My poor motorcycle is long overdue for some attention and TLC. This will involve loosening some pretty rust-stubborn nuts & bolts. I’ve never known a penetrating oil that did a damn bit of good, but I’m willing to keep an open mind. Maybe that old squirt can of the stuff that dad kept in the basement for decades was just the wrong brand. Tell me what to get – price is no object if it will get the job done.
Oh, and any other tips for dealing with rusty, frozen vehicle parts are welcome too.
PB Blaster. Soaking time helps.
http://www.pbblaster.com/store/moreinfo.cfm?Product_ID=1
Extreme heat (oxy-acetylene torch) is effective. Heat a seized nut to cherry red and it will move for you. This technique has obvious limitations when nearby parts are not heat resistant.
[Disclaimer: The following suggestions may result in broken parts, pissed off people, and much cussing. Proceed at your own risk]
I haven’t found any miracle penetrating oil either, but if you use repeated applications over several hours, even overnight and let it soak that may work.
A couple more tips: A torque wrench or breaker bar gives much more torque than a regular box end, ratchet, etc, as they use the flex of the wrench itself to provide leverage.
Try to tighten the nut just a tad and then try to loosen it. Sometimes just a movement one way or another will break it loose
Heating with a torch may help, but be careful of nearby plastic or other parts that heat may damage.
The standard old cheater pipe method is good if you have adequate room (slip say a 2 ft. piece of pipe over the wrench for added leverage) but be careful not to shear the bolt off.
Try tapping/whacking the end of the bolt with a plastic mallet as you bear down on the wrench. If you use a metal hammer, thread a same size nut over the end of the bolt, leaving it off just enough to whack the nut not the threads. This tapping method works well on stubborn screws also, just tap the end of the screwdriver as you try to loosen it.
If you are using a socket wrench, use a 6 pt socket instead of a 12 pt, as the 12 is much more likely to strip the nut. You might try tapping the wrench with a hammer also, but this can strip the nut also.
Final tip: If you strip, break or otherwise screw up the part, throw the wrench as far as you can (preferably not through the wifes cars windshield as I accidently did once), cuss like a sailor and go have a beer.
Let me just second Gary T about PB Blaster - spent some time working on a farm where everything was basically rusted to hell.
This stuff WORKS. And if it doesn’t work - then you didn’t spray enough or let it sit long enough.
And if it still doesn’t work - then spray it again.
Just my two cents. Next time, we’ll talk about GoJo.
WD-40 all the way 
KROIL is the very best if you can find it. Nothing comes close!
Ditto the Kroil. I buy ‘Curio and Relic’ firearms (old-ass guns), and nothing works like Kroil as a penetrating oil.
Liquid Wrench isn’t a bad product.
Whacking the nut with a plastic or rubber mallet can do the trick. If it’s in an odd area you might want to use a punch.
Heating the nut or bolt can also loosen it.
And of course turning it in both directions can loosen it as well.
If worse comes to worse you can always drill into the nut and use a damaged nut remover. This means you’d have to buy new nuts though…or damaged nut removers if you don’t have any already.
Marc
I’ll second those who recommend Kroil (“The Oil That Creeps”). Good stuff. Let it do its work over night. Every few hours, just tap lightly on the offending bolt or nut with a hammer. That sets up a vibration that helps the oil penetrate. I’ve used it with pretty good results on quite a few rusty old motorcycles.
However, I’ve got to dispute Klaatu’s advice:
Using a torque wrench to loosen tight nuts and bolts will not be good for your torque wrench. It will quite likely throw the calibration off, which will result in inaccurate readings when you’re using it for what it was designed for – tightening fasteners to a specified torque setting.
Several years ago I worked in the shop of a Massey Ferguson dealer. We used a penetrating oil that came in a spray can and came out as a thick foam.The foam held the oil on the rusted part instead of just running down and dripping on the floor. Sorry I can’t give you the name of the stuff since the can just had a part number on it.It was normal for us to go to break and have little balls of foam penetrating oil on every nut on a piece of equipment.
Not exactly a rust busting tip but I often use a nut cracker.
For hopelessly rusted tools n stuff I just soak them in plain household vinegar.
Zyglo penetrant, an oil used to find cracks, will penetrate into the threads. It is made to creep into minute cracks and is the best I’ve ever used. It can be bought in spray cans at industrial supply stores, or from McMaster Carr. It’s pricey, about $10.00 for a 16 OZ can.
PTFE Lubricating/Penetrating Gel is also good and available from McMaster-Carr at about $7.00 a can. After you get it spiffed up, use Tri-Flow PTFE lubricant/corrosion preventitive to maintain it.
Here’s my $0.02: Naval Jelly. Sounds perverted, doesn’t it?
It’s some pink gooey stuff, which I used to de-rust some hinges on my back door. Restored them to their previous luster and re-painted them with Rustoleum. Worked great.
You can find it here or at your local home improvement store (I’d recommend option #2 – this web site looks a bit pricey).
I’ll second (third?) hitting the bolt or screw with a hammer, but I put the screwdriver bit or socket (with bolts that have shouldered heads) on the bolt/screwdriver bit and hit it. This both breaks up the corrosion inside the hole and helps form the fastener to the tool.
WD-40? 
That’s a joke right? Serious rust will eat WD-40 for lunch.
PB blaster is very good, but the best stuff I have ever used is called Maltby Rust Dissolving Penetrant. This stuff will actually dissolve the rust. I cannot say enough good things about Maltby. It has saved my ass more than once. I can’t find website for the company, but I did find this post about removing rusted screws
(I have no financial interest in this company, they just make a great product)
You can also find Maltby at good auto parts stores (not Pep Boys or Autozone)
PB Blaster is available at Most NAPA auto parts stores.
Nuts and bolts? Just torque em off and go to the hardware and get some stainless steel replacements. If its nuts on a stud use a nut cracker. I personally don’t have much patience to try to save rusted hardware when I can find replacements pretty easy.
Agreed. However, many automotive fasteners are not easy to replace, due to specialties of head, shaft, and/or hardness.
Nothing like sledge hammer mechanics.
I have an impact driver, easy-outs, and taps and dies, but you know what? It’s a lot easier to spray them with Zyglo, wait a a day or two, and then undo them, than it is to fuck around beating on them or breaking them off to get them out.
DT, A&P Mechanic
Regarding LMM,s comment about loosening with a torque wrench, I meant the cheap bar type, with the rod and gage thing, not the expensive twist type. Point taken, and I should have been more clear on that.
[QUOTE=Rick]
WD-40? That’s a joke right? Serious rust will eat WD-40 for lunch.
[QUOTE]
Hey didn’t you know…WD-40 can fix ** Anything**
I onne knew a girl with a really tight…nevermind :dubious:
I hate to be the naysayer in this thread (this is my second “taking exception” post), but. . .
I love stainless fastners. I’ve replaced literally more than a hundred fasteners on my motorcycle with stainless pieces. But I don’t like to use them at critical load-bearing points. Torque values are calculated based on the fastener used at the factory, not aftermarket stainless bits. Replacing those bits will require a different torque value, and you’ve got no way of knowing the new value. I’d never use stainless bolts, for example, to hold the brake calipers to the front forks.
Also, when stainless fasteners are used in aluminum holes, an electro-chemical reaction can cause the fastener to seize to the threads, and then you’re right back where this thread started.