How can I remove old LEGO bricks that are stuck together?

Question

Brought my childhood LEGO sets from 1970's and 80's for my kids. The pieces attach much tighter together than sets purchased recently.

Can something be done to loosen the attachment without damaging the bricks?

Answer 1

Try using this brick separator tool

Source: https://shop.lego.com/en-US/Brick-Separator-630

A simpler version used to come with older sets. Some of the images demonstrate how the tool may be used with different kinds of pieces.

Source: http://www.philohome.com/remover/remover1.htm

Two brick separators may be used for maximum separating efficiency for certain types of stuck brick situations.

For example, when two plates are stuck together:

Alternatively, using it as a lever to remove tiles

Source: http://thebrickblogger.com/2010/11/lego-brick-separator/

Answer 2

(@emagar has done the editing asked by moderator)

Leverage does the trick with no need for spacial separators or tools that might damage LEGO plastic. Use a long brick as lever, a smaller brick as wedge. Attach the wedge slightly towards the center of the lever. Plug the stuck brick to the space left free, in contact with the wedge. Apply diagonal force to release the stuck brick. Quite amazing.

 _________________________
 |________________________|  lever
     |__|  wedge


           ___
   ________|__| stuck brick (seen sideways)
   |          |
   |          |
   |__________|


     _________________________
     |________________________|
  ____|__|__|<-here  force |
 |          |              V  
 |          |            here
 |__________|

See https://youtu.be/KbJV90f6GpM

Try using this technique, fast and easy!