Jaw screw is stuck. Need guidance

[olskool]

i have been a professional transmission rebuilder for 45 years and a mechanic even longer. over the decades i have used everything in the book to get frozen bolts loose. as far as "penetrating oil" one that really dose anything is the old liquid wrench, it dose or can penetrate, kerosene is a close second, i have never saw Kroil or other fancy oils pernitrate anything but your wallet. then there is heat, that works. but it can harm things when you are talking about a gun part, be carful with that,,,,,,,,,,,,,

 

[toot]

Picked up an old Fowler. This screw will NOT budge. I’ve sprayed it with PB blaster and have lightly used a hammer. My drill won’t even get enough torque. But I haven’t put it on it’s strongest setting as I’m worried I’ll break it or something.

I do not want to keep forcing this. Any ideas ?!View attachment 81876

apply heat with the PB BLASTER. worked for me.

 

[toot]

try break fluid, let it soak.

 

[Jakeytoo]

I’ve had that happen with mine, not quite to that extent.
That’s why I prefer the jaw screw with a hole through it as well as the screw slot. Heck of a lot easier to loosen or tighten to change a flint. Safer too.

 

[Dennis A.]

put the whole thing in the freezer overnight, then apply heat at the correct place

 

[Newtire]

Try wrapping it with heavy cardboard and clamp on some vise grips. Then lightly tap the vise grip. This after soaking in your favorite solvent, heating etc. A guy I worked with would get out impossibly stuck exhaust bolts by heating them cherry red with an acetylene torch, letting them cool, & they just unscrewed easily after that. All kinds of ways really.

 

[Relic shooter]

As others are recommending soaking the lock in a 50/50 mixture of acetone & auto transmission fluid overnight & all of the lock's screws should easily come out. I've used this method for years to service & protect the screws on my original firearms.

 

[TheTyler7011]

As others are recommending soaking the lock in a 50/50 mixture of acetone & auto transmission fluid overnight & all of the lock's screws should easily come out. I've used this method for years to service & protect the screws on my original firearms.

Will the acetone ruin the patina?

 

[SDSmlf]

Will the acetone ruin the patina?

If it does, your ‘patina’ is just crude on the metal surface.

 

[gustrolland]

I picked up PB blaster. It is soaking as I type this. Is that adequate or does Kroil really work much better

Kroll works great, and also diesel fuel works even a touch better and even better if you can get some bio diesel.

 

[ZUG]

put the whole thing in the freezer overnight, then apply heat at the correct place

Dennis is correct for the size of the part I would do as Dennis says but I would first soak the whole lock in a penetrating oil for 3 to 5 days first then cold then heat.

 

[Celticstoneman]

Soak it in kerosene for about 3 days, never understood why all the fuss over kroil and those sort of expensive penetrants, a half gallon of kero 2-3 dollars in a sealed container will well out last all that other stuff.

I have never used anything else. Always works.

 

[smoothshooter]

Picked up an old Fowler. This screw will NOT budge. I’ve sprayed it with PB blaster and have lightly used a hammer. My drill won’t even get enough torque. But I haven’t put it on it’s strongest setting as I’m worried I’ll break it or something.

I do not want to keep forcing this. Any ideas ?!View attachment 81876

From the outside, the screw does not look that bad.

Have you tried heat?
Also, there is the possibility someone glued the screw in with some high-temp epoxy in the past.

 

[user 34300]

The tumbler screw? Fix the screw slot. Peene the slot back into shape with a tiny ball peen hammer. The lock is stripped? If not make it so. Only use a screwdriver that fits the slot perfectly. This a good time to get a Wheeler screwdriver set.

Do you have a compelling reason to remove the cock? Sometimes it is good to stop digging. It looks like a CVA. It may not respond well to being messed with. If the works it is a good idea to leave them alone.

It could be that someone used red loctite on the screw threads. IN that case heat he screw head with a 00 tip on an oxyacetylene torch for enough time to cause the screw to go blue. It should unscrew fine after that . Use a screwdriver that fits.

The cock clamp screw? Heat it with a propane torch and dunk in penetrating oil. If you know someone with an ultrasonic cleaner use that. Overnight in solvent will work it loose.

 

[ord sgt]

Old gunsmith trick, soak the screw in Coca-Cola for several days. It should break free.

 

[SDSmlf]

Do you have a compelling reason to remove the cock?

OP and thread title was about stuck jaw screw. No way to clamp a flint in place with a stuck jaw screw.

 

[ohio ramrod]

I have had very good results with kroil and hair drier heat. But have also had good results with ATF and acetone.

 

[TheTyler7011]

The tumbler screw? Fix the screw slot. Peene the slot back into shape with a tiny ball peen hammer. The lock is stripped? If not make it so. Only use a screwdriver that fits the slot perfectly. This a good time to get a Wheeler screwdriver set.

Do you have a compelling reason to remove the cock? Sometimes it is good to stop digging. It looks like a CVA. It may not respond well to being messed with. If the works it is a good idea to leave them alone.

It could be that someone used red loctite on the screw threads. IN that case heat he screw head with a 00 tip on an oxyacetylene torch for enough time to cause the screw to go blue. It should unscrew fine after that . Use a screwdriver that fits.

The cock clamp screw? Heat it with a propane torch and dunk in penetrating oil. If you know someone with an ultrasonic cleaner use that. Overnight in solvent will work it loose.

Heat is what I will be doing.

The weapon is an early 18th century piece, but was restored a good bit

 

[oldwood]

Whatever you do to get this resolved , once the screw is free , get a tap and die to fit and chase the threads . Some unlucky fellow might have "cross threaded " the bolt. Metric threads are fine , "not coarse" and perhaps prone to mishap.

 

[Reno]

I have to agree with several here, Let it soak and soak and soak, I know how these things are you want it done ASAP and it just gets under your skin that it wont budge. But let it soak, submerged, and forget it for several days, Take it out, brush off the crud with a brass brush or a toothbrush. If it does not move soak it some more. Then try some heat, but soaking will do wonders in my opinion.