Some thermal pastes are good for air cooling, others for liquid cooling, some are generally efficient, others are not. But as our colleague Igor Wallosek discovered, there is a thermal paste that stinks and damages coolers. That thermal paste — Amech (Aimac) SGT-4 made in South Korea — appears to be quite popular in online stores around the world because it is cheap and gets favorable user reviews. Yet, SGT-4 appears to be a chemically reactive blend that stinks due to acidic vapors, permanently damages CPUs and coolers with pitting from corrosion, and causes coolers to glue to the chip. The TIM also doesn't meet its thermal ratings due to the pitting.
SGT-4 (not among the best thermal greases that Tom's Hardware has tested) is based on PMDS; however, chemical testing and user evidence indicate that it is not a standard silicone-based thermal paste, as it adds a reactive acetoxy-curing RTV silicone, a substance that seems to release acetic acid when it contacts moisture, based on Igor's findings. This additive — likely methyltriacetoxysilane, according to Igor's Lab — was apparently used to make the grease cohesive and adhesive when applied at thin bond lines, but its reaction produces acidic vapors that cause metal oxidation and the smell of vinegar.
