What should I use for securing components on PCB to give mechanical strength

[Yamin]

Hi everyone,
I'm looking for a solution to secure components on a VOX amplifier, I am hoping to get suggestions that would be available from the local hardware stores.
I have had bad experience with 'hot glue' it often gets dislodged.
Some of the components I need to secure does get quite hot, not boiling hot! (couple of 5W resistors).
The research I did on the internet points to natural cure silicon, and also I came across the term RTV, and a local technician suggest 'gasket silicon'. I got myself a bottle and I wanted to see whether it was conductive. I noticed that when applied it has a liquid-ish kind of consistency.
I have included some pictures of the options I could find from the local hardware stores.
Thanks in advance for the help.

[Mr. Scram]

I think Silastic or equivalent competitor is the common solution.

[2N3055]

None of the silicone that smells like vinegar (acetic acid) should be used....
Use some kind of flexible polymer based construction glue.

[fourfathom]

A polyurethane glue (like Gorilla Glue, or 3M 4200) might be appropriate.  These are tough, but have a little flexibility.  3M 5200 is stronger, but not as compliant.  I don't know about temperature range though.

[tboy]

Dow Corning (Dowsil) 3140 or 3145 is best.  3140 is more fluid.