Freeing a frozen nut (aluminum) on steel threads

Richard

Richard

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Ack...city life
I've my dad's USMC issue M-43 entrenching tool. It features a shovel and a pick that are collapsible. There is an aluminum nut threaded onto a steel barrel which is frozen in place. I've attempted to free the nut by penetrating oil, heating the nut, or heating the barrel. None of my attempts have been successful. I am open to ay advice to help me accomplish freeing the nut.
I do wish to avoid cutting into the nut.
 
I've not heard of the 50/50 solution which Tim suggests. I will give it a try.

I have also used PB Blaster. No joy.

I suspect part of the problem is the tool has been spray painted.
 
RotorAndWing said:
PB Blaster.
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Recently “Machinist Workshop Magazine” did a test on penetrating oils. Using nuts and bolts that they ‘scientifically rusted’ to a uniform degree by soaking in salt water, they then tested the break-out torque required to loosen the nuts. They treated the nuts with a variety of penetrants and measured the torque required to loosen them.

This is what they came up with:
Nothing: 516 lbs
WD-40: 238 lbs;
PB Blaster: 214 lbs;
Liquid Wrench: 127 lbs,
Kano Kroil: 106 lbs
(ATF)/Acetone mix (50/50): 50 lbs.
Click to expand...

Mouse Milk wasn't in the test but it's amazing stuff.
 
Richard said:
Yes, as much as I could. In fact, the threads are in pristine shape, ready to accept the nut when it agrees to budge. :)
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The "as much as I could" bothers me a little bit. A wire wheel will remove everything as will a chemical attack. Make sure the paint is gone so the magic stuff Tim suggests can penetrate.
 
Clark1961 said:
The "as much as I could" bothers me a little bit. A wire wheel will remove everything as will a chemical attack. Make sure the paint is gone so the magic stuff Tim suggests can penetrate.
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I meant I cannot get to the threads under the nut. Even if that paint is dissolved it is still clogging those threads, no?
 
Richard said:
I meant I cannot get to the threads under the nut. Even if that paint is dissolved it is still clogging those threads, no?
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Dunno. I tried to type a bunch of stuff about surface tension and wetting angle but who knows with spray paint. Prolly a real mess.

Be patient, use heat and Tim's magic fluids. Be patient.
 
Clark1961 said:
Dunno. I tried to type a bunch of stuff about surface tension and wetting angle but who knows with spray paint. Prolly a real mess.

Be patient, use heat and Tim's magic fluids. Be patient.
Click to expand...

RE: 'wetting angle', defined as that surface which is directly affected by application of surfactant/liquid/penetrant? Please provide definition.
 
I've tried applying penetrant at various temperatures, including applying heat through butane torch, to induce 'suction' of penetrant into frozen threads. No desired yield so far.
 
Richard said:
RE: 'wetting angle', defined as that surface which is directly affected by application of surfactant/liquid/penetrant? Please provide definition.
Click to expand...

Wetting angle is a measure of the contact angle, measured through the fluid, of a fluid and a surface. Going from memory but that's pretty close.

If the angle is greater than 90* then the fluid is non-wetting and tends not to spread (energy in some form is required to spread the fluid). Wetting fluids have a low angle and tend to spread.

With a threaded system, the extent of spread will depend on wettability of the paint. It will also depend on thread design since the clearances within the thread will impact the extent to which the paint penetrates. Since I don't have a clue about the thread used on entrenching tools I have to say, " I dunno" about the penetration. Surface tension will also play a role since it will also influence spread of a liquid. It gets complicated...
 
Clark1961 said:
Wetting angle is a measure of the contact angle, measured through the fluid, of a fluid and a surface. Going from memory but that's pretty close.

If the angle is greater than 90* then the fluid is non-wetting and tends not to spread (energy in some form is required to spread the fluid). Wetting fluids have a low angle and tend to spread.

With a threaded system, the extent of spread will depend on wettability of the paint. It will also depend on thread design since the clearances within the thread will impact the extent to which the paint penetrates. Since I don't have a clue about the thread used on entrenching tools I have to say, " I dunno" about the penetration. Surface tension will also play a role since it will also influence spread of a liquid. It gets complicated...
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You must be, or was, acting as an engineer. Engineers always make the easy complicated. :rofl:

Great, so now I know what is going on but it doesn't help to solve the problem.

So, what if I submerge the piece into a penetrating liquid and let is set for X time?
 
Richard said:
You must be, or was, acting as an engineer. Engineers always make the easy complicated. :rofl:

Great, so now I know what is going on but it doesn't help to solve the problem.

So, what if I submerge the piece into a penetrating liquid and let is set for X time?
Click to expand...

I are an enginear (stil can't spel).

Soaking sounds like a darn good idea. If soaking isn't practical then use repeated applications over several days. Heat is always good since energy is needed to break the chemical bonds of rust.
 
An aluminum nut on a steel bolt is about as bad as it gets. You have dissimilar corrosion in the threads of the bolt, and if it's been there for many years it's really locked in.

Try the 50/50 acetone and ATF mix, soak for several days.
 
Force it, if it breaks it needed to be replaced anyway.....
 
Short of using a big enough hammer - the elegant solution - I suggest an electrolytic bath.
Look it up on the net. Nothing more than Arm & Hammer Washing Soda and a 12 volt battery, some wire and a piece of metal.
Now having said that, having aluminum on steel in the bath does raise the probability that you wall also eat some of the aluminum nut - which at this point is expendable, so (shrug)

The issue here is the corrosion has swelled both the steel and the aluminum threads so that you have a mechanical lock between the pieces the equal of a weld joint. Using a die grinder with a thin disk and carefully cutting into the nut so you can spread it, is how I would do it in my shop.
 
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If pb blaster doesn't do it after a few attempts,cut it.
 
Clark1961 said:
I are an enginear (stil can't spel).

Soaking sounds like a darn good idea. If soaking isn't practical then use repeated applications over several days. Heat is always good since energy is needed to break the chemical bonds of rust.
Click to expand...

RE: application of heat, alternately I have tried heating the nut and heating the barrel. No joy.

What would you suggest with respect to the application of heat? My premise in heating was any corrosion that exists between the dissimilar metals would be crushed by expansion.
 
RotorAndWing said:
An aluminum nut on a steel bolt is about as bad as it gets. You have dissimilar corrosion in the threads of the bolt, and if it's been there for many years it's really locked in.

Try the 50/50 acetone and ATF mix, soak for several days.
Click to expand...

I'll be getting some Mouse Milk and will try the ATF/Acetone solution. Which would you try first?
 
Dr. O said:
Short of using a big enough hammer - the elegant solution - I suggest an electrolytic bath.
Look it up on the net. Nothing more than Arm & Hammer Washing Soda and a 12 volt battery, some wire and a piece of metal.
Now having said that, having aluminum on steel in the bath does raise the probability that you wall also eat some of the aluminum nut - which at this point is expendable, so (shrug)

The issue here is the corrosion has swelled both the steel and the aluminum threads so that you have a mechanical lock between the pieces the equal of a weld joint. Using a die grinder with a thin disk and carefully cutting into the nut so you can spread it, is how I would do it in my shop.
Click to expand...

The alum would not survive that treatment.
 
PaulS said:
Force it, if it breaks it needed to be replaced anyway.....
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This is very distressing to me. As I wished to convey in the OP this is my dad's entrenching tool. He carried it through 2 tours in Korea (advance to the rear at Chosin Reservoir, and Pusan) and three tours in VN (Khe San, De Nang, Cam Rahn bay). It's something I wish to keep intact.
 
Richard said:
This is very distressing to me. As I wished to convey in the OP this is my dad's entrenching tool. He carried it through 2 tours in Korea (advance to the rear at Chosin Reservoir, and Pusan) and three tours in VN (Khe San, De Nang, Cam Rahn bay). It's something I wish to keep intact.
Click to expand...

Why do you need to take it apart then? Is it just the nut that is frozen or the mechanism is frozen? A picture is worth a thousand words.

Edit:

Ok, I think I found a picture on the googles... I was thinking hex nut, that's more what I would call a hand nut. I would use the PB blaster route for a few days, then get one or two strap wrenches, one for the barrel and one for the nut. Position them about 30 degrees from each other and torque the nut. You need to get some force on it to see if you can budge it. Just be careful with the strap wrenches that you don't dent the barrel, but I'm thinking if it survived all those tours it's probably pretty tough. Corrosion is tough though, it may have weakened the nut. The good news is if you do damage the nut, these tools seem readily available on ebay, you could probable find another nut.
 
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Richard said:
I'll be getting some Mouse Milk and will try the ATF/Acetone solution. Which would you try first?
Click to expand...

Try the 50/50 solution while you're waiting for the Mouse Milk to arrive (I doubt you'll find any locally...you'll likely need to order it from an online aviation retailer).

BTW, since there are many specifications for ATF these days, the one I always use is Dexron/Mercon.
 
PaulS said:
Why do you need to take it apart then? Is it just the nut that is frozen or the mechanism is frozen? A picture is worth a thousand words.
Click to expand...

That is a valid question. It is the nut which is frozen. I am unable to upload pictures at this time.

Picture several permutations

  • the tool is collapsed to be stowed in canvas pouch
  • the shovel is extended
  • the pick is extended
  • the pick and the shovel is extended
the nut is what allows for each of those.

The pick/shovel is hinged on it's own pivot. But neither can extend or collapse unless the nut is relieved from the base of the threads. As it is now the nut is fully threaded to the base. This prevents the mechanism from functioning as designed. My objective is that the tool fully function as designed.

Google USMC M-43 entrenching tool. (pick and shovel)

(Picture is generic)
 

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Having dealt with the subject e-tool frequently, I would say you have a cross thread situation that no lubricant is going to solve. A rag and a pipe wrench are your best hope. Wrap the rag around the nut to reduce the damage caused by the pipe wrench and then twist it off. Once it is off, use a chisel to smooth out any damage to the inside threads and then put it back on. I doubt the steel threads are damaged but if they are use a file on them. Once it is all cleaned up, repaint them.
 
cgrab said:
Having dealt with the subject e-tool frequently, I would say you have a cross thread situation that no lubricant is going to solve.
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Highly doubtful since this nut is likely NEVER removed from the threaded handle.

I have a tool just like this one and the nut doesn't come off unless you completely disassemble it which is rarely if ever done.
 
Richard said:
That is a valid question. It is the nut which is frozen. I am unable to upload pictures at this time.

Picture several permutations

  • the tool is collapsed to be stowed in canvas pouch
  • the shovel is extended
  • the pick is extended
  • the pick and the shovel is extended
the nut is what allows for each of those.

The pick/shovel is hinged on it's own pivot. But neither can extend or collapse unless the nut is relieved from the base of the threads. As it is now the nut is fully threaded to the base. This prevents the mechanism from functioning as designed. My objective is that the tool fully function as designed.

Google USMC M-43 entrenching tool. (pick and shovel)

(Picture is generic)
Click to expand...


Richard,

I added this to my post above, I don't know what you have been trying to turn it with, but I think you need to get a tool on it for extra torque, if it moves, just be patient and move slowly. It should give you a little warning before you do damage, just don't push it that far. But honestly, you may have to muck up the nut to get it off if you can't move it.

Edit:

Ok, I think I found a picture on the googles... I was thinking hex nut, that's more what I would call a hand nut. I would use the PB blaster route for a few days, then get one or two strap wrenches, one for the barrel and one for the nut. Position them about 30 degrees from each other and torque the nut. You need to get some force on it to see if you can budge it. Just be careful with the strap wrenches that you don't dent the barrel, but I'm thinking if it survived all those tours it's probably pretty tough. Corrosion is tough though, it may have weakened the nut. The good news is if you do damage the nut, these tools seem readily available on ebay, you could probable find another nut.
 
I've had the damn thing soaking -fully submerged- in PB Blaster for two weeks now. Each day I would bring it inside the house to avoid nighttime dew. I have the extended blade of the shovel clamped in the jaws of a 25# vise and have applied 20" Crescent wrench (the real, bonafide Crescent, not some cheap ass imitation) and cannot even get the nut to give any bit. I seriously doubt a breaker bar will work any better. At this point my only hope is breaking the bond through chem or thermo.

Hope against hope I don't have to cut the damn nut. But if I was in a fox hole crawling under a dead body to avoid a bullet that is exactly what I would do.

It just breaks my heart that is what the old man had to do and I cannot even free a frozen nut. In his honor. Do you see?
 
Sorry, I got carried away. It's just one of the few tangible things I have left. The man was very particular about maintaining his equipment. It rubbed off on us. I reckon I've become so absorbed but for reasons which have nothing to do with that stupid tool.
 
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Richard said:
Sorry, I got carried away. It's just one of the few tangible things I have left. The man was perfidious about maintaining his equipment. It rubbed off on us. I reckon I've become so absorbed but for reasons which have nothing to do with that stupid tool.
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It's all good.
 
Richard said:
Sorry, I got carried away. It's just one of the few tangible things I have left. The man was perfidious about maintaining his equipment. It rubbed off on us. I reckon I've become so absorbed but for reasons which have nothing to do with that stupid tool.
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I get it. I have many of my grandfather's tools.

As a previous poster suggested: impact. Tap nut all the way around.

Then my addition: once you have the crescent wrench well set, tap the handle of the crescent wrench with a metal hammer, gently. The sharp impact will some time break things loose. Also try tightening first. Sometimes it'll move one way but not the other.

John
 
Just last night my otherwise intelligent brother did something idiotic. Just now he showed me the results. Sumbitch, he used steel Channel Loks on recalcitrant aluminum nut without padding. It's so awesome the nut now has jaw marks on it and bits of the raised surfaces are shredded. I'm thinking mebbe he needs to be soaked.

He says, in his defense, he didn't believe me that the nut is alum. He thought it was steel. If you ask me he picked a helluva way to find out.
 
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