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Putting penetrating fluids to the test

We compare four common brands and rate their effectiveness in a Grainews workshop test

It was clear from the beginning of Project CJ3A (which debuted in the February 4 issue) that disassembly of that 61-year-old Jeep was going to be difficult. It had to be fully dismantled at the start of its restoration, but decades of corrosion buildup was battling our efforts to separate nuts from bolts. We knew getting this thing taken apart was going to require a lot of penetrating fluid.

That meant it was the perfect opportunity to compare a few different penetrating fluid brands in the process and see how they rate. We picked four common brands and pitted them against each other — and a lot of rust — in a Grainews’ workshop trial to evaluate their performance.

We tried Loctite’s Freeze and Release, John Deere-branded fluid purchased from a local dealership parts department, 3-in-One Professional and the old standby, WD-40.

However, trying to scientifically measure the effectiveness of penetrating fluids used on a real-world project isn’t easy, because who really knows how much rustier one seized bolt on an old vehicle is than the one beside it.

Despite that, using a full can of each brand during the challenging Jeep teardown left us with a definite opinion on their effectiveness. So, here is how the four different brands stacked up

The results

Starting with the fourth-place fluid, we rated WD-40 last in this group, but that placement deserves a little explanation. As a penetrating fluid, WD-40 seemed to be the least effective. However, its stable lubricating ability was excellent in helping stiff nuts turn off much easier once they were freed from their stuck position.

Penetrating fluids tend to evaporate quickly, but not WD-40. And those stable properties also make it very useful as a long-lasting coating, which is ideal for protecting bare metal surfaces from developing new rust problems during the time they remained disassembled.

So even though we put it in fourth place, it’s something we want to make sure we always have on hand in the workshop.

The 3-in-One Professional did pretty well at penetrating, but our test results rate it third best in this group.

Second best was the John Deere-branded fluid, which was reasonably impressive. It’s a pretty capable product and reasonably priced.

The clear winner in this test, though, was Loctite Freeze and Release. It nearly always freed rusted nuts in just a couple of minutes, much faster than the other brands. Adding a little heat in really tough cases almost guaranteed the nut would break loose. Eventually, we realized if the Freeze and Release and a little heat didn’t work after two quick tries just go straight to the cut-off tool, because the bolt and nut had become virtually inseparable.

Do you have a favourite penetrating fluid or a never-fail trick for freeing rusted parts? Let us know and we’ll pass your tip on to Grainews readers. Email your comments to [email protected].

About the author


Scott Garvey

Scott Garvey is a freelance writer and video producer. He is also the former machinery editor at Grainews.



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