Goop... bonding componants together in older effects??

[armdnrdy]

While reviewing gut shots of older effects, I've come across something in several instances that I am unsure of. (Well to be honest....there are many things I'm not sure of!)

There seems to be some sort of "waxy looking" bonding epoxy applied to components that keeps them physically tied together. It is not uncommon to see a capacitor tied to a resistor or a couple of capacitors tied together.

Here's an example pic:
http://www.aronnelson.com/gallery/main.php/v/diyuser/Cap+and+Res.jpg.html

I'm wondering if it is to lessen the effect of electromagnetic fields surrounding the capacitor. If that is true, how do we know when to apply this technique and why do I not see it implemented in newer designs?

[Seljer]

The goal is not to dampen fields but simple mechanical stability. Vibration is excellent at destroying soldered joints.

And if you ever go read through any physics 101 type book, you can learn that outside of a capacitor, the charges on opposite electrodes cancel each others fields out, (apart from edge anomalies).

[armdnrdy]

I understand and have seen components attached for mechanical stability but I have also seen service manuals giving explicit instructions to connect two components together of average size and weight while leaving similar or larger components flying in the wind.

I have also seen this in board designs. The board in the picture I attached has 32 capacitors of varying sizes while only the one in the image is attached.

[wavley]

I don't know about this instance, but it's pretty common practice to do this to thermally couple components, like the transistors in the VCA'S of DBX compressors.