Gritty opener

wazu013

wazu013

Joined
Dec 14, 2011
Messages
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I have a Puma Duke lockback that I bought NIB a few years ago and just put it away and forgot about it. I took it out the other day for pics and found there's a gritty feel to it when I open and close it. I figured it was just hafting material so I washed it out with soap and hot water, then rinsed it with WD40 and washed and dried it again before I applied some Rem Oil to it. It's still doing the same thing. Is there something I can do above and beyond what I've already done. I'm a little nervous about sending it back to Puma for repair. Any help would be appreciated. The little bit of dirt seen in the pic on the tang is long gone.
Thanks,
wazu013
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Does the gritty feel impair the the opening of the knife? Is it just that you don't like the feeling of a gritty opening?

You've done what I would do except apply a few weeks plan of opening and closing the knife. Work the blade 25-50 times a day with a drop or two of lubricant.

I have some older knives I've done this with and had good to excellent results. It's worth a try.

Mike
 
It works just fine. The lock up solid with no wobble. I'm sitting here opening and closing it to see if it will help. I just want to smooth it out if it's possible without sending it anywhere. I figure there's a member on the BF that has a trick or two to help me out.
The grinding doesn't start until the last 1/4" before lock up. The rest of the ride is fine. What if I got some scotch brite or 0000 steel wool in there and worked it a little?
 
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I've had knives with some grit in the movement, and I would suggest the same as Mike. My newest knife came with a gritty feel and I flushed it very much like you did. Then I just sat and worked it while I was helping my kids with their homework. After opening and closing about 100 times it's now silky smooth. Those rough spots will wear down with normal use.
 
That's a shame. You have done the typical things. One of the hallmarks of the old Puma lockbacks was the "ball-bearing" walk and talk.

I wonder if there isn't something in the lock recess on the lockbar and/or the recess on the tang mucking things up? A toothpick might help dig some of that out. Or hold the lockbar open and really hose it out.
 
MarkPinTx said:
That's a shame. You have done the typical things. One of the hallmarks of the old Puma lockbacks was the "ball-bearing" walk and talk.

I wonder if there isn't something in the lock recess on the lockbar and/or the recess on the tang mucking things up? A toothpick might help dig some of that out. Or hold the lockbar open and really hose it out.
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You're right about the way all my old Puma's opened and closed. I have an old sergeant that's the smoothest opening lockback on the planet. This one is just off a little. I've done what you suggested with the wash out and I just blew it out with canned air. Now I'm working it open and closed with a drop of 3in1 oil. I'm hoping that will be the ticket.
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I have found with some knives that you need to work it back and forth a lot with the pivot submerged in the hot soapy water. Swish it back and forth, open and close a lot, while in the water. I wrap the blade several times with masking tape to prevent cutting myself and to get a good grip on the blade in the soapy water. Water as hot as you can stand it, and use a grease-cutting soap like Dawn.

Afterwards, blow it out and follow up with WD-40 to get the rest of the water out, working back and forth then too. Follow up with an oil of some kind and keep working it. I had a new GEC with a really stiff pull, to the point I almost sent it back to the dealer. But while sitting there just opening and closing (taped blade, after the rinsing) I felt something give way (like maybe a small piece of grit finally dislodged) and all of a sudden it was crisp and smooth.

That's about all I can suggest, other than service by a knifesmith or the maker.
 
I notice that my lock backs with brass liners (i.e. Buck 110) get gritty when they have sat awhile. A liberal dose of 3 in 1 and working the knife open/closed will smooth to out again for me. I think there is a chemical reaction that takes place between the SS and brass over time.
 
If opening and closing the knife under running water didn't help at all, perhaps there's a burr on the metal or a nick in the soft liner material.

I notice that my lock backs with brass liners (i.e. Buck 110) get gritty when they have sat awhile. A liberal dose of 3 in 1 and working the knife open/closed will smooth to out again for me. I think there is a chemical reaction that takes place between the SS and brass over time.
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Interesting observation. Like aluminum wheels frozen to the axles on a modern automobile...
 
Flush out the joint with mineral oil. I use a q tip and drip some in there, work the blade, keep applying more oil and wipe off the excess oil and dirt every so often. When you're done you might let it sit so more of the oil drains. Either that or clean it with soap and water, use compressed air or wd-40 to dry, then apply whatever lubricant you normally use.
 
Use breakfee or wd40 and compressed air. There could be some grit near the back lock mechanism. They typically use a spring to rebound the lock.
 
For oil, I'd pick something of lighter weight than 3-in-1. Breakfree is one, so is Quick Release, which I use; I've heard sewing machine oil (fabric store) recommended, too.

But first, I'd really work the hot-water-and-dish-soap routine, along with a long-bristle brush to clean down into the blade well and around the root of the tang where it slides against the backspring. In fact, I'd keep at it with soap and water until it opened and closed smoothly through the whole range of travel.

Pick up some old dental tools, wood coffee stirrers (Starbucks), and the like to poke clean cloth down into the crevices, like the locking-tab hole on the tang. I have also picked up a couple of my wife's orangewood manicure sticks, which are pointed and hold their shape. Great for getting gunk out of places it doesn't belong.

And one of those hands-free magnifiers, especially with an LED light, is useful as well.

You got stuff in there that's gotta come out. Keep at it.
 
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