tinstafl is on the money.
citric acid is a particular threat to epoxy. it almost unique in that it attacks the strength of the glue.
this doesn't apply to resorcinol formaldehyde glue. that has different characteristics.
What I hope I have done is give people a route to the confidence needed for building a turbulent.
there are really only two hard things about building an aeroplane such as a turbulent, or any aeroplane for that matter.
Deciding to start the project.
Completing the project.
the rest of it is just technique.
I am still looking for some spar strength calculations I did some time ago so I have another post or two to make. be patient.