Relaxing Springs

L

leghog

Joined
Aug 10, 2013
Messages
8,038
12 days ago I picked up an approximately 65 year old Robeson made KaBar scout in nearly like new condition. The condition has to be because other than the main blade all other tools were nearly impossible to open and needed tools to open one. That was also the reason for the great price.

For the last 12 days I've left all tools half open putting maximum stress on the springs. Hoping to relax the springs without breaking them. It worked. The tools can be opened without assistance using only the nail nicks.

Happy camper here.

Kabar%2520Scout.JPG
 
I'm happy for you, too, leghog! Sometimes I've had to leave the springs stressed for a lot more than a week, but it usually works in the end. Now you got a beauty- hardly looks used at all. :thumbsup::)
 
Nice find! On some difficult to open knives sometimes it just needs to be opened and closed a bunch of times. Glad you got it working!
 
Thanks for the hint.
I've got an old case canoe which has a very strong opening on the main blade.
It became better after some opening/closing, but still hurts my thumbnail.
Before I will let it open for a while, is it really dangerous for the spring?
 
I'm glad that it worked out for you. It has worked for me on several occasions. A lot of times I will just leave it under stress while I sleep and then put it in my pocket the next morning if it's something I plan on carrying. I have had one or two that just needed to be left under stress for days at a time. I have never had any detrimental effect by doing this.
 
Ernie1980 said:
Nice find! On some difficult to open knives sometimes it just needs to be opened and closed a bunch of times. Glad you got it working!
Click to expand...
Excepting in this case on a scale of 1 to 10 with ten being the toughest, the can opener/cap lifter was a 30 and the awl was a 20. Only way to open the can opener/cap lifter was to open all other blades then use a chop stick under it to help lever it out.
 
I find all that truly interesting. I have owned hundreds of Robeson knives and handled thousands, probably.

I have never encountered a Robeson knife with springs so stiff, I could not open the blades.

I'd be more inclined to think there was binding between the tangs and the frame.

Penetrating oil and exercise might have worked just as well.
 
This is why you always set your torque wrenches back to zero. The smaller and thinner the spring the more susceptible it is.

Once you get to something that's about the size of a pistol mag spring it becomes the cycles that have more of an effect vs. a load/no load situation.
 
CNoyes said:
I find all that truly interesting. I have owned hundreds of Robeson knives and handled thousands, probably.

I have never encountered a Robeson knife with springs so stiff, I could not open the blades.

I'd be more inclined to think there was binding between the tangs and the frame.

Penetrating oil and exercise might have worked just as well.
Click to expand...

If there was something binding between the tangs and frame, it magically disappeared. Exercising the pulls wasn't an option as I didn't exaggerate the difficulty of the pulls. I literally tore a nail off and impaled the quick. That took a week to heal.
 
Glad that actually worked for you.

I have tried it with decent results, but it was temporary, like the spring steel had a memory.

But now I may try again on a mint, Case half whittler ( 70's vintage ) that is almost impossible to open the pen blade.
 
Glad that worked for you, and thanks for sharing this.

The George Wostenholm I*XL Duncan sent me could certainly use about a week of this to make it a bit easier to open.
it did eventually get a bit easier to open to the point that I can just barely pinch it open 9/10 times and it doesn't really hurt my fingers too much, but I still normally use the hooked pick I made and wouldn't mind not having to.

Boy I wish I knew about this when I first got the knife because I could've been leaving it partly open each night till I got it where I wanted, that is if it will stay open between half stop and open.
 
You know, our automobiles sit in our driveways, day after day, month after month, for years with thousands of pounds of stress on the leaf springs and yet the car does not get appreciably closer to the ground.
 
I tried this on an older Fightn Rooster stockman/sheepfoot for about a month with no discernible difference in pull. I'm just trying to "use" it in now.--KV
 
leghog said:
Other than the main blade the scout was unusable.
Click to expand...
I have a Bower Brand Barlow that came to me in like new condition, and I quickly realized why the knife had never been used. It was a bear trap nail breaker, no amount of flushing and working the joints did any good to make it easier to open. I left that knife with the blades open to maximum deflection on the springs for a couple weeks, and yes, it did weaken those springs and now the knife has a more normal pull.

As it was it was a totally useless paperweight, and I really didn't care one way or the other how it would turn out, because in its original state it was useless to me. I came to enjoy that knife and got some use from it after the spring stretch treatment. As a last resort, it's a good option to try and make a knife useable, vs a thing that sits in a box, getting the stink eye lol.
 
CNoyes said:
You know, our automobiles sit in our driveways, day after day, month after month, for years with thousands of pounds of stress on the leaf springs and yet the car does not get appreciably closer to the ground.
Click to expand...
the larger the spring the less prone it is. But I do know folks with expensive race bikes who will have the suspension unloaded with the bike on jackstands just to not sack out the springs.
 
Probably depends on the specific knife/spring as to whether it works or not. There seems to be mixed results using this method. I tried overstretching the spring with a small screwdriver on my stockman but it didn't help. I even put it in a padded vice and opened and closed it about 500 times. It has gotten maybe 10% easier over a years use.--KV
 
sitflyer said:
I have a Bower Brand Barlow that came to me in like new condition, and I quickly realized why the knife had never been used. It was a bear trap nail breaker, no amount of flushing and working the joints did any good to make it easier to open. I left that knife with the blades open to maximum deflection on the springs for a couple weeks, and yes, it did weaken those springs and now the knife has a more normal pull.

As it was it was a totally useless paperweight, and I really didn't care one way or the other how it would turn out, because in its original state it was useless to me. I came to enjoy that knife and got some use from it after the spring stretch treatment. As a last resort, it's a good option to try and make a knife useable, vs a thing that sits in a box, getting the stink eye lol.
Click to expand...

kvaughn said:
Probably depends on the specific knife/spring as to whether it works or not. There seems to be mixed results using this method. I tried overstretching the spring with a small screwdriver on my stockman but it didn't help. I even put it in a padded vice and opened and closed it about 500 times. It has gotten maybe 10% easier over a years use.--KV
Click to expand...
If a knife is really unusable, my last ditch technique is to take a small jeweler's needle file to the inside corner of the tang- the one that pushes against the spring on opening. This doesn't effect the spring's strength in the open position, just how far it has to lift on opening.
 
I picked up a Queen folding hunter off the bay and it was a bear to open both blades. I left the blades in the half open position for a year and it is now about a 7.
 
You must log in or register to reply here.
Back
Top