Taking stupid white glue off pc boards

[tkamiya]

I'm restoring a power supply board for HP53181A.  There are those annoying white glue or something everywhere, mostly near electrolytic caps.  Is there a good way to remove these?  I've been using needle nose and tweezers, but there's always a chance of destroying nearby components.  It didn't react at all for IPA. 

[bob91343]

That is likely silicon rubber, a pliable insulating compound.  I use your method.  It is there for protection from shock, such as dropping a unit.  Only heavy components, usually.  I don't know of anything that dissolves it without destroying everything around it.

[Bud]

I first make a few cuts through that stuff, close to components, using a sharp knife, then remove piece by piece.

[tkamiya]

I was afraid of that....  I'm almost tempted to custom make this power supply...  It's always on and it's so fragile especially when fan fails.  I see clear sign of gross overheating on PCB material.  In fact all 4 I have have some type of heat related degradation.