Is it possible to remove two parts that have been sonic welded together, without breaking them?

 

If you mean plastic, I have had luck in the past using a sharp razor blade going over the seam very carefully over and over again untill I have a space big enough to get a thin flat blade screwdriver in and try prying the pieces apart. Just need a little patience and a lot of time.

 

Yes plastic, I'm trying to take my reverse lights apart. I think I'll try heat first (oven), then a combination of your idea and a dremel. lol

 

Good luck! What do you have in mind for the reverse lights?

 

I don't know if I can say yet...

 

try it on a salvage part first .If it work on the firts try then it will work on you car .. good luck

 

An oven worked well when I painted the headlight housings on my Cavalier. Take your time and don't heat them too fast.

 

I have a spare set to experiment with.

They were plastic welded I assume? What temperature did you use?