Blade Rap: How to recognize?

Stixmagill

Stixmagill

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I have collected quite a few knives over the last short while. I would like to know how to recognize blade wrap so that I can potentially resolve it, and the knives that may be problematic. I did look to see if I could find a thread on this topic, did not find it. Steer me towards it if it’s out there please. Thanks you guys, great forum, great resource.
Sincerely,
Scott
 
Blade rap is when the edge hits against the spring when the blade is closed. This causes edge deformation, usually in the form of rolling but sometimes pure flattening or occasionally even chipping.

Search "pocketknife blade rap".
 
Yes, if it's happening, there'll always be a tell-tale flat spot (or chip) somewhere along the edge. Under bright light, turn the edge UP to face the light and look for a reflection along the edge. Or run the edge of your fingernail/thumbnail along the edge and feel for the divot. If you find a divot and then sharpen it out, then close the blade and notice it's flattened again, you've verified what's going on.

Sometimes, you might also see a mark or dent on the inside face of the backspring where the edge is rapping against it.

Some really bad examples might actually leave the blade edge resting against the backspring when closed. In handling the knife with the blade closed, you might feel a grinding sensation via the spine of the blade, as the edge scrapes laterally against the backspring. That's like fingernails on a blackboard to me - always makes me cringe to find that issue in a knife.

Edited to add:
And more often than not, the point of contact will usually be in either of two places: (1) at the swell in the backspring where the center pin is located (the spring's anchor), or (2) in an area near the tip of the blade, where the rear end of the backspring curves up into the butt end of the handle. I think more of the blade rap issues I've seen are usually near the tip, or in the upsweeping 'belly' of the edge just before the tip.
 
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2 fixes:
1) Sharpening it out enough times. The blade will eventually no longer hit the spring.

2) Install a THIN piece of leather in the blade well on top of the spring, covering where it is coming into contact.
("Thick" might raise the tip proud.)

A potentally simpler option if the blade is not resting on the spring (a French Lagoule, or other kniife without a kick for example), is lower the blade manually when closing.
No snap = No Rap.
 
One other potential fix, if a blade has a kick on it:

Some have 'stretched' or peened the kick at the rear of the blade, to effectively lengthen it so it comes to rest against the backspring slightly earlier in the closing arc, leaving the edge further distanced from contact with the backspring. I found one old thread from 2004, with a posted reply including a description of how that might be done (in post #11), linked below:

 
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Here is an example, I have this RR doctors knife, you can see the bright spot with the edge rolled neqr the center of the blade, right where the high spot on the spring is around the center pin. I have had this issue on several RR knives
20231031_193850.jpg20231031_193920.jpg
 
chevyrulez1 said:
Here is an example, I have this RR doctors knife, you can see the bright spot with the edge rolled neqr the center of the blade, right where the high spot on the spring is around the center pin. I have had this issue on several RR knives
View attachment 2375246View attachment 2375247
Click to expand...
Ok, I can easily see what’s going on now. Thank you for the great pic.
Thanks to everyone who helped explain the details.
Basically, if I can’t find damage to the blade, then I don’t need to be worrying about it. If I do find damage to a blade, then I will investigate this as possible cause. Also I learned to be careful closing some knives for this reason.
The forum is so helpful. Thank you all.
Sincerely,
Scott
 
Here is an example of blade rap on a custom slip-joint of mine. A sharp edge is too narrow to reflect light. But here, where the blade rap occurred, it has flattened the edge and made it quite shiny. This is on the belly of the blade out near the tip.

1698805440140.png
 
chevyrulez1 said:
. I have had this issue on several RR knives
Click to expand...
I've been "lucky". Haven't had had to put up with RAP* on any of my 60+ RR's.
I wonder if RAP is pattern dependemt?
I've not experienced it on a Barlow, Canoe, Teardrop, Stockman, "Sodbuster" (type), 2 slipjoint folding hunter, .or other pattern I have from different mnufacturers.

*IMHO "Blade Rap" sucks. However, it is preferable to "RAP Music".
RAP "Music" gives me a headache. If I want to be cursed at, called nasty names, blamed for and accused of things I ain't never done did in my "life" (and have less than zero desire to do), and otherwise be disrespected, I can just call my ex wife, thank you very much. 🙄
I just cannot relate to that "music".
(or "Country Western" "music". All that "singing" through their nose, along with the fake "southern" accent and/or "Texas" drawl ... gives me a headache AND a earache.🙄 Rock n Roll can roll on down the mountain (or off a mile high cliff) s'far as I'm concerned, too.)
 
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I have a Carl Schleiper Stag Sod Buster, which when you look inside the handle at the spring, there is a "Bump" on the spring, close to the pivot pin. When you close the blade the tang of the blade hits that "Bump" which keeps the edge of the blade from hitting the spring. Once closed you can push down on the blade and it moves about a 1/16 of an inch, just enough so when closing the knife the edge is clear of the spring. Why other companies do not do the same thing is beyond me. John
 
John A. Larsen said:
I have a Carl Schleiper Stag Sod Buster, which when you look inside the handle at the spring, there is a "Bump" on the spring, close to the pivot pin. When you close the blade the tang of the blade hits that "Bump" which keeps the edge of the blade from hitting the spring. Once closed you can push down on the blade and it moves about a 1/16 of an inch, just enough so when closing the knife the edge is clear of the spring. Why other companies do not do the same thing is beyond me. John
Click to expand...
It's that famous German engineering we hear about on the old VW commercials. ☺️ 🍻
 
John A. Larsen said:
I have a Carl Schleiper Stag Sod Buster, which when you look inside the handle at the spring, there is a "Bump" on the spring, close to the pivot pin. When you close the blade the tang of the blade hits that "Bump" which keeps the edge of the blade from hitting the spring. Once closed you can push down on the blade and it moves about a 1/16 of an inch, just enough so when closing the knife the edge is clear of the spring. Why other companies do not do the same thing is beyond me. John
Click to expand...
Some of A.G. Russell's designs had a stop pin through the inside of the handle, opposite where the kick on most blades would be and just above the inside face of the backspring. A.G.'s 'Cowboy' and 'Rancher' patterns (sodbuster-like, BTW) have that feature. So, the blade tang comes to rest against the stop pin, instead of resting against the inside of the spring itself. That makes it impossible for the blade to overtravel against the outwardly-deflecting spring with a hard closing snap, which is how blade rap happens much of the time.

Some of Camillus' patterns featured the same stop pin in the handle - I have a double-lockback large trapper pattern, branded by Moore Maker and produced by Camillus, with that feature (pics below). I think the common factor between all was Phil Gibbs, who worked for Camillus and whose name is on the Camillus patent for their double-lockback design, and whom was later hired by A.G. Russell as a design engineer after Camillus shut down. ;)
axGwC0Z.jpg

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