Clean the bike first, always keep that thing pretty clean it will run better and be less likely to have issues like that. They can still happen clean or not but less likely to happen when things are clean and well maintained.
Make sure you use the same spot on the rim at every point you are checking and bending the hanger. I recommend the valve stem that way you have the same reference point and it is an easy one to find and use. The heat will help as well but can damage paint a little but honestly black nail polish/touch up paint should solve that pretty well.
FBinNY Do you do a beer batter for your dropouts or maybe a thinner tempura batter or is it a three step dredge? One good frying tip is use alcohol like Vodka instead of water as it will make things crispier.
