Dykem use it fitting gun parts

Quite often I see Dykem listed he as being use for fitting. Be careful what product you use. If the container says layout blue it's exactly that and what Dykem has been known for! Prussian Blue is what you should be using and Dykem does make High Spot Blue that is intended for fitting purpose. Permatex makes Prussian Blue as well as others and oil paint coloring will work! In some cases magic marker will work but it should be wiped off after each use!
 For fitting DO NOT use Layout Blue! When writing about it use High Spot or Prussian blue, possibly magic marker. That lets others know you not using layout blue!