Penetrating oil test
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There have been a couple lately that really contradict the common wisdom. I think the reality is that heat is best unless dealing with aluminum and any penetrant is better than nothing but it takes time for it to work. The longer you can wait the better but that is pretty tough for a guy on flat rate.
kelpaso1
MEMBER EMERITUS
Interestlng that some of the comments mentioned brake fluid as the best rust buster. Would like to see that tested.
jgromada
Well-known member
AvE did a video on this too. Not sure any of these are conclusive.
Burl
Well-known member
I use trans fluid/acetone, seems to work better, less smell.
rustbucket5
Well-known member
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i really like that guy, he got as even as your gonna get for a rust test. i personally have had the best luck with liquid wrench
The only thing I don't like about the test is that its not exactly real world. Who lets their rusted fasteners sit for a day or days? I spray, maybe give it a minute or two, and go at it.
Kroil seems to suffer from an antiquated distribution model. I don't know of any retailer local to me that actually sells it off the shelf so of course the price will be inflated compared to cans sold in the millions to Home-Depot or an Ace.
Kroil seems to suffer from an antiquated distribution model. I don't know of any retailer local to me that actually sells it off the shelf so of course the price will be inflated compared to cans sold in the millions to Home-Depot or an Ace.
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Ole Slewfoot
Well-known member
If I think it will help, I'll advise my customers to spray a troublesome looking part once a day for a few days leading up to a repair. Looking at it as a gamble to maybe save a few bills,they always seem agreeable, and I think it does help.
If im dealing with a crusty fastener i wire brush it, spray it and then tap with a hammer. Leave it to sit for a bit, another spray and tap then try it.
I find either wurth rost off or WD40 specialist penetrant work best. ATF acetone actually works a bit better but the smell makes me feel sick after a few hours of being around it.
If you heat the fastener up then standard 3in1 works well and wicks down the threads quickly.
Brake fluid also works well, i soak parts in it to free them up if possible. ATF mixed with plain WD40 also works well as a soak.
A good but time consuming tip i saw a few years ago is if your replacing ball joints is to heat a bit of high temp moulding wax and pour it into the hex insert in the bottom of the stud, that way if you ever need to remove them it isn't corroded to nothing, and still works to grip the joint from spinning. Never tried it myself, but he had old classics he kept for years so probably changed the ball joints a few times.
I find either wurth rost off or WD40 specialist penetrant work best. ATF acetone actually works a bit better but the smell makes me feel sick after a few hours of being around it.
If you heat the fastener up then standard 3in1 works well and wicks down the threads quickly.
Brake fluid also works well, i soak parts in it to free them up if possible. ATF mixed with plain WD40 also works well as a soak.
A good but time consuming tip i saw a few years ago is if your replacing ball joints is to heat a bit of high temp moulding wax and pour it into the hex insert in the bottom of the stud, that way if you ever need to remove them it isn't corroded to nothing, and still works to grip the joint from spinning. Never tried it myself, but he had old classics he kept for years so probably changed the ball joints a few times.
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seber
Well-known member
ATF and acetone require time to convert the rust to iron carbide and water. For stuck without rust, IE aluminum in iron, heat swollen connections, etc., the whole scenario changes. Heat is the only universal release agent I know of.
BigNuge
Well-known member
Wow....eye opening for sure. I am (at least I was) a big Kroil follower, I have several cans in stock now! I am definitely going to grab a can of Liquid Wrench for my own scientific testing...
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WhiffySpark
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I’ve had great luck with heat and wax.
Personally don’t think there’s much difference between the sprays.
Personally don’t think there’s much difference between the sprays.
zmotorsports
ALLIANCE MEMBER
The results kind of surprised me as I've been using Kroil as an industrial maintenance mechanic for the past 30 years with pretty good overall results. I've also used the PB Blaster but haven't tried the Liquid Wrench, at least not yet, I think I may pick up a can now and try it.
I think he did a good job of being unbiased and keeping the process even across the board.
I think he did a good job of being unbiased and keeping the process even across the board.
sierradmax
Well-known member
Interesting video but I'm not convinced that the oils penetrate between threads. He was able to free the nuts without any oil. I would have liked to have seen continuing torque measurements throughout the nut removal off the stud. I think oil is best suited to prevent heat seizure.
d.mcfarland
Well-known member
No matter what rust penetrant spray I've used, the key seems to be a little shock from a hammer or something to help it.
I haven't had a lot of luck with any of them. The lack of soak/work time may be a factor. I'm not working on my lawnmower. The machinery is not making money while down and I don't have time to let it sit and soak for hours or days. If it gives me too much trouble the grinder is coming out.
DFB
Well-known member
I did like AvE strangely "unscientific" approach to testing 
I used many types over the years and for me Kroil cant be beat and along with ZEP are two of the best I have used. And I never have had much of any decent results with the Liquid Wrench plus the smell just totally *****. Sorry to say I don't buy the liquid wrench. I have had decent success with PB Blaster though many say it doesn't work so go figure.
And wasn't AvE like a WD fanboy?
Any lube is better than none but heat can't be beat
I used many types over the years and for me Kroil cant be beat and along with ZEP are two of the best I have used. And I never have had much of any decent results with the Liquid Wrench plus the smell just totally *****. Sorry to say I don't buy the liquid wrench. I have had decent success with PB Blaster though many say it doesn't work so go figure.
And wasn't AvE like a WD fanboy?
Any lube is better than none but heat can't be beat
Ole Slewfoot
Well-known member
Soak it down while you are ordering parts.:shrug:
anndel
Well-known member
I usually use Liquid Wrench (LW) but have a can of Kroil just to try it. It was on sale at NAPA for $15. I've used 50/50 ATF/Acetone, LW, Kroil, PB Blaster and straight WD-40 and they all work fine....better than nothing.
2ndGearRubber
Well-known member
I've found none are especially useful. I don't have even 30min to let **** sit and soak. I can drill it out after snapping the head off, then fix the threads, faster the 24hour or whatever soak time.
L5wolvesf
Well-known member
I used to use Liquid Wrench a lot (in the old rectangular cans) then it seemed to have changed - I may have also heard something about that here. I eventually went to PB Blaster which works good for me. Whatever I use I try to give it a day to do its thing.
wvhillbillie
Well-known member
My best results have been
1: Kroil
2: PB Blaster
1: Kroil
2: PB Blaster
2mJps
Well-known member
I deal with probaly more rusty stuck bolts than anyone and i have never removed something and found that something has soaked through. If something is tight its sealed. Every time i have something that is stuck i spray it then when it turns i spray it some more but when it finely comes off its dry were it should have soaked in.Then if i soak the bolt the fastener rubes the lube off.
Same here. I do have some Rust Eater I've been wanting to try. I wouldn't take Liquid Wrench for free. I haven't had much luck in the past and can't stand the smell.
paulsomlo
Well-known member
Same here - regardless of which penetrating oil I use, it never seems to get down inside the nut.
You are correct. If you are a millwright (downtime is money) or a flat rate mechanic (beat the book) or even own your own shop and the customer is waiting it is hard to spray something down then wait until the next day. Plus you have all the tools to cut and extract it anyway.
I think these products are more for the guy working at home in his garage without a huge selection of tools.
BigNuge
Well-known member
Lol....professionals use penetrant, every day, all the time. I work on industrial boilers, use penetrant all the time.
I don’t care if I have a customer breathing down my neck, or a salesman crying about his quoted job. I repair the unit my way, and that never includes breaking bolts/studs because they want a rush job.
Do it right, period.
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Someone here needs to repeat that test above and see if it actually wicks through on bolts(both coarse and fine thread) with varying degrees of rust.
Even WD40 does not consider their original product optimum for rust busting. They offer a penetrating oil, that is what should have been compared to these other products. I have not tried it but would like to see how it ranks.
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Bad Habit
Well-known member
Have seen a few videos saying heat and wax works better than anything. Haven't used it yet, but will get the opportunity this weekend changing out some 20+ year old O2 sensors.
BigNuge
Well-known member
One has to wonder wether the wax did that, or simply applying the heat....
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unknownroad
Well-known member
Hobbyists and restorers who have the flexibility to plan their projects out in advance. If you're working on something where you can't just grab a generic piece of hardware out of the bin if a fastener breaks or strips out, sometimes it's worth it to work around the stuck piece until the oil has a chance to do as much as it can.
2ndGearRubber
Well-known member
True, having the ability to spray something multiple times before removal probably improves the outcome. It can't hurt. I often melt the heads off studs to pull the manifold, then deal with extracting the stumps. Lower breakage rate, and the 13mm nuts (now 9mm cones) aren't worth messing with.
No interest in doing it wrong. However, I can't just say "sorry, that bolt looks crusty, let me spray it and come back 24 hours from how". I can't say I've ever had any spray free things up significantly on a stuck fastener. Once it's broken free and is just tight coming out, sure, PB Blaster away.
I never try to break anything (that isn't being replaced anyways). I just can't see sitting around using PB hoping the bolt will come out, even 30min from now (and we know it needs a longer soak than that). Yes, I will use the stuff, but a torch and candle wax usually works better.
Regardless, in the above situation, the fastener still may snap after PB soaking. IME, if it feels like it's gonna snap, and you aren't using a torch to help things along, it's breaking regardless.
My general technique is to spray anything down that looks like it is going to give me trouble with a penetration oil at the start of the project. When I get to a fastener that doesn't want to turn I get it pretty hot with a propane torch, then spray it again to cool it off. I might do that 2 or 3 times. If that doesn't work and I have access I heat it with oxy acetylene until cherry red, then let it cool. If info to cherry red, then cool it has always worked, but sometimes the situation won't allow that...
Joe
Joe
kelpaso1
MEMBER EMERITUS
What I would like to know is what works best when a bolt is seized to the metal sleeve in a suspension bushing. Sometimes it is not possible to cut the bolt head and nut off, especially if the nut is hidden inside the frame.