As others have said, WD-40 is a lubricant, not a penetrant. For busting loose frozen fasteners I greatly prefer CRC Knock'er Loose or, even better in many cases, CRC Freeze-Off. In my guesstimation both work better than PB Blaster.

WD-40 is good for things like door hinges and lock cylinders, but for freeing seized fasteners it's not the best choice.

Oh, the picking of a nit in good monkey fashion: It's not how macho you are, but how macho the fastener is, that determines whether a hefty torque removes an intact fastener or a broken one.

 

We always use Rust Check for everything... it's the only thing that keeps the farm running smoothly

 

I have broken bolts before using WD-40 but ever since I been using PB Blaster, haven't broken one yet.

 

Used WD-40, Liquid Wrench plus few others but for me AeroKroil is the sheeet!!! LOL

 

I like WD for removing sticker goo, and it still works good as a flame thrower.

 

Starting fluid is a GOOOD flame thrower!

 

MOUSE MILK. havent heard anybody talk about the mouse milk yet. c'mon guys

 

I was going to give it a try, but it's really hard to find lactating rodents around here.

 

I use PB because it works better than WD-40. I actually use a mix:

70% PB blaster
30% synthetic motor oil

The PB blaster thins the oil A LOT, and when you spray that mix on a siezed or rusty bolt, the oil will go into the threads AND it will not dry if left overnight. It will leave an oily film inside and out.

Basically it is homemade penetrating oil. but i think it works better.

 

50% ATF
50% acetone
Mix in a glass bottle while wearing gloves (acetone is nasty stuff) pour on, tap a little and crank the bolt off.
I've heard this is the best combo but I have yet to try it out because the Knock'er Loose hasn't failed me yet. Some day when I'm bored I'll mix it up and try it out on some of the bolts on that old Thunderbird.