Your opinions on penetrating oils to remove rusted bolts?

Discussion in 'The Coffee Shop ~ Chit Chat' started by PantheraUncia, Nov 27, 2016.

  1. PantheraUncia

    PantheraUncia Epic Member 5+ Years 1000 Posts

    I am sure most of us have used WD-40 and it works to loosen tight/rusted bolts (sometimes or depending on how hard they are stuck). WD-40 is probably one of the cheapest most common penetrating oils out there.

    I have come across situations where WD-40 does not do the job, even hours later some bolts just won't come loose and the last thing you want to do is break a bolt and drill it out.

    I then moved to things like liquid wrench or PB Blaster, Initially it was like wow, why have I been using WD-40 when this stuff was available? It's also a couple more dollars per can. (Moving up the price chart). Generally speaking I haven't had any major issues with products like PB Blaster or liquid wrench.

    Then we move into something I never heard of until yesterday....... something called "Kroil" Koil is $19-$25 for 1 large spray can. The way the mechanic explained it to me is that on really tough bolts like the bolts on your wheel hub that are rusted permanently to the vehicle over 15+ years; Sometimes they will use a penetrating oil and then have to use a blunt air hammer to vibrate the wheel hub to remove it because it will not come off with a breaker bar and elbow grease.

    Kroil really does eat away at the rust and get into the threads and sometimes the bolts will loosen so much that they come out on their own.

    Sounds like magic right?

    So I got on the computer and googled Kroil and its an interesting read....... some people are like it doesn't do anything different than WD-40, PB Blaster, Liquid Wrench; but then you have the counter examples where people in real Industrial fields swear by it as the product to loosen and remove bolts on heavy equipment, use in industrial applications to remove 2.5 inch or longer bolts that are stuck, etc.

    Even the guys on some of the classic car forums are chatting about Kroil on their older vettes and there are people that are like, right what ever and others that are like I will never use anything else since they found it.

    Have any of you heard of this stuff? Is it another "Snake oil? or is this product legit?
    Last edited: Nov 27, 2016
  2. thegawd

    thegawd Rockstar 2 Years 1000 Posts

    iv never heard of Kroil I'll have to take a look into it. now I used wd40 my entire life up until a couple years ago when I ran out and was given a can of liquid wrench, it was a night and day difference. simply amazing. so ya my procedure to losen stuck nuts or bolts is to first spray them and then hit them with a ball peen hammer. if it dosent break right away I grab the tourch and heat up the surrounding area for the length of a smoke or apx 10 mins and then immediately liberally spray with liquid wrench to cool it down and hopefully break the seal. if this dosent work i repeat until it does. I dont use air tools on these cuz I cant feel whats happening and instead use a 4' pipe.
  3. PantheraUncia

    PantheraUncia Epic Member 5+ Years 1000 Posts

  4. Loose Screw

    Loose Screw Active Member 100 Posts

    I've used just about ALL Penetrating sprays over the years. Really they've all worked about the same for me. I get more concerned about what effect the chemicals might have on surrounding plastics and other materials the spray will get on. Penetrating spray and vibration work a lot of the time for me also Heat if you can use it works good too.
  5. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    My next door neighbour works at our local oil refinery. He had a bottle of Kriol (all they use at the refinery) and loaned it to me to loosen a broken sway bar bolt. I had already tried Liquid Wrench without success. The Kriol didn't work either.
    A home made mix of auto trans fluid and acetone is supposed to be a good penitating oil
  6. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    In the Navy we used to use kroil for rusted parts, also as a cutting lubricant when tapping threads or machining parts. I haven't found it for sale in commercial places around here.
  7. PantheraUncia

    PantheraUncia Epic Member 5+ Years 1000 Posts

    Right the mechanic told me I would not be able to find Kroil in any of the local stores, I could only buy it online or direct from them on their website. I can confirm that Amazon and Midway USA carries it in stock. Its cheaper on Midway, but the shipping is more expensive since it is a controlled substance and can only be shipped certain ways. Midway also had faster shipping by almost 7 days compared to Amazon.

    Apparently it is made in Tennessee.

    Would you be able to tell me about some of your experiences with it in the Navy, I mean is it all its hyped up to be over WD-40, Liquid Wrench, PB Blaster since you have first hand experience with the stuff on a regular basis?
  8. PantheraUncia

    PantheraUncia Epic Member 5+ Years 1000 Posts

    Did the home made penetrating oil work with the acetone and ATF?
  9. kennythewelder

    kennythewelder Rockstar 3 Years 1000 Posts

    Kroil is the bomb. I have used it for years. It is used a lot on offshore oil drilling rigs. If Kroil can't get it, the next steep is a torch.
  10. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    I didn't try it on this bolt. It is a very messy concoction, because it's in an open bowl, or can and needs to be brushed on. I have used it on a different truck, different problem and it worked.
    To fix this problem, I had to drill the bolt out.

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