why does wood change colour in the rain?

 

I have a balcony constructed from cedarwood decking.   When the decking

was originally laid, about 3 years ago,  it had a wonderful lustrous
reddish-brown colour, which has gradually faded until now its usual
colour is a silver-grey.   But the odd thing is,  when it rains,  the
water seems to bring up the original vibrant colour, which stays until
the wood dries again, when it goes back to grey.   Does anyone have the

explanation for this phenomenon?   Might it be possible to retain the
original colour  even when the wood is dry - without using a stain?

Ken

 




Varnishing from new helps preserve any moisture already present in
the wood, which is what gives it its original colour. There is
also the question of bleaching by UV light, which may or may not
be a separate issue.

When unvarnished wood becomes wet, the wood swells up, and water gets
into the vessels on the suface* and mimics the effect of the original
moisture.

It might be possible to reproduce this effect by pressure injecting
the timber with super-thin varnish but this would be totally
uneconomical as compared with staining.

And wet clothes are also darker in colour of course. Although
quite what this has to do with wood I'm not sure.

michael adams

* but only to a limited extent, as the vessels are horizontal of
  course.

 



have a look at this
http://www.madsci.org/posts/archives/may99/926389846.Ch.r.html  

 



Oil maybe ??

Two American sites which might be of use....

http://www.cedar-deck.org/why_real_cedar/overview.htm
http://www.fairharbor.com/home_deck_faq.htm#Necessary

Jenny

 


JennyC wrote:

I think it's too late to regain the colour. Ken should have used it at
the beginning. We've constructed almost everything by ourselves in and
around our house. The thing to do now is enjoy the silver colour and
clean the decking with pressure water. We've used western red cedar on
one of our buildings (175 flats with exterior wood panelling and a
bridge). It's now all silver and is very beautiful. When it rains it
goes darker and once it's dry goes back to silver.