Modifying A Fishtail Backspring ?

[Billyfish]

Bill, I have a couple of fishtails that have a ridiculously narrow tab; they're both picklocks. I would need fingernails of steel to actually lift the tab to release the blade to close them they are that narrow. I have to use a popsicle stick to lever the tab up so that the pin can be released.
Can these backspring tabs be modified (widened) to make them more useable without destroying the temper of the spring?

[Bill DeShivs]

No, but the backsprings can be ground down and repolished.
Thinning them down weakens them.

[JulesVane]

I do agree these fishtail picklocks are a stinker to pick the locks. Is Billyfish referring to welding some metal on to the lock tabs to widen them, to get a finger under them easier? I know nothing about welding, myself. Not sure if he's referring to modifying the whole backspring, or just the lock tab itself(?). I have a problem of getting a grip on the little lock tab to pick it.

[Billyfish]

I do agree these fishtail picklocks are a stinker to pick the locks. Is Billyfish referring to welding some metal on to the lock tabs to widen them, to get a finger under them easier? I know nothing about welding, myself. Not sure if he's referring to modifying the whole backspring, or just the lock tab itself(?).

Yeah, that's what I meant; can the tab be altered to make it wider so I can get a bit of a more secure grasp on it?
As it is I've got to use something to lift the spring.

[Killgar]

Something I've done on a few knives is to drill a few small holes through the largest areas of the lock head and pin a tab on (pics below). Sometimes I've used screws instead of pins. I used a carbide drill bit to make the holes. The hardness/heat treat of the lock wasn't affected.

Looking at your your knife, and the curve of the bottom of the bolster, I have to wonder, is there any chance the bolster acts like a swivel bolster to unlock the knife?

This first knife was a 9" Frank Beltrame that I rebuilt. Thumb tab pinned to the lock.






These pics show a pair of manual stilettos. They both started out the same (the one with red wood handles is mostly stock except for the thumbstud I added). I added a wrap-around thumb-press lock-release to one using screws to attach it to the lock head.







This is not intended as a solicitation. I don't work on other peoples knives. Just offering a suggestion.


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[Bartlow]

I think you could probably solder something on the existing tab also. Tom Wright https://www.youtube.com/user/tommyw68/videos shows knives he customized and some are picklocks and most have a decoration soldered to the lock tab. While solder is not the same as a weld, it also requires much lower heat. It also allows joining of dissimilar metals, so the piece soldered onto the lock tab need not be made of steel. I can imagine a weld could also be done without ruining the temper of the backspring, but the person doing it would have to have knowledge and the welder to pull it off.

If the knife were mine i would leave it alone and consider the small lock to be part of its charm If I needed a knife that had a more usable lock, I would buy one.

[Bill DeShivs]

The tab can be carefully forged wider. A larger tab can be put on top of the existing one. The bolsters can also be cut down a small amount.
The easiest thing is to just grind down the backspring a little and refinish it.
Anything else would probably require disassembly.

[Billyfish]

Thanks gentlemen; some ideas to ponder.

[Fishtail Picklock]

I love that Fishtail Picklock. Given the popular size, they're great in a belt sheath. If they're kept sharp, they are useful tools. (God, help me, i love the older designs).

: If you could disassemble the knife and give it an old-fashioned octagonal locking tab, would it prove advantageous?

[Bill DeShivs]

Not without making the tab bigger first.

[Fishtail Picklock]

Not without making the tab bigger first.

Yes, sir.
I would want to see the knife disassembled and the backspring (and/or kickspring) in order to strengthen the locking mechanism. This would make the knife even more usable. (What a novel idea!).

[Bill DeShivs]

I worked on a whole bunch of the Dibon fish knives when they came out.
Many had ill-fitting parts and backsprings too heavy.

The only way to correct the problem without disassembly is to thin and refinish the backspring.

Adding a tab, welding, or forging the tab larger requires at least the backspring pin to be removed and preferably the rear bolster pin removed also.
It's not difficult, but it takes more time.

[Billyfish]

I have a '50's Eig 11" picklock that seems to have a short gentle and shallow downward curve to its backspring that starts behind the bolsters and then lifts back up to even with the liners. The knife is 60 odd years old and is much easier to 'pick'.



I doubt it had been modified after purchase, could it have come that way from the maker for just such a reason?

[Bill DeShivs]

It's possible.

[Fishtail Picklock]

That EIG Picklock is very nice. What a wonderful piece from an earlier time!

Thanks for sharing.