Rust Penetrant

[ModelTWoods]

I know this topic has been discussed many times on the Forum, including how to make "homemade" penetrating oil, but this is a comparison question between two commercial brands. For those of you who have used these brands : Kroil and PB Blaster, which do you find more effective? I can buy a FIVE gallon pail of PB Blaster for roughly the same price as only ONE gallon of Kroil, both on Amazon.

[Jones in Aiken SC]

I vote for Kroil. Best I have ever used.

[Mike Silbert]

This is my personal preference and opinion:

I use PB Blaster, it works well and is easy to get.
The local hardware stores have it.
And it has no silicone so it is paint safe.
While I know there are products that are (maybe) slightly better they are hard for me to locate.
I could make my own (ATF / Kero mixes) and get marginally better performance but I am not interested in stopping working to make up a solution.
In really troubling cases I have made my own in the past, but that is rare.
I also have WD40 on hand but it only gets used when smell is offensive (household stuff) or I can not find a Blaster can.
She finds the Blaster smell offensive so it stays in the garage.
WD40 is not as good at breaking rust issues but it can work.
Given a choice heat works best of all.

For me it is a balance of functionality, practicality, cost, and convenience driving my decision.
With my tight budget and lots of things eating into it, cost is a large factor for me.
You will have to decide what the best bang for the buck is for you.
Others will have different opinions.
Mike

[Daisy Mae]

I would vote for Kroil being best, having used it in a shop, but price/availability steers me to using PBB for personal use.

My question back to you is how much do you use to justify a 5 gal bucket, and/or, how long would you expect it to last? Issue being the loss of volitiles over time degrading the solvent.

[Humblej]

I agree, Kroil.
However, for many 100 year old fasteners I dont bother with penetrant and go right to the blue wrench too.

[mgarrett]

Availability for Kroil was an issue, but I was surprised to find that O'Reilly Auto Parts now carries it in the store. At lease they do here in Corsicana, Texas. Yes, it's pricey but still the best. One of my big beefs about rust penetrant is that many of the spray heads on the cans are difficult to control the output and deliver WAY too much when depressing the trigger - a lot of it ends up on the workbench or the shop floor. A big waste of product and money. The Kroil I've used in the past and now have allows one to dispense a small amount or large depending on how hard you lean on the button. As pricey as it is, that's one big plus...it seems to last longer.

[DanTreace]

Aero Kroil gets my vote too. Use a wire brush first to remove heavy debris that restricts the penetration. Aerosol applications for underneath use too!

The narrow spray tube concentrates stream to the fasteners joint. Better than PB Blaster IMO.

[modeltspaz]

I worked for Boeing, Downey and Huntington Beach for 6 1/2 years. I worked in the Structural Test Lab at Downey, and at Huntington Beach. We tested Delta II and Delta VI Heavy rocket stacks. Of course these tests were non-fired and were performed outside.
The facility was located about 2 miles from the beach. The salt air was brutal there. The Kroil product we used was Sili Kroil. This stuff just melted the rust off the hardware that was left out in the weather for years. We bought it by the case.
If we had a stuck piece of hardware, we'd hit it with a liberal dose of Sili-Kroil, then the oxycetelene wrench, then more Sili Kroil and walk away for a bit. When it was cool enough to handle, it would almost unscrew itself.
The downside is, it's pricey. Anyway, give it a try.

Mike Spaziano.

[Loftfield]

I do not understand the urgency to buy spray can stuff, or other prepared solutions at higher price. For penetrating oil I make my own from acetone and auto transmission fluid, cheap, super effective, and I make up a quart at a time so no time wasted making as needed. It keeps in a closed old acetone steel can without losing volatiles. For overall rust cleaning I use vinegar diluted 1:4 with water. Cheap, effective as vinegar does not attack clean metal, easy, easy, easy, cheap, cheap, cheap. No spray can so material does not fly off into air or onto bench and floor. Similarly, I make my own degreaser from several ingredients that replaces the no longer available Gunk Super Concentrate. Formula available online.

[ModelTWoods]

Thanks to all for input and suggestions. My situation involves submerging a Kingston regenerator intake and exhaust manifold, made together, which makes submerging it in penetrant harder than soaking a smaller part like a carburetor in a sonic cleaner or centrifuge. I have considered putting the manifold in a 5 gallon bucket and placing as many bricks in the bottom of the bucket so as to displace the penetrant, forcing the level of penetrant to go to a higher level in the bucket so 1 gallon of penetrating oil would go further for soaking needs, as an alternative to buying 5 gallons of penetrant. A forum member suggested placing the part in a heavy duty plastic bag so that the penetrant could be confined to a smaller space around the part, allowing a smaller amount of penetrant to be used in the soaking process. My concern is if the chemical might 'eat' through the plastic bag. I guess if I tried this method (instead of putting bricks in the 5 gallon pail) that I could put the plastic bagged part in the pail in case the bag were to leak.

One more question: regardless of the solution used, commercial or homemade penetrating oil, how and where do you dispose of it properly? Back in the 1950's and 60's, before environmental concerns were addressed, many people including myself, used to just dump used motor oil and chemicals into the soil when disposing of it. I wouldn't dare do that, now.

[Ruxstel24]

For the most part I use GM rust penetrant…used to use the same stuff years ago from AMC at the Jeep dealers I worked at. It was called heat valve lubricant then, for the old exhaust manifold heat valves. It works pretty well but sometimes the flaming nut buster is the only way. It’s not cheap but less than Kroil.
Another thing I have started using is Fluid Film rust inhibitor. I use it in a rustproofing gun a spray cars around here the help fight the salt. But it works pretty good on rusty bolts too. Has a wicking effect also. It seems to work good on rusty bolts that are in aluminum better than some things. Available at NAPA and Amazon. They make a spray can too.

[speedytinc]

I don't see the point of submerging the unit. Penetrating oil will "penetrate" into any crack, thread & connection point.
I would spray all the places that need it, maybe twice a day for several days. Consider using the "Blue wrench" first around all the stuck joints.
Or are you thinking this fluid will remove all the rust? That's a different type of product.

Back in the day, one could/would dump such chemicals into the storm drains to kill the dolphins.
Today, in my area, we have hazardous waste centers that will take the stuff, like used motor oil also, for no cost.
Another option, especially well suited for the home made mixture, is to put in a 5 gal can with the lid off & let it evaporate.
This works great with bad gasoline.

I don't see an answer to your question.
"but this is a comparison question between two commercial brands."
I am also interested in the answer.

Does the PB work as well or nearly as well as the Aero-kroil??

The last Aero-kroil I bought, in the "economy" sized can was $40. Ouch. I see that its over $30 for a 16oz can.
I see that PB is $7 @ Horrible Freight. Or, maybe, I make my own.
If they are comparable, I would get some PB.
I use the Aero-kroil now. It works very well.

[Dan Hatch]

Induction heater for bolt removal.

[Mike Silbert]

Here is a link to the often quoted and referenced test of penetrating fluids.
https://www.mtfca.com/discus/messages/4 ... 1404246100

As I said before I usually use PB blaster most of the time.
To be more specific it gets used most often when I put something away for later disassembly giving it time to soak.
ALL fluids work better the longer you let them sit unless they evaporate first.
When I get back to it later it usually cooperates.

I also use it to stop the squeak when turning fasteners or to drop the rotating resistance.
It is a quick try on fasteners that works some times and sometimes not.
When they are really stuck I find that penetrating fluids do not do a whole lot unless you are really patient.
My shop time is usually short so waiting for it to work is often not an option for me.

If you are serious about breaking something loose the top winner is heat.
It releases Loctite, rust, and cleans up old grease, rust, and other goop.
It even activates old grease turning it into a bit of a lubricant as it boils away.
The inductive heater and blue wrench are the seriously stuck fastener problem solvers.
Even welding on the head of a bolt will break it free. With or without drilling a small hole down the middle.

I use a multi level approach to removing fasteners that steps up to match the needs and desires of the task and time.
Penetrating fluid is only one part of it.
Mike

[OilyBill]

I read an article about the chemical makeup of Kroil. It used to be made by a small company in Tennessee. The owner held a patent for using a super-refined oil, which is what gives Kroil it's penetrating power. It really DOES sneak into a space as small as one millionth of an inch. They used to send me flyers all the time, and I bought numerous spray cans, and also 1 gallon cans of Kroil and Aero-Kroil, especially when they would send me their discount coupons, which arrived monthly.

A couple years ago, the family sold it out to some venture capitalists, who reorganized the company, and decided to raise the prices. The prices went up about 4 times, versus what they had previously been. I still order it, but now in just 8 oz cans, and I will probably never buy a gallon can again. I think my last gallon can, which I am at the bottom of now, cost me about $19.00, which included the shipping. I believe a full gallon of Kroil now is well over $100, and the shipping is additional.

Kroil IS very good stuff. It is the BEST penetrant I have ever used. It has NEVER failed to make even the most rusty assembly disassemble with just hand tools, with NO RESORT TO TORCHES, chisels, or other crude methods. I have not broken a bolt, or sheared a screw off, in MANY YEARS. Between Kroil, and then EVAPORUST, the parts I work with look as if they are new from the factory. No erosion, no sandblasting damage, all the rust completely erased, and the fasteners and parts look like they could have been mailed from the original auto factory as spare parts. The metal is smooth, and unmarred. (Except for obvious wear areas, which must then be repaired with bronze or steel insert rings in areas that show heavy wear, to return them to completely like-new condition.)

I know that people have said to just use some solvent with automatic transmission fluid in it, and it is "as good as Kroil" but my opinion is that it is NOT. The company that holds the rights to the Kroil formulas, possess the magic that comes from using the super-refined oils that the owners of Kroil developed and patented years ago.

Like Evaporust, Kroil is a special chemical that DOES possess special qualities, and these are unique to that special product. The problem I see with Kroil is the EXTREMELY high price per ounce of the material. I used to literally wash down an engine with it, and then let it sit before I tried to take it apart. NOW, I apply it with a delicate squirt can or syringe, directed only onto the specific part I am trying to disassemble, and repeat the application dabs over a longer time, to achieve the same results, but at a more reasonable price. It takes longer to disassemble mechanisms, but it still is the difference between success and frustration, damage and simple disassembly into component parts. After 50 years of using it, I am very sure that anyone who has used Kroil for an extended time will agree with me.

I just want people to understand that it is NOT just salesmanship, or advertising, that makes Kroil a good product. It is intrinsically good, just from it's very makeup. That is what makes it special. As with EVAPORUST, there IS a specific difference you will see when you use it.

I have no interest in the Kroil business, or any connection with them, beyond being a long-term purchaser and user of their products, which I have always paid the prevailing price for. I can only say that Kroil lives up to every claim they ever made for it.