Whats the white glue for electronic parts call?

[ptt81]

I've waited almost 1 1/2 weeks to get to post in here...but im glad i did, glad to be here. I did the mod base off someone from this forum I forgot who it was. Yes it is the white stuff, semi-flexible as Brian said, such as inside a PC power supply, xbox power supply, so on and so on but I don't know what it is or where to get them. I got some shoe-goo, but im worry that it won't take the heat and fall apart, the caps goes to around 135-140F. I install some bigger caps on my MM replacing the 3 original ones and i made it stick out to the side but im afraid they will break off on a hard run or something, i need to hold them down as hard as i possibly can. Any other suggestions?