Are you concerned about the toxicity of the glues you used?
I was initially concerned about using glue and was thinking of a metal brace or something, until I had a closer look and realized that it was originally put together using glue.
That is when i sent an email to Marc at firewood (the maker of fw3 as far as i know) asking about the glue he uses, or at least what he would recommend. He recommended ca wood glue. I assume, therefore, that is what he uses (or similar?) And also the break was at the bottom where it was glued already, and where it does not get very hot.
I then thoroughly researched ca glue safety and it seems pretty safe, especially once cured, so i went ahead and used it. I also let it cure twice as long as necessary (48 hours) and after that i blew alot of air into the unit from all angles.
I couldn't smell any glue smell at all after all this, so don't have any major concern.
If you wanted to be extra sure, Gorilla glue has a "food safe" type of rating, or the medical stuff they use instead of stitches would be even safer (and more expensive) i assume, but my brother already had a number of types of ca glue lying around so we used the locktight version (as it said it was for wood too) If i had none already i would have bought Gorilla glue to use.
Finally, keep in mind i live outside USA so sending it back wasn't really an option for me.