for those hard to reach places or where paint is not wanted, try Fluid Film Spray.
I did a lot of my undercarriage and it looks good and appears to do everything the stuff says it will do.

 

I used eastwoods chassis black semi. I personally wish I would have done a straight satin. I used the pints and added hardener.

 

With the eastwood stuff, that pic looks great and thats the end result I want but not at $59/quart. I would think at $236/gallon I could get a ppg epoxy product.

 

Watch for sales and 20% off coupons. I leverage both right before the holidays and got 2 qts for nearly the price of one along with free shipping.

 

I wish I had used Mastercoat primer and black chassis paint on my truck but at $120 a gallon it's just as expensive or more so than any others. I did use it on my running boards and inside my rear fenders.

 

I have been watching this thread with some interest since I spend much of my time painting things. I have products that I like and some I dislike for various reasons, but to pick nits over cost seems a bit ridiculous. You are going to paint your frame how many times? Does it really matter if you spend $50 or $150 on materials for a one time job? Get the good stuff and pay the money...this is not the time to cut corners. For chrissake, we spend almost that amount every time we fill up the gas tank.