The main frame has quite a brownish color. Less brown are the closed wings (more normal "yellowish", but still slightly brownish). The tail parts, gear doors, flaps, ailerons etc have the "modern" normal color (yellowish, almost greenish).

 

Owner say brownish color depends on the different epoxy type used back in 1990, and that kit has been stored indoor all times, etc. I need top know whether epoxy type is the only reason. Or if the chance, with this color description, is high that there has been sun exposure during some week/month period in all of all those years.

 

Comments most appreciated. I have pictures.

Magnus,

 

I built the structural parts of my 320 between 1989 and 1993,  During that time, Safe-T-Y Poxy II was THE epoxy used in construction along with a 3-M industrial cement (fuel proof) for all work.

 

The safetypoxy II can (and will) turn a rich brown color - and is fine as long as it appears clear (translucent) as opposed to muddy.  The benefit is (and was) that voids stand out like a tan thumb when used with the glass (not carbon) prevalent at that time. Some of the reason that the hardener turns brown is interaction with the valve in the proportional pump and some is age.

 

Another benefit of  'Poxy II" was its about 2 hours of working time - enough time for big and complex lay-ups.  The downer was that micro so prepared required 2 days before it could be sanded.  Boil-off was unheard of.

 

Fast-built used to mean that you finished in less than five years.  It took me seven (Just like the 11 years for a BS).

 

Anyway, see my follow on msg on Prep!

 

And Ordinary Composite Materials.