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Norway Spruce in aircraft construction

Posted By:
Charles Hinton
13
Posts
1
#1 Posted: 3/31/2011 10:39:13

I'm wondering if anyone has information about using Norway Spruce in aircraft.  We have a lot available locally that was imported from Germany.  It's labeled "N SPR GER" and the company that imported it says that it's "Nordic Spruce" which I assume must be what we call Norway Spruce.  Anyway it's very nice light fine-grained wood and the capstrip I cut is as strong as Douglas Fir.  But I can't find any reference to using it in aircraft.  I wonder what the Europeans use?



Clarke Tate
Vintage Aircraft Association MemberHomebuilder or Craftsman
75
Posts
9
#2 Posted: 4/1/2011 13:45:08 Modified: 4/1/2011 14:32:56

 Hello Charles,

The short answer is possibly, subject to testing and your personal decision. In general it appears the strength is slightly less than that of Sitka Spruce although there seems to be a strength value overlap. The upper limit of Norway Spruce and lower strength values of Sitka so, don't quote me on this and I take no responsibility, it appears using this would be alright. If the grain is nice it would probably be good subject to testing.

In my quick check of Norway Spruce the Modulus of Elasticity (EM.).) appears to be between 6600 and 9100 Mpa.  That would be about 913,738 – 1.32 million pounds per square inch. This compares to The EM of Sitka spruce grown in the United States is 1.23 and 1.57 million pounds per square inch (psi) for green and dry wood, respectively. Sitka spruce from Canada has a EM of 1.37 and 1.63 million psi for green and dry wood, respectively (Haygreen and Bower, 1989 ). I would like to compare Modulus of Rupture  (MOR) but just don't have any more time to do that. It is a value of interest, for me it was the more tangible concern when testing that my Sitka Spruce was within tolerance for usage. I just haven't had the time to find that value for you of the Norway Spruce.

The EM seems to be highly dependent on where in the trunk the wood was taken. The bottom of a trunk appears to be lower in strength than the top in my quick scan of the papers on Norway Spruce.

Test a sample of both Sitka Spruce and the Norway Spruce and see for yourself.

I did a test on some on big box store whitewood from Canada and it tested at nearly the same level as my best Sitka Spruce. The big box store wood was clear, straight grain and really amazing actually. I couldn’t make myself use it though as my time is so valuable and the Sitka Spruce cost is minimal in comparison.

 A good way to test wood is over at Ron Wattaja’s Bowers Flybaby site.

 http://www.bowersflybaby.com/tech/testing_wood.pdf 

 My initial trials testing wood are on my building site.

 http://chiltondw-1.blogspot.com/2009_02_08_archive.html 

 Several papers on Norway Spruce have been added to my Google documents.

  Graded quality of 30-year-old Norway Spruce grown on agricultural and forest land 

  The Performance glue laminated beams manufactured from machine stress graded norwegian spruce 

 To translate test values use Wolframalpha.com for example 9100Mpa to Psi.

 

I have also added to my Google documents ANC-18 Design of Wood Aircraft Structures.

This may have some information of value in making a decision.

 

 

 

 

 

 

 

 

 



C Tate
Charles Hinton
13
Posts
1
#3 Posted: 4/2/2011 00:39:08

Clark,

Thanks very much.  That is information I can sure put to use.

Chuck



Clarke Tate
Vintage Aircraft Association MemberHomebuilder or Craftsman
75
Posts
9
#4 Posted: 4/2/2011 13:09:59 Modified: 4/2/2011 13:36:03

Hello Chuck,

I have created a chart comparing common woods used for construction of amatuer built aircraft. The chart shows Sitka Spruce, Douglas Fir, Hoop Pine (commonly used in Australia) and the Norway Spruce you asked about. Maybe some members from Europe have experience with this wood and will share with us!

 

Data derived from information on TheWoodExplorer.com

Chart created by Clarke Tate 2011 rev.1

This chart does not indicate a suitability for any usage, but is merely a comparison

 

This chart, Wood Properties for Amateur Aircraft Chart rev1, is also available on my Google documents,

 

 

 

 



Files Attachment(s):
Wood Properties for Amateur Aircraft Chart rev1 jpg.jpg (328246 bytes)
C Tate
Clarke Tate
Vintage Aircraft Association MemberHomebuilder or Craftsman
75
Posts
9
#5 Posted: 4/3/2011 10:24:06 Modified: 4/3/2011 12:05:46

 I have attached a screen shot of wood data sheets from MatWeb.com of Sitka Spruce, Douglas Fir and Norway Spruce. Hoop Pine data was not available from this source for comparison. This comparison information would seem to indicate that European Spruce (Norway Spruce) would be a suitable substitute for amateur aircraft building. The numbers regarding the flexural modulus of the Norway Spruce appear to actually be better than that of Sitka Spruce. I am not an engineer and I would still test the sample prior to actual usage.

 

Chuck where did you find this wood?

 

 



Files Attachment(s):
Comparing Sitka Spruce, Douglas Fir and Norway Spruce from Materials Web Sharp.jpg (428862 bytes)
C Tate