Typically they are only held on by the nuts, washers and/or clips on the pots and switches. The component goes through the chassis...then through the faceplate...then you put the mounting hardware on.
Thee thinner metal panels can sometimes use some help from an adhesive (double stick tape) in large areas where there isn't any component. Plexi panels should NEVER have anything used behind the...it can disturb the backfilled paint.
Thanks for the reply!
This came off a Marshall JCM2000. There was definitely a coating of of some type of adhesive applied all over behind it, I had to pry the old one off slowly. Double sided tapes would add more thickness so I'd prefer adhesive if anyone else has any recommendations/experience with this.
Normally I leave them alone but sometimes wierd things happen. A while back on a SFTR the faceplate was loose around the edges. From what I could tell it was from all the smoke the amp had been exposed to breaking down the adhesive.
(amp looked like it'd been in smoke house for most of its life)
I took it off cleaned the old glue off with paint thinner and just used some spray adhesive I had laying around on it.
Use a light adhesive, just to hold it in place, think a little stronger than what Post It notes have.
Regular contact cement will be too much, to boot it has some chemicals added which make it harden along time, in a year it will be almost impossible to pull the faceplate if needed.
Spray type is lighter duty and may work, there's also a whitish water based one , which dries transparent and tacky forever, which turns the faceplate inyo a sort of metallic Scotch tape, if you get what I mean.
The adhesive of double faced tape without the added thickness.