Well done! It is always  good advice when backed by research. Thanks.

-----Original Message----- 
From: Oscar Zuniga
Sent: Saturday, November 02, 2013 1:47 PM
To: krnet at list.krnet.org
Subject: KR> Post curing wings


Good information about post-curing.  Check the heat distortion temperature 
for the foam board that you're using if you decide to post-cure.  Some of 
the molded polystyrene boards (such as pink Owens-Corning Foamular; blue Dow 
Styrofoam) have heat distortion temperatures in the 100-105C range 
(210-220F), but others may be lower.  If the foam substrate gets into those 
temperatures, you could find that the piece that you're post-curing may take 
on some permanent distortion.

This topic has come up over the years when discussing the use of less 
reflective, generally darker paint colors on composite airplanes with a foam 
substrate... like the KR.  A darker airplane parked out in the sun can 
develop temperatures in the foam that can exceed the distortion temperature, 
which is one of the reasons that KRs have traditionally had white or light 
colored paint jobs.  Not saying that it will melt like Icarus' wings, but it 
could result in a droop, twist, or other distortion.

The urethane foams (such as Last-A-Foam) have much higher distortion 
temperatures than polystyrene board.

Oscar Zuniga
Medford, OR

_______________________________________________
Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search.
To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org
please see other KRnet info at http://www.krnet.org/info.html
see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change 
options 


Reply via email to