I was in the process of removing old rings and bases from a Weatherby Vanguard (had not been off the rifle in over 20 years); three of the hex screws for the bases came out without difficulty, but the fourth one would not move and I ended up rounding off the inside of the hex surface. It looked like I was stuck, but I thought I'd give Kroil a try before going to outside help. I dabbed Kroil around the edge of the screw and let it soak in for about 20 minutes.

Since the hex slot was too rounded for a regular hex bit or key, I took a Torx bit that was almost small enough to start into the top of the screw and lightly tapped it in a little way with a small hammer. The bit with handle turned the screw right out of the receiver. Other solutions may have worked, too, but in this case I think that the Kroil did the trick.

I think it was tapping on the screw.

Often on machinery, cars etc a stuck bolt will come free after you give the bolt a wack on the head with a good size hammer.
It must break the bond of rust.

Yeah, its good stuff. I've used it in in industrial applications to remove stubborn nuts, bolts and studs. You swerved into a great technique. That is to give the stuck screw a good rap with the hammer via a tight fitting bit. When screws and bolts are over-tightened, the threads stretch a bit and really jam hard when you try to remove them. By hitting the top of the screw you re-compress the threads and many times release the screw threads from tension and allow the screw to be removed easily.

Kroil is awesome stuff. Best thing for removing 100 year old mauser barrels. I think what makes it so good is the Benzine. Nasty lung cancer causing stuff, but it's the best thing there is for breaking things apart. Just follow the precautions on the can, use common sense when applying it, and no one should have any worries. I think benzine may have been used in break cleaner up until it's link to lung cancer was determined.

Never tried Kroil but a mixture of AT Fluid and
Acetone about 50-50% works great. --- John

retired from power co, we had to change out transformers and other pole mounted equipment that had been out in the weather 50 plus years, kroil will get-er- done, but the tapping with the hammer can't be discounted.

Never used it; was on a bear hunt once and my friend pulled out his 416 and began applying something that I could smell 10 feet away; very strong smell. I asked him what it was and he said "Kroil". I said he would scare off any bear within a mile. He never saw a bear all week. I saw 2.

Yes, now that I am reminded, the tapping as well as penetrating oil is part of the reason for breaking loose. Just glad I don't have to pay someone else to fix it.

Back in my days on M60 tanks, we would have bolts and shock bearings seize up, often remedied with soaking in Coca Cola, heating with a torch and smacking with a hammer. They were just a little bigger than scope mount screws.

Brake fluid works about as well The tapping more than likely would face worked alone

Liquid Wrench almost always works for me, big or small jobs.

quote:

Originally posted by John303.:
Never tried Kroil but a mixture of AT Fluid and
Acetone about 50-50% works great. --- John

I get the ATF but acetone is so volatile I doubt it helps much. Wouldn't be the first or last time I was wrong though. I am curious as to why the acetone? Just as a thinner? Or does it act as a second solvent here and not evaporate as fast because of the admixture?

I suspect the actone is a carrier: it gets the ATF down to where it needs to go and then evaporates, leaving the ATF to do the work...

quote:

Originally posted by Bobster:
You swerved into a great technique. That is to give the stuck screw a good rap with the hammer via a tight fitting bit. When screws and bolts are over-tightened, the threads stretch a bit and really jam hard when you try to remove them. By hitting the top of the screw you re-compress the threads and many times release the screw threads from tension and allow the screw to be removed easily.

This is how an impact tool works, saved me from trouble when getting an ancient Honda Super 90 apart to change the clutch disks.