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  • Writer's pictureRoger Maeda

Best Shop Chemicals for the Auto Enthusiast

Every auto enthusiast starts their wrenching career spraying rusty bolts with WD-40. Then they quickly realize that WD-40 is woefully inadequate for breaking stuck fasteners and embark on a quest to find the ultimate rust breaker, spending hundreds of dollars trying out pressurized mystery oil of all sorts in the process.

Everyone does this, yet no one seems to ever share what they discovered at the end of their long and arduous quest. So I figured today I'd share my short list of the most effective shop chemicals I've found in the last 15 or so years of experimentation. Here they are, by category: 

Best All-Round Lubricating Solvent: Sea Foam Deep Creep

Cost: $10 - $15 per 12oz. can

Sea Foam Deep Creep is my favorite general purpose cleaner, solvent, and light lubricant. It helps loosen lightly stuck fasteners while removing nasty dirt and grime from metallic surfaces. It also works well in cleaning carbon deposits off of engine parts.

Deep creep comes out as a very thick white fluid and leaves a very fine layer of lubricant even after it dries. I've found this lubricant does a great job of protecting shiny threaded surfaces, such as coilover threads, from dirt and rust. I also use it to clean off polyurethane suspension bushings since it's one of the few solvents I've tried that won't melt them over time.

The Good

  • Above-average cleaner, solvent and lubricant in a single can

  • Relatively inert - Doesn't react with rubber, polyurethane, or plastics as much as other solvents

  • Sprays upside down and sideways for use in tight spaces

  • Relatively low-fume and inoffensive smell

The Bad

  • What few fumes come out of it are extremely bad for you

  • Flammable. Keep away from open flames

  • There are better penetrating lubricants for seized bolts


Best Penetrating Lubricant: New Holland Iron Gard Penetrating Oil

Made by: New Holland Cost: $6 per 12oz. can

There are very few products out there that breaks seized bolts better than the classic mechanic's homemade special, a 50/50 mix of acetone and automatic transmission fluid delivered through a metal oiling can. Recently though, one of my closest friends dug this up from the parts of the internet inhabited by bored engineers. And after using it extensively for a few months, I now call New Holland Iron Gard my favorite penetrating lubricant.

Obviously, the penetrating power is excellent. Based on some controlled experiments, I'd say it's better than any commercial penetrant I've ever used, and about as good at breaking frozen fasteners as 50/50 acetone/ATF or my old favorite, AeroKroil. Unlike the others, this stuff comes out in a thick, shaving cream like foam and sticks to whatever you spray it on. This means you can spray it from underneath, which is invaluable when working on cars. It also works in the searing heat as well as in sub-zero temperatures, where the others either separate or refuse to spray.

The only downside is that, according to the warning labels, it's incredibly dangerous. The rumor from the forums is that it's a defattening agent, which means that it has the potential to suck all the oil out of your skin and turn you into a living mummy. Use with care.

The Good

  • Sprays in a foam, so you can get into tight spaces and on rusty bolts under the car

  • Highly portable, sprays even in harsh environments and extreme hot or cold temperatures

  • Rust breaking capabilities at least on par with Acetone/ATF

  • Agricultural mechanics have nicknamed this stuff "Panther Piss." Anything with a nickname like that has to be good.

The Bad

  • Incredibly dangerous to your skin. Wear gloves. And long sleeves. Maybe a hazmat suit.


Best Degreaser: SuperClean Foaming Aerosol Cleaner

Made by: SuperClean

Cost: $15 per 17oz. can

SuperClean Foaming Aerosol Cleaner displaced my previous favorite degreaser when the local Advance Auto started stocking it last year. This aerosol cleaner is like a combination of the best qualities of three other very good household degreasers. It has the degreasing strength of Purple Power, an inoffensive odor like Simple Green, and a convenient foaming spray like Scrubbing Bubbles. The fact that I can spray it onto most surfaces without having to worry about diluting it adds to the convenience factor.

The Good

  • Excellent cleaning power in a convenient package

  • Very little scrubbing involved

  • Foam gets into crevices and tight spaces

The Bad

  • Don't let it dry completely or bad things will happen

  • May react with polycarbonate. Don't use it on plastic lenses or they may cloud

Best Metal Protector: Boeshield T-9

Made by: PMS Products Inc Cost: $18 - $20 per 12oz. can

At one point I thought Amsoil MP was the metal protector to have. But after doing a fair bit of testing I discovered that Boeshield T-9 is a much better anti-corrosion spray. Apparently it was developed for Boeing back in the days when their planes weren't made out of composites. Compared to Iron Gard or even Sea Foam Deep Creep, it does not do a very good job of breaking stuck nuts or rusty bolts. However, it is an outstanding anti-corrosion spray and dry lubricant.

Like the Deep Creep, Boeshield T-9 leaves a waxy film on everything you spray. However, the film that the Boeshield leaves is much thicker and stays on much longer. I've used it on the inside of the hitch on my tow vehicle, bolt heads on the underside of the Prelude, and the chain on my road bike. All three of those things have stayed rust-free for months despite being constantly exposed to moisture and road grime. I've also found that it's at least as good as WD-40 for drying things. I use it to clean the piston shafts on my Coats tyre changer and keep moisture out of my air tools.

The Good

  • Superb anti-corrosion properties

  • Safe on plastics, rubber, polyurethane, and glass

  • Very good dry lubricant, can replace lithium grease in some applications

The Bad

  • Not a great penetrating solvent

  • VERY FLAMMABLE. Don't spray it on anything remotely hot

  • Surprisingly difficult to find locally. Try the bike shop if you can't find it

Best Heavy Duty Metal Cleaner: Easy-Off Heavy Duty Oven Cleaner

Made by: Reckitt Benckiser Cost: $5 per 24oz. can

No, this is not a joke. The best heavy duty metal cleaner available comes from the supermarket, not the auto parts store. Whenever I have a terribly greasy part or I need to get horrible road grime off of the underside of a car, I give it a nice thick coating of Easy-Off Oven Cleaner and wrap the area in plastic. Give it a few hours and it will dissolve even the nastiest caked-on tar from any metal surface. It works great on ceramic cooktops too, as I've also found.

The downside is that it's extremely caustic and will also dissolve many things that aren't metal or ceramic. The fumes are also noxious and are probably as harmful to your respiratory system as any of the shop chemicals on this list. Unless you're trying to get the rubberized undercoating off of the bottom of your race car, don't use this oven cleaner on anything that isn't cold and non-porous.

The Good

  • By far the best solvent available for non-porous surfaces

  • Foamy spray makes it easy to get good coverage

  • Makes short work of rubberized undercoating

The Bad

  • Noxious fumes that are so bad I won't use it inside the house

  • Reacts with almost everything; Melts plastics, rubber, and most adhesives

  • Don't let it dry. Leaves white crust that's harder to get off than the grease it dissolves.

  • Goes through nitrile gloves and is terrible for your skin


Best Brake Parts Cleaner: Any Chlorinated Brake Cleaner

Made by: Many reputable chemicals companies Cost: $3 - $5 per 20oz. can

Yes, this one's a cop-out. It's hard to go wrong with almost any chlorinated Brake Cleaner. While known for being super toxic, emitting horrible fumes and eating plastics, the Chlorinated kind works wonders on crusty brake dust as well as black road tar.

Don't mix chlorinated solvents with any other chemicals or use it in any environment in the presence of heat or pressurized gasses. Chlorinated brake cleaner combines with seemingly inert substances when heated and emits extremely toxic gasses. I'm sure you've all heard of this famous story of a welder inadvertently turning chlorinated brake cleaner into Phosgene gas. Use with care.

The Good

  • Removes nasty black tar without scrubbing or even wiping

  • Self-drying. Just spray until you see metal and walk away

The Bad

  • Terrible for the environment. Put a catch pan under whatever you're spraying so it doesn't get into the ground

  • Reacts with common shop gasses and chemicals. Wait until it dries before you apply any other chemicals or weld in the area

  • Turns plastic brittle, degrades rubber

  • Clouds polycarbonate lenses

  • Noxious fumes. Use outside

Best Non-Chlorinated Brake Parts Cleaner: 3M High Power Brake Cleaner

Made by: 3M Corporation Costs: $10 per 14oz. can (significantly cheaper in bulk packs)

Although there's little to compare between any decent Chlorinated Brake cleaner, there are huge differences between brands of the non-chlorinated variety. Many of them simply don't do a good job of cleaning anything. 3M High Power Brake Cleaner is on the short list of non-chlorinated brake parts cleaners that work almost as well as its chlorinated cousin.

The "High Power" on the label refers to the force with which the solvent comes out of the can. This stuff sprays like it's been pressurized by a power washer. This means you can be further away from your target and still get the crud out of those tight cracks and crevices. I use this stuff to clean oil and road tar off of the Prelude's engine and transmission before each race weekend. Keeping the engine bay sparking clean helps find those odd oil leaks that inevitably spring when racing a production car. I buy it in boxes of 24 because I use so much of it.

The Good

  • Powerful spray helps clean spots that you can't reach

  • Works just as well as chlorinated brake parts cleaner

  • Dries reasonably quickly for a non-chlorinated solvent

  • Better for the environment than the chlorinated kind

The Bad

  • Still not good for plastics or rubber

  • Fumes are still pretty bad. Ventilate well or use outside.

  • Expensive. Buy in bulk where possible


Words of Advice


So there's my short list of essential shop chemicals. Hopefully this will save you a bit of time and money when you're working on your 10 year old car for the first time or when you can't get your well-worn lawnmower apart for service.

One last piece of advice before we wrap up. While you're waiting to check out at your local auto parts store or on your favorite internet shopping site, throw one of these into your shopping cart:

Every one of the shop chemicals listed above is bad for your skin, nose, eyes, lungs, and pretty much every other part of you. Work in a well ventilated area, stay away from the fumes that this stuff emits, and always wear gloves when using shop chemicals. You'll live a lot longer when you do. 



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