Personally I never really put Loctite back on the screw heads. It sure can't hurt unless you put on way too much. Add in loctite once your 100% happy with the amp and you are done trouble shooting. Looking at this example in the pics it looks like an excessive amount of loctite, so much that it dripped down on one of the transistors. Looks very sloppy... A silicon based heat sink compound is easily found at Radio Shack. I bought a big tube of it on mouser and it will last a long time.