Unbound message form add to rails for form message (append to listing)

I have a form for a troubleticket model, and I can create a new ticket with ease.

But, I want my edit (update) crud function to work a bit differently. I don’t want them editing the original text, so I want to include an unbound form for them to add additional notes.

Do I add this form and combine the previous message with this new message in the controller or can it be done in the view? (currently, I have all the form field hidden, so they can be passed along to the controller).