Tips on freeing rusty bolts

[chittychittybangbang]

I added some alternative brands of penetrating oil. I use PB Blaster because it comes in a spray can. I heard about ATF-Acetone so I did some more research and added some more info on penetrating oils to the basic mechanic's tips article:
http://www.myturbodiesel.com/1000q/multi/auto-mechanics-tips.htm . Other tips on freeing stuck bolts inside.

In doing research, I found that almost every internet reference to this test passed on incorrect information. Only 2 sources had the correct information, 1 of which was from the author - so I consider my info correct.

Other brands of penetrating lubricant or a homemade mix - Machinist's workshop magazine did a test of loosening rusty pins with penetrating oil in April 2007. The results are below. Each pin was electrolytically rusted into a hole. If you search the internet, you'll see references to this rusty bolt test, the test was actually done with pins stuck in holes, not bolts. The difference is that a pin has a lot less surface area to penetrate than bolt threads. In addition, the table shows Power steering fluid-Acetone instead of ATF-Acetone because PS fluid was used. Although an ATF mixture works, the author of the test actually used PS fluid (they are similar). Most websites also spread these errors, the table below is correct. The author answered questions about this article and corrected the typo here: homemachinest bulletin board.
Because of these differences, I find that PB Blaster works better than the other brands of penetrating oil and eats rust. I haven't tried ATF-Acetone but I hear it works great and is cheap too. These oils penetrate better if you let them sit and tap them with a hammer. I would also keep Acetone off rubber or plastics. Most, if not all of these are flammable.

Penetrating oil------------Average load (lbs)
None---------------------------516
WD-40--------------------------238
PB Blaster----------------------214
Liquid Wrench-----------------127
Kano Kroil-----------------------106
Power steering fluid-Acetone---53

[pearlgolf]

Don't forget the old torch! It lets the lube seep in farther by expanding the gap.

[chittychittybangbang]

Yes, penetrating lubricants are helped by tapping with a hammer too. I think it loosens the rust and helps it work itself in.

PS, the acetone is probably a thinner to help the oil move.

[wren53]

Good work! Did he test the effectiveness of elbow grease?

[Bilt4ordTUF]

I like Gibbs penetrating oil- Great stuff

[hootyburra]

used to always use wd-40, then found pb-blaster.
That and liquid wrench have worked for me.

well sometimes you need the breaker bar/ torch; or the cut off wheel

[sam007]

I have been using WD40 for so many years and its working the best for me.

[Keithuk]

Well not so much on freeing rust bolts but putting a compound on them so they always come free.

My father used to work in a foundry. The problem they had is if metal is heated and cooled continously the threads become corroded just the same as exhaust threads. They found that applying a mixture of graphite and oil always made the threads easy to remove. Its easy to apply because the oil makes it a paste, the oil does burn off but it leaves the graphite behind.

He had an old VW camper 1968 and he was always fitted exhaust systems due to corrosion. He decided to buy a stainless system so it would last longer, he coated the threads with the compound. Many years later it needed changing again due to the parts that weren't stainless corroding. The nuts holding the exhaust to the cylinder head had corroded with no signs of flats on them. A light grip with moile grips and they came of and the compound could still be seen on the threads. This is a good tip if you keep cars for many many years. I've applied it to my car though the turbo nuts and bolts aren't easy to access.

[JohnP3]

I make up a mixture of Never-size, with ATF and synthetic 90 w gear oil to a thin paste, I have 2 inch brush and a 3/8 wide brush and use is on most everything. It even works on the wheel hubs to the disc's/brake drums and the Aluminum wheel rims to the disc it stops the corrosion and allows for better heat transfer.
If you have to assemble "O" rings that are hard to get together try a little Synthetic gear oil.
I use Move-it penetrating oil, because I got it cheap, seems to do the job, sometimes a little vibration with an air hammer does wonders.

[saak99]

WD40 always help.