Re: wing spars witc C grain at front?

From: ray_harlan <rbharlan_at_comcast.net>
Date: Mon, 09 May 2011 12:44:43 -0000

I was really implying that the wood is more consistent across the whole sheet.

Ray

--- In Indoor_Construction_at_yahoogroups.com, "Mark F1diddler" <f1diddler@...> wrote:
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> --- In Indoor_Construction_at_yahoogroups.com, "ray_harlan" <rbharlan@> wrote:
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> >The big reason for using A grain sheets is that they are much more consistent than C grain, since the whole sheet was grown over a short period of time and doesn't have effects from different seasons, as can C grain.>>
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> Good catch, Ray! However, considering how fast balsa trees grow, we are not talking different *seasons* here, but merely a few days difference. Consider a spar, just for round numbers, that is .030" X .060". The C faced spar might have grown in a period of 12 days, but the A faced spar may have grown in a period of 6 days.
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> (Online SIG data: "balsa trees are ready for harvest 6-10 years where could be from 12-45" diameter.") So, grabbing the middle number(28" diameter over 8 years, just for argument) would indicate average annual radius increase of 1.75", or about .005" per day.
> MB
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Received on Mon May 09 2011 - 05:44:49 CEST