Best Penetrating Oil for Stubborn Bolts?

Oils & Fluids
1

I’ve been working on an old car of mine and I’ve hit a bit of a snag with some rusted bolts. I’m looking for some advice on the best penetrating oils to use, especially for situations where bolts are really seized up. I’ve heard a lot about PB Blaster and Kroil, but does anyone have personal experiences or recommendations?

What I’m Dealing With

  • Rusted Exhaust Bolts: These are the worst! I need to get them off to do some repairs.
  • Suspension Components: I suspect these are also going to be tricky.

What I’ve Tried

  • Spraying with WD-40, but it didn’t seem to cut it.
  • I read somewhere about heating the bolts, but I’m worried about damaging surrounding components.

Questions:

  1. Which penetrating oil would you recommend for really stubborn bolts?
  2. Any specific techniques to apply it effectively?
  3. How long should I let it sit before trying to loosen the bolts?

I appreciate any tips or tricks you might have. Thanks in advance for your help!

2

I’ve had great luck with PB Blaster; its low viscosity penetrates rust effectively. The blend of ingredients seems to work wonders on stuck bolts!

3

What about Kroil? I’ve heard it’s really good, especially for precision machinery. Anyone tried it?

4

Kroil is a favorite of mine! It has a mix of kerosene and other agents that get into tight spots. Perfect for stubborn automotive bolts.

5

I’ve used it too! It’s quite effective, but can be a bit pricey compared to others.

6

Don’t forget about Liquid Wrench! It’s formulated for heavy industrial use and has a unique blend that cuts through grime like butter.

6 Likes
7

I had mixed results with that one. It works, but sometimes it takes a while to soak in. Any thoughts?

8

Haha, yeah, patience is key! If you’re looking for something faster, try a brand called Rhino. It’s more of a gel but sticks well!

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9

Interesting! Gel is a different approach. Do you notice any downsides?

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10

In terms of downsides, it can be a bit messier than liquid ops. But for vertical surfaces, it’s a game-changer!

11

That’s good to know! Thanks for sharing. Any recommendations for rusted exhaust bolts?

12

For rusted exhaust bolts, go with a blend that features acetic acid. It helps dissolve rust. You could try ZEP or some homemade mixes!

13

Homemade mixes? Like vinegar? I love a good DIY hack!

14

I’ve had great success with PB Blaster! For stubborn bolts, I let it sit for at least 15-30 minutes. Applying it using a small brush helps target the area more precisely.

15

I’ve heard good things about that! I usually use WD-40, but I might give PB Blaster a try, especially for those tricky bolts.

16

Once you apply the oil, try lightly tapping the bolt with a hammer. This can help the penetrating oil work its magic by creating tiny fractures around the rust.

17

What kind of hammer do you recommend? A smaller one might give me better control.

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18

I usually use a brass hammer to avoid damaging the bolt. It’s less likely to cause marring, plus it’s gentle on the surrounding area.

19

For extra stubborn bolts, I let the penetrating oil sit overnight if possible. It really pays off!

8 Likes
20

That’s a solid tip. Definitely going to try that next time.