Kroil

[Clark]

It must be more than 10 years ago I captured this off the internet, when Walt Berger owned Berger Bullets. That is what started me using Kroil.

Q: If I use Moly Coated bullets how should I clean my barrel?
A:
The following is one way to clean when using Moly Coated bullets. It is
not likely the only way you can clean if you are using Moly Coated bullets.
1. Push one patch wet with Kroil Oil through the barrel
2. Repeat step 1.
3. Push one dry patch through the barrel.
4. Repeat step 3.
5. Push one patch wet with Butch's Bore Shine through the barrel.
6. Repeat step 5.
7. Let the barrel soak for 5 to 10 minutes.
8. Push one dry patch through the barrel.
9. Repeat step 8.
10. Using short strokes back and forth push one patch wet with USP or JB
Bore Paste through the barrel.
11. Push one patch wet with Kroil through the barrel.
12. Repeat step 11 twice.
13. Push one dry patch through the barrel.
14. Repeat step 13 three times.
15. Use bore scope or visually inspect muzzle for copper fouling.
16. If copper is present repeat steps 10 through 15.
17. If you are storing the rifle push one patch wet with quality gun oil
through the barrel.

 

[kusan]

Kroil vs homebrew rust breaker

This test appeared in "Machinists Workshop" a while back. The magazine reported that they tested these products for "break out torque" on rusty bolts.

Average torque load to loosen rusted nut:
No oil: 516 ft.pnds.
WD-40: 238 " "
PB Blaster: 214 " "
Liquid Wrench: 127 " "
Kroil: 106 " "
ATF/Acetone mix: 53 " "

ATF/Acetone mix is 50/50 automatic transmission fluid+acetone.

 

[45_auto]

This test appeared in "Machinists Workshop" a while back. The magazine reported that they tested these products for "break out torque" on rusty bolts.

Average torque load to loosen rusted nut:
No oil: 516 ft.pnds.
WD-40: 238 " "
PB Blaster: 214 " "
Liquid Wrench: 127 " "
Kroil: 106 " "
ATF/Acetone mix: 53 " "

ATF/Acetone mix is 50/50 automatic transmission fluid+acetone.

How in the world do you know that the rusty nuts used in the tests were all equally corroded to have the same initial breakaway force?

The rusty bolt that broke free at 53 ft-lb with acetone could have broken away at 54 ft-lb with no oil, or 40 ft-lb with any of the others.

I've seen rusty nuts on a part that had to be torched off, and rusty nuts that looked identical on the same part that come off with finger pressure.

Might be interesting if someone actually did a scientific test.

 

[Unclenick]

45_auto,

It may have been scientific if that word "average" applied not only to the nuts but to the tests. That is, if they had, say, 60 similarly rusted bolts, selected 10 randomly for each test and got standard deviations that were small enough for each, the test would be reasonably scientific. It would be nice to have more detail to tell.

Acetone and ATF are in Ed's Red, which bears a resemblance to John's formula.


Mill Rat,

Your measurement does not appear to be valid. If you look up the pH of oils on the web, the most common thing you will see is the statement that you cannot measure the pH of oils because they don't have one. pH is a measure of the hydrogen potential of aqueous (water-base) solutions. Since oil has no water, it can't have an aqueous hydrogen potential, and that is the basis for those statements.

That said, some non-aqueous solvents actually do have some degree of hydrogen potential and it can be measured and made into a pH. However, the resulting scales are completely different from the aqueous pH scale. Also, if you have detergents or surfactants or emulsifiers involved, moisture can be suspended in oil and dissolve sulphate ions or other acidifiers. These are the acids they worry about in car engine motor oils. But again, those are actually dissolved in water. They only happen after the oil is being used and exposed to water vapor in the gasoline/air combustion products. They are not in the oil when it is new.

The bottom line is, where oil rates on a pH test paper designed for water-based solutions does not accurately reflect any hydrogen potential the oil may have. It certainly doesn't tell you that the oil is going to etch steel. Acids eat bluing off faster than they etch steel, and if Kroil did that, we all would have heard about it by now.


Using Kroil: Like most penetrants and solvents, this stuff needs adequate time to work. I let it sit a day on rusted parts. I do the same with Gunzilla or other penetrants. In a bore, anything less than a 5 minutes sit is usually wasting the potential of the solvent. That applies to most bore cleaners. They can keep working up to 20 minutes, according to a 2006 article in Precision Shooting, but I have personally witnessed Gunzilla continuing to work to soften carbon for weeks.

Some folks also swear by some natural oils like wintergreen oil for penetration.

Board member Hummer90 says the least expensive effective carbon remover is Mobil 1 motor oil. Modern detergent motor oils are 15-30% additives. Mobil 1 has some very effective ones that can clean the carbon from an engine. Hummer90 reported it working at least as well or better at carbon removal than any of several carbon removing bore cleaning products, and says it is what the AMU has adopted for all their firearms maintenance. I got the 0W20 grade to have the thinnest form. It does work very well. Coat a bore with it using a loose fitting patch and let it sit long enough and you may be surprised what all comes out. Again, five minutes is minimum, but it works best if you put it in the barrel when it is still warm. It is designed to work in a warm engine, after all.

In all my experiments I let some of whatever bore cleaner I am playing with at the time run down the bore from the breech end while I'm still at the range, plug both ends of the barrel for transport, and don't patch anything out before I get home (50-60 minutes, depending on traffic). With something benign, like Mobil 1 or Gunzilla, I often let it sit until the next day. I want the stuff to make everything go away while I'm driving or sleeping, and pretty much you can make that happen. Mostly I use Boretech Eliminator for this nowadays, as it attacks copper, too, but it's a good procedure with everything.

Give your cleaning agents time to work.