The Best Way to Loosen Rusted Parts
What to Do When a Frozen Bolt Tosses a Wrench in Your Plans
Reading Time: 6 minutes
Is there a best way to loosen rusted parts on the farm? I’m sure there is, but I’m more inclined to say; there’s the best way for each situation. Farmers and homesteaders, out of sheer necessity, work on some old, rusty farm tools and equipment. Sometimes you want to restore an old implement, sometimes the device you want to buy is no longer available new from the factory, and sometimes you need to make due with what you’ve got. In any case, there’s an old mechanic’s trick that can help you.
I’ve been fixing old rusty stuff since I was a kid. Some of my earliest memories are of dad and me working on the old Oliver/White tractor he used to own. It was a definite learning experience and a test of patience, mostly for my father. I had no patience to test, but then again, I was just a kid.
Some days, it would look like there was a rusted bolt or nut at every turn. Every project seemed to take five times as long as it should have, but dad taught me a few tricks along the way.
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Best Way to Loosen Rusted Parts
Patience alone may be the best way to loosen rusted parts since no matter what method you want to use, you need to use some degree of patience with it. Moving too fast, trying too hard, or being impatient either resulted in bloody knuckles, broken bolts or tweaked back muscles. None of which were particularly useful.
Penetrating lubricants such as PB Blaster take time to work, and the more time you let it work, the better. When I started working on stuff myself, I broke plenty of bolts, sockets and, possibly, brain cells. I’ve since learned the fine art of soaking my rusty parts.
Let it Soak
After having a breaker bar knock me in the skull one too many times, I started letting the rusty stuff soak in penetrating lubricant. An hour made a difference, but on the real rusty bolts, I’d spray it down every day for a week. If the part was going to give up under the persistence of penetrating oil, it would after a week. If it didn’t after a week, then I deemed it acceptable to up the stakes.
Leverage is King
Sometimes, even though you’ve soaked a bolt for a week, it just needs a little more convincing. If a socket and ratchet or wrench don’t budge the offending part, adding torque to the equation may be the solution you need.
Breaker bars are a long steel bar with a swivel attachment that fits a socket. These bars are meant to give you a greater mechanical advantage on a bolt or nut so you can “break” it loose. Hence the name “breaker bar.”
Using a cheater bar is dangerous, but effective. I’m not about to say that cheater bars are the absolute best way to loosen rusted parts, but they’ve saved my bacon a few times.
Cheater bars can be any old tubular steel. I keep a few lengths of old pipe of varying length and diameter, which in a pinch, can be used to extend a breaker bar. The longer the bar, or the farther away from the socket you hold that pipe, the more leverage you can exert. Use it sparingly, because impossibly stuck bolts have been known to break loose with the slightest input when using a long cheater bar.
Downside of Cheating
Using a cheater bar can be dangerous, so be sure everyone is good and clear of the offending part. Wear your goggles too, because sometimes things don’t go as planned.
When you over torque a socket, it can shatter or crack when it fails. Doing this to a regular socket is asking for danger, so I suggest keeping a cheap set of impact grade sockets for dangerous duty. I say cheap because you’ll be angry if you break an expensive one.
The other risk you run while using a cheater bar is possibly snapping off the bolt or stud. If the bolt is in a blind hole (threaded into a tapped hole instead of a nut on the other side), cheater bars are a dangerous game. If you’re lucky, the threaded stub left behind after a bolt snaps won’t sit flush with the surface it was bolted.
Welder to the Rescue
If you do have a bit of stud sitting above the surface, screwing a new nut on and welding it to the stub from inside the nut gives you a new chance to win the fight. Even a beginner welder should be able to pull off this simple task. Be sure you give everything time to cool off before trying your luck again.
Drill and Tap
If the welded nut trick won’t work, and the broken bolt is in a blind hole, then you’re stuck. The last resort you have is usually drilling out the bolt and re-tapping the hole. If you’re lucky, you can drill out part of the bolt and use an easy-out device, but I’ve never had much luck with them.
Easy outs are tools that either grip the inside of a drilled bolt or the outside of a broken bolt or stud. They are useful in rare circumstances, but as I said, I’ve not had good luck with them. Their theory is sound, but in practicality, I haven’t seen much success.
The more I work on things, the less inclined I am to fiddle with less convincing methods of frozen bolt removal. For me, using an acetylene torch set is the best way to loosen rusted parts, at least most of the time. If a set of torches are not on your farm tools list yet, I suggest you invest in a good one.
I’ve never met a bolt, nut, or flange that hasn’t eventually yielded to the proper use of an acetylene torch, however, it’s not always a good idea. When working on truck parts that are close to fuel tanks, struts, or shocks, open flame and indiscriminate heat is a bad idea. Bad things can happen, so try another method.
If you want to unbolt a stubborn part with heat, be aware that simply heating everything won’t give you the desired result. The nut or whatever metal has the threaded hole is what needs to heat up, not the threaded shaft of the bolt or stud.
Warming a nut or part that something is bolted into expands the hole in which the object is threaded. By expanding this metal, the hole gets ever so slightly larger. By opening this hole up, tolerances are opened and rusty threads will move.
I’m a fan of impact wrenches, either pneumatic or heavy-duty electric. Many stiff bolts and nuts need a hit from one of these tools to come loose, but they come in handy when heating a nut or bolt. The rhythmic torque pulse has a way of breaking rusty bolts free of their threaded confines easily, especially when heat is applied.
If the rusted offender is just too stubborn, sometimes you need to destroy it to remove it, and then replace it. You could spend hours fighting some bolts, but in the end, if there’s no need to save the bolt or extract the bolt from a part, cutting it may be the most reasonable answer.
There are devices meant to split metal nuts, but I haven’t had great luck with them. Cutting wheels on a grinder, a reciprocating saw, or a good old torch set may be your best bet.
Do you have some other tricks up your sleeve? What do you think is the best way to loosen rusted parts? Let us know in the comments below!