Rick's Free Auto Repair Advice

The Best Rust penetrant for rusted bolts — My choice of the brands

I choose PB Blaster as my choice for the best rust penetrant

I’ve used just about every brand of rust penetrant and my favorite is still PB Blaster. You wouldn’t know that by reading the questions people ask when trying to remove rusted parts. It seems all those people use WD-40 because it says “loosens rusted parts” on the label. I agree that it’s a great all-purpose lubricant. But if it’s a rust penetrant, then why do they sell a special product called Specialist Penetrant Spray?

These are all excellent rust penetrant products

PB Blaster, Knock’r Loose, FreezeOff and Liquid Wrench are very good rust penetrant products. Any of them is better than ordinary a general-purpose lube at loosening rusted and stuck fasteners.

best rust penetrants

Each has its advantages and disadvantages including the possibility of staining car paint.

How to use a rust penetrant product

Most people think that spraying on a penetrant is all it takes to remove a rusted bolt. Not true.

Start by cleaning the area around the rusted bolt with a wire brush. This will allow the penetrant to soak into the threads better. Make sure to remove any dirt or grease that would prevent the solution from wicking under the bolt head or reaching the threads.

Apply a generous amount of rust penetrant spray onto the rusted area and let it soak in for 10-15 minutes. The penetrant will creep into the threaded areas and small cracks caused by the rust.

After letting it soak, take a hand impact driver and impact screwdriver and try loosening the bolt. The impact driver accomplishes two things; it creates vibration that breaks up the rust and it provides extra turning power to the bolt head.

If the bolt still won’t budge, apply more penetrant and let it soak longer – up to an hour. The longer the penetrant sits, the more it will work into the threads. You can also try lightly tapping or vibrating the bolt while the penetrant soaks to help it penetrate deeper.

A hint about rust and vibration

If you think of rust as if it’s a glue and sealant, then you can more easily understand why it’s best to break the rust for the penetrant to wick into the threads and lubricate them.

That’s why I always try to shock the bolt using a hammer or my air chisel fitted with a hammer bit. It shatters the rust and drives it farther into the threads. Others use heat to make the bolt expand and contract. The FreezeOff works by chilling the fastener to break the rust.

If you’ve tried ordinary WD-40 general-purpose lubricant and it isn’t working, try my choice for the best rust penetrant, PB Blaster.

© 2012 Rick Muscoplat

Posted on by Rick Muscoplat



Custom Wordpress Website created by Wizzy Wig Web Design, Minneapolis MN