreidjax wrote:

> Hi Jim,
> Clear fir would be a more suitable substitute for spruce. It's available
> locally in most places.
>
> Grading criterion is similiar to spruce. Verticle grain (sawn), at least 8
> annular rings per inch and a grain runout of no less than 1:15. Moisture
> content, well...as dry as you can get (works for me...I live in Florida).
>
> Iam building a pober Pixie and all the wood is clear fir. The spars may be as
> well, depending on what the "Big Houses" have to offer. If there's is not up to
> MY standards I'll be selecting my spars from "Home Depot". :-)
>
> They will, of course, be laminated.
>
> Check around...I think you'll find Clear fir to be a good value compared to
> spruce.
> By the way...what are you building?


The fir is more splintery than spruce and can be a little harder
to work up into nice structural shapes.  It is about 10% stronger
than Spruce, and a bit heavier as well.  Spruce has a slightly
better strength to weight ratio than Fir.  If you build using
dimensions for spruce using Fir  you will be both stronger and
heavier than the "as drawn" version.  That may or may not be
critical depending on the design.  There is a lot of fir in my
Pietenpol.  Less in my Cavalier.