Getting rusty bolts out - what penetrant to use?

[JohnG]

The April/May edition of Machinist's Workshop did a test of penetrating oils to see how much force was required to break test parts apart.

Oil Used/ force needed /price per fluid ounce
_________________________________________
nothing 516 lbs
WD-40 238 lbs $0.25
PB Blaster 214 lbs $0.35
Liquid Wrench 127 lbs $0.21
Kano Kroil 106 lbs $0.75
ATF/Acetone mix 53 lbs $0.10 (1:1 mix)

confirmed my fears of WD40 being a featherweight; kind of disappointed in PB Blaster; renewed opinion of Liquid Wrench.

John

PS Sorry for the crummy table. No idea how to insert spaces with this editor...

[Astrowing]

This is good information! Thanks for posting it! Did they indicate how long they let the oil soak? Did they repeat the test to see how repeatable it was with different fasteners?

[JohnG]

I only got a summary of the info; have not tracked down the complete article yet. Lacking that: all the time and patience one can muster up is doubtless better.

I will see if I can get the issue or article.

[simplyconnected]

I agree with Astrowing, this info is fantastic! I also agree with you, John, PB Blaster disappoints me. What's this about ATF and acetone??? I never heard of it and would like to know more about it.

My experience with some rusted bolts is, they become so tight nothing can penetrate when they have become one metal. Exhaust studs are the worst. If by the grace of God they come apart, around where the threads mated, they will look good, but badly eroded everywhere else. Anticipating this, I use brass nuts. With a little heat, they always come off.

This is a good study. I would like to see the article. For decades, I have used AeroKroil (by Kano) and haven't found anything better.

Good thread, John. The biggest part of 'restore' is parts disassembly and cleanup. Advanced rust is the main reason for skinned knuckles and rounded hexes. - Dave

[Guest]

Hey Guys,
Over the years I have found that heat (propane torch) works well to if you can get to the bolt. Take torch and get bolt red hot, they will usually come right loose!
Richard D. Hord

[Guest]

Recently I have discovered that the Kano Kroil works pretty darn good, but my old fave is the oxy/acetyline torch. However about 50 years ago my uncle, who was an owner/operator of a school bus barn, gave me my first lesson in freeing up rusty stuff. He was working on a spit rim rusted together so badly, no amount of pry bars or sledge hammers would break it free. He flipped me a dime and asked me to go buy a Coca Cola out of the bus barn pop machine. Those were the days when a cute little 12oz glass bottle of coke slid out of the top rack machine for 10 cents, maybe it was a nickel. He opened the Coke bottle and poured the coke into the seam of the rim, let it sit 10 mins and with one knock of the sledge, the rim popped apart nice and neat. Nowdays tho with the cost of a can of Coke being $1.00 or more, the price per fluid ounce would be the most expensive, but the force needed may be quite user friendly.

[Guest]

Hey Jed,
I have heard about the Coke before! The formula has changed will it still work?
Richard D. Hord

[simplyconnected]

Torches are great if you can do it without damaging surrounding components. Sometimes, you can't use heat because it ruins the heat-treat, scorches paint, melts plastic, etc.

...The formula has changed will it still work?...

The active ingredient in Coke is PHOSPHORIC ACID. Your dentist uses it to clean out a tooth before setting a crown.

I found two products containing phosphoric acid:
Krudd Kutter (Must for Rust), about $8/qt at some Home Depot stores,
CLR (Calcium-Lime-Rust), although this is somewhat weaker and more expensive.

Certainly, a wire brush works wonders and so does sandblasting. But, we have VERY strong acids that attack iron oxide (rust), and leave the steel alone. Number ONE on my list is Hydrochloric Acid (better known as Muriatic Acid), available everywhere. Wear glasses gloves, and do it outside, with plenty of water available just in case. My plater likes to use sulphuric acid (battery acid), but it doesn't work as well as HCL.

Phosphoric Acid will leave a phosphate coating on metal that will keep rust away for about a year. I usually phosphate after stripping with HCL.

All these acids work twice as fast if you add heat (no, they don't burn). Lye works well with heat, to strip old paint and grease.

I'm still wondering about the Acetone and ATF. - Dave

[scumdog]

Soaked rusty bolts for ages in Coke - it did not remove one iota of rust, maybe made it softer but that was about it.

Soaking in molasses does work for removing rust but I don't know if it can be made to soak into rusted bolts/nut etc to free them.

[Guest]

Number ONE on my list is Hydrochloric Acid (better known as Muriatic Acid), available everywhere. Wear glasses gloves, and do it outside, with plenty of water available just in case. My plater likes to use sulphuric acid (battery acid), but it doesn't work as well as HCL.

I'm still wondering about the Acetone and ATF. - Dave

Yes indeed, HCL or muratic acid is a friend of mine. Never thought about it for removing rusty bolts, tho sounds like a reasonable remedy. 10 years ago HCL was introduced to me as a hull cleaner to remove lake scum and algea from boats. Spray it on and pressure wash off, however a gas mask, rubber gloves and protective clothing are required.

Later I discovered the wonders of this acid for rust removal and removal of much else. I especially like muratic acid to kill creeping charlie, poison ivy and what ever else grows in my yard that I don't want. Muratic kills weeds in about 5 mins. After the kill, simply flush with water to nuetralize the soil and replant with grass seed.

Just this morning I cleaned a bunch of rusty pipe frame I had welded up into a wheeled tripod support for a corn auger. When it is dry I will paint it with POR15 enamel.

I too am very curious about the Acetone/ATF mixture. Oh yes, muratic acid sells for about $2.50 a gallon at Menards. How much more economical can it be?

[JohnG]

some of the motorcycle guys swear by the Muratic acid for dealing with rusty gas tanks.

[Guest]

some of the motorcycle guys swear by the Muratic acid for dealing with rusty gas tanks.

John, yes indeed. I have done 2 motorcyle tanks a '72 chev PU tank. 1st bike tank used the POR15 epoxy kit with their rust prep stuff, PU tank I used sulpheric acid and didn't coat it with POR15 epoxy. Last bike tank used muratic acid and POR15 gas tank epoxy. The 1st bike tank I had done 20 years ago, still have the bike and it is still just perfect inside the tank. Also helps to rattle a chain around in the tank when the acid is inside to scrape off the rust, then do a good rinse with POR15 Marine Clean or TSPhospate and water.

[Woodfin]

I know this is an old thread, but I'm going back through and reading some of the great content users have posted over the years. I just came across a product I'd not used before, I think it's been around for awhile, but I'd never tried it until recently. It works well and now has a spot in my shop. It's called Deep Creep from Sea Foam.

[Jimz Bird]

I recently read of using heat and candle wax or better yet Beeswax. You can get Beeswax from toilet gaskets. You may have a toilet gasket left over if you installed the Red Green "Full Flush Carburetor" that Ray posted the link to.

Man, I musta spent 3 hours looking at Red Green's Youtube stuff. Funny guy.

"If the ladies don't find you handsome, at least they can find you handy"

[simplyconnected]

What's in it?
I recently discovered very good rust removers in 'wheel cleaners'. One of them I found at O'Rilley's and after reading the label I was really surprised it was for sale on the market.

I was looking for an inexpensive phosphoric acid. The guys at the counter had that 'deer in the headlights' stare and pointed towards Gunk. No,.. I wanted something better. I happened to glimpse the wheel cleaners on my way out the door and remembered that brake dust is real hard to deal with.

I picked up a few different brands and started reading the contents. My smile got bigger as I read. These were better and cheaper than the stuff I bought at the 'big box', HD or Lowe's stores. HCL is still the granddaddy for stripping down to bare steel but I hate the 'flash rust' it leaves behind, so I finish with phosphoric.

Some parts are made of steel that is so thin, you can count on breaking it off, like brake bleeders and brake line nuts. I'm in the Rust Belt where we cut bolts off if practical to avoid expensive chemicals and save time. Replacing with new is better and cheaper.