Hood frame/support glue?
 

I have an second-hand hood and the frame/support/skeleton has seperated from the hood.

Is there a certain glue/compound I can use to reattach it? Im thinking of something that can be applied with a caulk gun.

any suggestions what will withstand the underhood heat without melting?

I would think you could use seam sealer. you should be able to get it at any automotive paint supply.

...I would go to a place that would have it and ask them what they think you should use. I'm sure they would have all kinds of 2 part epoxy as well.

it might make a differance if your hood is metal, fiberglass, or carbon fiber.