Stripped screw on new Sebenza 25

[nyefmaker]

I would try any of the above right AFTER soaking it (not the blade) in very hot water..I mean boiling. Use a pair of oven mitts if you have to. It's simple chemistry or physics (depending on what major you are) and is a trick that I use all the time to try to loosen metal up.

Will definitely solve lock tight issues...even though this isn't th case...just FYI.

While I knew heat makes metal expand and that boiling water would loosen locktite, I never figured boiled water would be hot enough to make the metal expand enough to loosen a tight screw. Learn something new everyday, or everynight at this point.....lol.

 

[Livefreeordie92]

Not the first time I've seen or heard of that. CRKs hardware in my experience is somewhat soft compared to say Strider or Zero Tolerance. Its not horrible, it just seems to strip much more easily in my experience. They're CS is great though.

 

[Sharpski]

While I knew heat makes metal expand and that boiling water would loosen locktite, I never figured boiled water would be hot enough to make the metal expand enough to loosen a tight screw. Learn something new everyday, or everynight at this point.....lol.

Ha Yea, I actually and to do this on a zaan with the old pivots. I put too much locktite on it my accident and dint wipe enough off and it got pretty stuck. Especially when trying to work with those clumsy plastic pivot tools. After snapping one peg off one of them trying to just crank it, I placed it in hot water and wore winter gloves on one hand and the pivot tool in the other. I managed to get it saving myself $20 in shipping to CRK. It especially works well on cold metal that has condensed in the cold (which is normal). I worked as a butcher for a few years and in the morning we would put together the grinder and we kept it in the cooler room so my the end of the day when it was time to clean it it was a bear to disassemble. Spraying hot water on it expanded the metal enough to be able to loosen.

I must say the expansion of the metal is more on a microscopic level and definitely not permanent. Metal or any material is in constant state of microscopic expansion and constriction. Heat and cold being the most obvious factors. Ever notice that a sebenza that has been in your pocket all day it is just a bit smoother than when you first open it before you start the day? Same principle

Live free or die, this is a first I have heard of it as well. I always felt like I had to be careful with like spyderco or ZT screws but not so much with CRK. What a bummer!

 

[nyefmaker]

Ha Yea, I actually and to do this on a zaan with the old pivots. I put too much locktite on it my accident and dint wipe enough off and it got pretty stuck. Especially when trying to work with those clumsy plastic pivot tools. After snapping one peg off one of them trying to just crank it, I placed it in hot water and wore winter gloves on one hand and the pivot tool in the other. I managed to get it saving myself $20 in shipping to CRK. It especially works well on cold metal that has condensed in the cold (which is normal). I worked as a butcher for a few years and in the morning we would put together the grinder and we kept it in the cooler room so my the end of the day when it was time to clean it it was a bear to disassemble. Spraying hot water on it expanded the metal enough to be able to loosen.

I must say the expansion of the metal is more on a microscopic level and definitely not permanent. Metal or any material is in constant state of microscopic expansion and constriction. Heat and cold being the most obvious factors. Ever notice that a sebenza that has been in your pocket all day it is just a bit smoother than when you first open it before you start the day? Same principle

Live free or die, this is a first I have heard of it as well. I always felt like I had to be careful with like spyderco or ZT screws but not so much with CRK. What a bummer!

Very interesting and informative post. Thanks

 

[Haze]

Thermal expansion depends on the alloy as well as the temperature. Heat does indeed do interesting things to molecules but thermal expansion is more than just a molecular thing on a microscopic level. We have all heard the creaking of a metal roof or gutter pipes on a hot day, that is thermal expansion. There is actually a minimal but measurable difference in volume as the temperature increases.
When you heat a bolt on your car the heat breaks a bond that has or was formed in one way or another. In some cases the expanding metal may well free the bolt as it expands and contracts during heating and cooling, but more usually the heat degrades the bonding material and that is how it is released.
Our knives are not even close to needing heated up to remove a screw or pivot and it is purley the use of loc-tite that would require heating. The heat degrades the bonding material and allows the screw to be removed, there is nothing more going on than that. One can also release the bond with forced pressure like a hammer tap on a driver, but that is not a good idea on knife hardwear as they tend to be on the soft side and are rather small screws so easy to deform or even destroy.

 

[Sharpski]

Thermal expansion depends on the alloy as well as the temperature. Heat does indeed do interesting things to molecules but thermal expansion is more than just a molecular thing on a microscopic level. We have all heard the creaking of a metal roof or gutter pipes on a hot day, that is thermal expansion. There is actually a minimal but measurable difference in volume as the temperature increases.
When you heat a bolt on your car the heat breaks a bond that has or was formed in one way or another. In some cases the expanding metal may well free the bolt as it expands and contracts during heating and cooling, but more usually the heat degrades the bonding material and that is how it is released.
Our knives are not even close to needing heated up to remove a screw or pivot and it is purley the use of loc-tite that would require heating. The heat degrades the bonding material and allows the screw to be removed, there is nothing more going on than that. One can also release the bond with forced pressure like a hammer tap on a driver, but that is not a good idea on knife hardwear as they tend to be on the soft side and are rather small screws so easy to deform or even destroy.

I was not suggesting using heat to take out normal screws. There should be no need for that. It's is just a trick when you need a little extra help. Much like adding length or diameter to a screw driver. Bonds are usually not outright destoried in that the energy in the bond when broken is only simply displaced and or changed. We all know energy is not created or destroyed.

Locktite is likely an ester compond probably with some free carbonyl groups, and without going into too much organic chemistry, these allows for a lot of "bond shifting". This bond shifting occurs during curing but also creates a situation were the cured product will decrease in strength with time. This plotted line would have a predictable slope. Heat would decrease the slope of this line by speeding up the reacting by decreasing the activation energy of this reaction, much like an enzyme or catalyst, and probably would not actually outright destroy these bonds. Although your phycial torque may. It's an interesting thought experiement but with out a specific data sheet and actualy experimentation I cannot say for sure. I do know that heat, unless extreme, lowers the activation of engery for a given reaction and allows it to occur faster or with less external energy and doesn't really break bonds. This is why hot water on a over locktited screw allow it to be loosened more easily.

 

[Haze]

We are saying the same thing here in that raising the temperature degrades the bonds the active chemical(s) produce and so and the adhesive properties they create in cured loc-tite are deminished. In short, heat makes the loc-tite lose its grip.

 

[nyefmaker]

I was not suggesting using heat to take out normal screws. There should be no need for that. It's is just a trick when you need a little extra help. Much like adding length or diameter to a screw driver. Bonds are usually not outright destoried in that the energy in the bond when broken is only simply displaced and or changed. We all know energy is not created or destroyed.

Locktite is likely an ester compond probably with some free carbonyl groups, and without going into too much organic chemistry, these allows for a lot of "bond shifting". This bond shifting occurs during curing but also creates a situation were the cured product will decrease in strength with time. This plotted line would have a predictable slope. Heat would decrease the slope of this line by speeding up the reacting by decreasing the activation energy of this reaction, much like an enzyme or catalyst, and probably would not actually outright destroy these bonds. Although your phycial torque may. It's an interesting thought experiement but with out a specific data sheet and actualy experimentation I cannot say for sure. I do know that heat, unless extreme, lowers the activation of engery for a given reaction and allows it to occur faster or with less external energy and doesn't really break bonds. This is why hot water on a over locktited screw allow it to be loosened more easily.

Who would think we would get a lesson in chemistry and science here on the CRK Forum.....? I should have paid more attention in school....LOL.