CRCKnock’er Loose Penetrating Solvent 03020 – [Reddish] 13 WT. Oz., Industrial Grade Penetrating Solvent and Lubricant

I've used Kroil for many years after my father, who was an aviation mechanic, introduced it to me. It's the best penetrating oil I've used but it's very expensive. In the past, it was hard to get because you had to order it directly from the manufacturer but since they were bought out by another company, it's much easier to order it as a consumer.I was pleasantly surprised to find out that since Kroil's utility patent ran out, CRC came out with Knock er Loose which has the same formulation as Kroil. I have not seen it available locally so it's not as cheap as the ones you can buy in the store but it's still 1/2 cost of Kroil. Recently I used this a couple of rusted screws that secures a burner on a gas stove. The first one I didn't use any penetrating oil and snapped the head off because I thought the screw was turning. The other one I doused it with Knock er Loose, waited a couple of minutes and then turned the screw back and forth until I got it to break free and move slightly. Once it starts moving, then you know your almost home free. Keep spraying it with penetrating oil every now and then and turn it back and forth until you feel resistance. Patience is key - don't think you can just unscrew it forcibly because it's loose. The resistance you feel is the rust caught in-between the threads so you need time to break that loose with the penetrating oil. Working the screw back and forth not only helps break up the rust but also helps the penetrating oil seep further down into the threads.

This product is amazing. It is a cost-effective way to get out stubborn bolts. No matter how rusted they are I can count on Knock 'er loose to get them out!

Wow this stuff works miracles. Unstick even rusty bolts. Like charm. Unstuck pull chain on pulley also. Well worth the money . Saves from having struggle get bolts loose and nuts off. Unsticks lot rusty thing.

Great stuff, works really well.

I refurb antiques, & a LOT of them have stuck screws, so I've always used WD-40 to get them out. Since many are still not loosened with that, even after multiple applications, I've been trying different brands recently.This CRC brand certainly smelled the best of the 3 brands I've tried. Since I work in a basement workshop, there's no good ventilation, & whatever I use, I'm stuck smelling it.Obviously, I don't sit around inhaling it any longer than I have to, but it does take a few minutes to spray all the parts, & then get out, so it can sit. I can only hold my breath so long, then I'm going to get the aroma, whether I'm done or not. (Geeze that Liquid Wrench is the WORST! I had to throw it out! Even in the Garage - It stunk us out!) WD smells like oil, LW stunk to high heaven, & this CRC smells kinda sweet - like candy. Not sure that's a good thing, but if you gotta inhale stinky stuff, may as well not make it horrid smelling. (Though there's a case to be made that if it stinks, you'll hurry up, & if not, you may dawdle. Hurry up, either way, & don't breathe the fumes any longer than you have to.) I always do my spraying on the way out at the end of the day, so it can sit overnight before I have to go back in.As to loosening the parts, I've tried it on 3 stuck screws that WD didn't loosen. It loosened 1, but not the other 2. Hard to say if it's better than WD, but it's probably no worse, & the smell is better. If smell outweighs the cost to you, go with the CRC. If cost matters more, I'd stick with the WD. Neither are magic, & both are better than breaking the screws.

Good for bolts and nuts

Smells so much less toxic than other brands. Worked good for my use.

Really Works as advertised. Very impressed.