Mark, I noticed on your web page that you laminated the spar caps with the
pieces one on top of the other as viewed with the spar standing vertically.
The plans don't really say, but a spruce list I have from Rand seems to
indicate that the pieces were intended to go side by side, as in the glue
joint going vertical with the spar in the normal orientation.  That is also
the way that the spars were made in the three KRs I have had.

I know that you thought about this before you did it and probably have some
good reasoning on deciding to do it this way.  Could you tell me what it
was.

Before anyone gets the idea that I am saying one way is right or wrong, that
is not what I meant at all.  I have seen spars in production planes
laminated in either direction.  For tall spar caps you normally see a
vertical glue line and for bent laminated spars you have no choice to go
horizontal.  The A.C. 43.13 states that laminated spars can be used in place
of solid spars without a reference to direction and a laminated spar should
be stronger than solid wood no matter what direction the glue lines are in.
I am just curious on this.

The only thing I wouldn't do is build a spar with a horizontal glue line
right where a bolt hole is going for the wing attach fitting.

Brian Kraut
Engineering Alternatives, Inc.
www.engalt.com


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