For me, Kroil has always been the gold standard when it comes to a penetrating oil for loosening stuck screws. I've never had a screw that wouldn't loosen up after an hour or so of an application of Kroil, most after only 10-15 minutes, but I have now met the screw that Kroil can't handle. I have applied a ton of Kroil around this screw and it has sat for more than 24 hours and won't budge a bit. It isn't rusted, just a buildup of years of dried oil, grease, etc, so I'm shocked it isn't moving, which gets me back to me original question...........

Is anything better than Kroil and if so, what is it?

Thanks much!

I don't know exactly what you are trying to loosen and Kroil is the best in my book too but you may try heating the nut or bolt with a small propane tank or mapp gas then when it's hot quench it with alot of Kroil and it should come loose. If you are trying to get a screw out of a gun or anything similar disregard above. If you are trying to get a nut off a bolt heat the nut not the bolt and the heat will expand the nut and quenching it will add some lube. I have taken alot of bolts apart that have been in place for many years and heat always works but we use oxy/actelyne. Like the old saying goes "if it breaks then it needed to be replaced anyway"!

LOL, yep, it is a screw in a gun and while I *may* end up using a slight bit of heat, the hot wrench isn't an option. I'm just shocked Kroil hasn't done the job yet.

I would try soaking it good and try to tighten the screw. Maybe if you can work it back and forth a little at a time eventually it will come loose just be carefull not to bust the top of the screw off and make sure you have a proper fitting screwdriver. I use Kroil for everything it's expensive but luckily when I go for turnarounds at the local refinerys there are cases and cases of that stuff laying around, needless to say I have a lifetime supply of it! Good luck!

Submerge gun in kerosene, forget about it for at least a week. Then use the penetrateing oil.

I've tried tightening it, but like I said, it won't budge in either direction. No problem with the proper fitting blade, one of my Brownells bits fits perfectly.

Never thought about Kerosene before Kroil, that may be worth a shot.

Keystone #1, if you can find it.

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and what his trumpet saith

best stuff i ever found was at home depot, its called pb penetrating catalyst or oil. works on most things in a few seconds.
its in a funny lookin can with a yellow top.

I worked in a large tool & die shop, lots of stuck nuts and bolts. Some of the guys liked PB Blaster or Nutzi-lube, I couldn't see any improvement over Kroil. I always succeeded with Kroil, sometimes prolonged soaking and/or the judicious application of heat was necessary. But Kroil always did the job for me.

Kroil is top shelf, but I've also had success with Breakfree CLP.

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James L. "Jim" Rhiner

If you can support the gun in the proper position, get the best - fitting screwdriver in the screw and tap on the end of the screwdriver handle with a small hammer, while applying some gentle twisting force to the screwdriver. Sort of what you would get with an impact driver. You may have to try in both directions, but this usually works on some very stubborn screws. I prefer this method over using an actual impact driver.

Myron

Somewhere on the 'net I read that a mix of acetone and ATFluid was the best. I personally like Kroil.

If you use the acetone, pls do not use heat, and do maximize ventilation.

Good luck,

Dyson

The very best penetrating oil I have used is relton R7 in a spray can. 30 years ago when I worked as a Homelite factory mechanic I used this product on concrete vibrators, it was the only product that worked for us. Not sure it is still available.

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NRA Endowment member

Regarding anoblefox's suggestion, contact the company directly at Welcome to Relton Corporation

In regards to acetone and ATF fluid, this has been circulating through email for some time, my personal test have shown it to be rather accurate:
bored350

If penetrating oil is so good...how do they keep it in the can?
LOL.

Interesting......thanks!

Take a little puddy and make a ring around the screw,
Get some oil in there and make a puddle.
Allow to set, This way it wont run away.
Interesting about acitone and ATF,
I will have to remember that

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Need 1/2 moon Chiefs special

I used this home mix (1/2 acetone 1/2 ATF) on a rusty roller chain, to see what would happen, worked well. Dont know about using near any plastic or nylon.

Marvil Mystery oil.... soak it in it overnight..

Bob

Don't overlook the possibility of a thread locker being used,,especially since you say there is no rust present.
Some of the thread sealants are meant to be undone with heat and penetrating oils won't touch them. I've also run accross screws being soft soldered into place a few times.

I would also try touching the tip of a soldering gun to the screw head for a few seconds before attempting to turn it out. There may be some Loctite on the screw and the heat may soften it up enough to remove it.

I know of a certain screw that will give the acetone/ATF mix a good trial! BIL didn't know that he needed to pull the nipple set screw and nipple off of his Hawken muzzleloader when he cleaned it. That set screw is stuck! So far even Kroil hasn't worked. Next time we get together with my wife's family we'll have to give it a try. Thanks for the tip!