I've Successfully Lightened a Nailbreaker Backspring

[traumkommode]

This week, I received this Natural Canvas Micarta #85 Crownlifter, about which I was very excited. I really liked my dead skunk acrylic, and really wanted a micarta, and when I saw this one and that perfect butteryscotch gradient on these covers, I had to pay the secondary markup for it. I even sold a couple knives to make room in my budget for these 85s...

I was disappointed upon inspection of the knife. I like a firm pull, about a 7 is perfect for me. The dead skunk I had came with a perfect 7 main blade and maybe a 7.5 cap lifter. This knife, though, had an 8 main blade and a hitched solid 9 on the caplifter. I use my knives a lot, and was worried I wouldn't want to use this one, especially after overpaying for it and selling a couple other terrific knives just to buy it.

Anyway, I started digging up the old threads where I remembered people discussing pull weights. I never had luck with the "open halfway" method actually lightening a spring. But, there were other ideas...

(this is the knife post modification, as I didn't think about taking more pictures during the process.)

In this post, @sitflyer discusses using a file or sandpaper to take some off the tang. A challenging maneuver because the bladewell is so narrow. A challenge I was willing to take on. Upon inspection of my knife, it had a burr on the tang, so removing the burr helped the initial impossible "hitch" in opening.

In this post, @Phil Gibbs discusses rehafting the spring side of the handle to remove material from the springs, stating that this would lighten the pull. Inspecting my knife, I saw that the blades were not flush at open anyway, because the tops springs were higher than the tops of the blade tangs. @Bill DeShivs corroborated Phil's suggestion in this post, so I bellied up and busted out my 1x30" belt.

I also decided to add the small nail nick access notch with a Dremel wheel. It's not an EO like we're used to seeing on these 85s from GEC, but it is nice to better position the thumbnail to press upward into the nick rather than have to pull at a perpendicular. My caplifter was set pretty low in the handle, so this offers a lot more room.

In the end, the pulls on this knife are now pretty close to the pulls on my Dead Skunk 85, a solid 7 on the main and about a 7.5 on the caplifter. As I do not like the satin finish GEC puts on their bolsters and shields, I went ahead and polished these up on this knife. I achieved the same finish on the backsprings as GEC applies from the factory (which is better than trying to polish those things, IMO - the steel takes forever to get the grinder marks out of, and doing high polish always ends up leaving some visible lines that to my eye make the backside of the knife look incomplete.)

I'm sharing because this isn't the first time I've encountered a nailbreaker on a knife I wanted to love, but it is the first time that I had this much money into one and didn't want to sell it and look for another. I wanted to share the success because I've heard others talk about this difficulty with some of their knives, and my hunch is that there will be another member or two with the gumption to try this someday.

- Andrew

 

[huntnfishin]

Nice write up. This is good info...

 

[penguin9]

In this post, @Phil Gibbs discusses rehafting the spring side of the handle to remove material from the springs, stating that this would lighten the pull. Inspecting my knife, I saw that the blades were not flush at open anyway, because the tops springs were higher than the tops of the blade tangs. @Bill DeShivs corroborated Phil's suggestion in this post, so I bellied up and busted out my 1x30" belt.

I'd like to try this on one of my (much cheaper) knives, but have a couple of questions:

How much do you think you sanded off of the backsprings?

Also, did you sand the entire length of the knife or just back to the center pin? I'm guessing that going only to the pin would achieve what you wanted, but going the entire length would keep the profile the same and would look better.

I like the look of that micarta too, BTW.

 

[Cutfinger]

Nice work, traukommode!

I thinned the spring on a nail breaker secondary, by filing the back spring, with the blade half opened. It has a cam tang, so the spring protrudes a lot with the blade in that position. The spring is now sunk a bit in opened or closed positions, but the pull is tamed. Also, main blade pull was ideal, do I didn't try what you did.

 

[Ernie1980]

Nice job! I have done some work on my knives, but not to that level! That took some guts but it turned out awesome

 

[sf fanatic]

Nice job indeed! I wish I had known this a few years ago when I had a Whaler that was a nail breaker and then some. Ended up selling it.

 

[JTB_5]

Nice work, Andrew! I’m assuming you just sanded down the whole back spring in the 1x30 with the knife closed? I’ve done that on some 71s just to get the right finish. What method did you use to polish the bolsters and shield?

 

[Will Power]

Grand skill and thanks for compiling those references .

Admire that cut-out, it's what a lot of secondaries need and doesn't detract from the appearance of the knife either (EO-notches tend to....)

 

[glennbad]

Great work making that knife "your own".

 

[Obsessed with Edges]

I'm always impressed to hear of such elegant, well thought out solutions to what would be a perplexing problem for a lot of us, not knowing what approach to take. And the finished product looks as if there never was an improvised 'fix' in the first place. Looks as pristine as a new factory knife should.

Nice work.

 

[Planterz]

I did kinda the same with my 74 ebony (2019?). By very slightly rounding the corner where it initially tensions the spring upon opening I was able to slightly lessen and greatly smooth out the opening pull while retaining all the snap. I also ever-so-slightly (and I mean just the tiniest little bit) did the same with the other corner of the tang, simply to smooth it out a bit. I doubt I did anything more than years of "break-in" would have eventually done. I used a very narrow, flat diamond file that came with the Microtech Scarab I once owned. I used the same file to flatten the round cam tang on my Case slimline trapper to give it a half stop.

 

[traumkommode]

I'd like to try this on one of my (much cheaper) knives, but have a couple of questions:

How much do you think you sanded off of the backsprings?

Also, did you sand the entire length of the knife or just back to the center pin? I'm guessing that going only to the pin would achieve what you wanted, but going the entire length would keep the profile the same and would look better.

I like the look of that micarta too, BTW.

I would say I removed .010"-.020" but I can't be sure how much within that latitude. The springs weren't proud at open, they were simply thicker/taller than the blade tangs in the end of the bolsters.

I did most of the length of the springs. The material before the center pin doesn't really matter, BUT the profile of the handle would change in a noticable way, I think. It did ever so slightly on this knife, I think you'd just have to look really close and hard to see it. It's also due to the teardrop shape - the only need to sand down say the butt end of the knife is to blend the surface so it looks uniform. On a knife like a 15 or 77 or 78, you'd be sanding the whole thing. I guess the takeaway is that I would let the handle shape dictate that decision, as a knife like a 33 or a 92 quickly becomes a different animal...

Nice work, traukommode!

I thinned the spring on a nail breaker secondary, by filing the back spring, with the blade half opened. It has a cam tang, so the spring protrudes a lot with the blade in that position. The spring is now sunk a bit in opened or closed positions, but the pull is tamed. Also, main blade pull was ideal, do I didn't try what you did.

That's a good idea, too! I had an old case barlow with a pen blade that you couldn't open without a tool. That knife would have been ideal for this kind of sanding. I don't mind a sunken spring on a knife like that, and wouldn't want to alter the main as it was perfect like yours.

 

[traumkommode]

Nice job! I have done some work on my knives, but not to that level! That took some guts but it turned out awesome

Thanks Ernie! I haven't modded anything in a while, and while it definitely wasn't a first go at hafting (I think my most extensive hafting undertaking was a Bark River handle reprofile, I'll have to look for that from about 8 or 9 months ago), I was a little nervous to do it. One of those where I had to just jump in and not think

Nice job indeed! I wish I had known this a few years ago when I had a Whaler that was a nail breaker and then some. Ended up selling it.

I had heard those Whalers had hard pulls. Was it both blades or just one that was difficult?

Nice work, Andrew! I’m assuming you just sanded down the whole back spring in the 1x30 with the knife closed? I’ve done that on some 71s just to get the right finish. What method did you use to polish the bolsters and shield?

Thanks Josh! Yeah, I got most of the whole back on the belt, blending down near the swell where I didn't remove any material but where you could see the "cut-in" line, as it were. It's a well-worn 120grit belt, I believe, is that what you use for the finish on your mods?

 

[traumkommode]

Grand skill and thanks for compiling those references .

Admire that cut-out, it's what a lot of secondaries need and doesn't detract from the appearance of the knife either (EO-notches tend to....)

Thanks, Will! Nice to see you (and with a Gold Membership!). Yes, it seems like those cutouts are more frequently found on older knives. I think a couple GECs have seen them, but not many that I recall. I have a 5-Dot Case Jack on the way that has that cutout for the secondary, and that's what inspired me to do it. I need to pay attention, I wonder if secondaries used to simply be set lower than GEC typically does.

Great work making that knife "your own".

Thanks Glenn! That's nice praise coming from you.

I'm always impressed to hear of such elegant, well thought out solutions to what would be a perplexing problem for a lot of us, not knowing what approach to take. And the finished product looks as if there never was an improvised 'fix' in the first place. Looks as pristine as a new factory knife should.

Nice work.

Thank you! I'm very happy with how it turned out. I also hadn't recalled those threads where the suggestion was to re-haft, so keeping them linked to a more recent thread seemed like a prudent choice.

I did kinda the same with my 74 ebony (2019?). By very slightly rounding the corner where it initially tensions the spring upon opening I was able to slightly lessen and greatly smooth out the opening pull while retaining all the snap. I also ever-so-slightly (and I mean just the tiniest little bit) did the same with the other corner of the tang, simply to smooth it out a bit. I doubt I did anything more than years of "break-in" would have eventually done. I used a very narrow, flat diamond file that came with the Microtech Scarab I once owned. I used the same file to flatten the round cam tang on my Case slimline trapper to give it a half stop.

How did you access the first opening tang? Was it with the blade open, filing in the blade well? That was the only way I could imagine doing this feasibly. I remember those 74s had a wide range of pull weights, from 6 all the way up to 8 or 9. That's always interesting to see from the factory.

 

[sf fanatic]

Thanks Ernie! I haven't modded anything in a while, and while it definitely wasn't a first go at hafting (I think my most extensive hafting undertaking was a Bark River handle reprofile, I'll have to look for that from about 8 or 9 months ago), I was a little nervous to do it. One of those where I had to just jump in and not think



I had heard those Whalers had hard pulls. Was it both blades or just one that was difficult?


Thanks Josh! Yeah, I got most of the whole back on the belt, blending down near the swell where I didn't remove any material but where you could see the "cut-in" line, as it were. It's a well-worn 120grit belt, I believe, is that what you use for the finish on your mods?

The main blade was a 8-9 and the secondary was definitely a nail breaker which to me pretty much made it unusable.

 

[traumkommode]

The main blade was a 8-9 and the secondary was definitely a nail breaker which to me pretty much made it unusable.

I kinda want to get ahold of a single spring pen knife and try it out now.

Oh, and JTB_5 - to polish the bolsters, I usually just hand sand from 600 grit up to 2000, and then smear them with Flitz and buff with a Dremel wheel until shiny. I've also used the buffing attachments for a drill with rouge, and that can turn out a little nicer, but I think I'm out of those. Working with limited tools :/

 

[JTB_5]

Thanks Ernie! I haven't modded anything in a while, and while it definitely wasn't a first go at hafting (I think my most extensive hafting undertaking was a Bark River handle reprofile, I'll have to look for that from about 8 or 9 months ago), I was a little nervous to do it. One of those where I had to just jump in and not think



I had heard those Whalers had hard pulls. Was it both blades or just one that was difficult?


Thanks Josh! Yeah, I got most of the whole back on the belt, blending down near the swell where I didn't remove any material but where you could see the "cut-in" line, as it were. It's a well-worn 120grit belt, I believe, is that what you use for the finish on your mods?

I started out with a 120 and a 240, but have since gotten a 320 and a 400, which I will use to finish. If I want more than that I break out the 600 and 800 paper and hand sand. The sander I have doesn't have the variable speed, so I have to be more careful at the lower grits (especially if it is a new belt) not to take off too much material. It has been awhile since I've done anything though, as even the cheaper 71s (including users) are marked up.

 

[traumkommode]

I started out with a 120 and a 240, but have since gotten a 320 and a 400, which I will use to finish. If I want more than that I break out the 600 and 800 paper and hand sand. The sander I have doesn't have the variable speed, so I have to be more careful at the lower grits (especially if it is a new belt) not to take off too much material. It has been awhile since I've done anything though, as even the cheaper 71s (including users) are marked up.

I see. I could probably use some 800 and 1200. After the belt, I hand finished at 220, 400, and then a quick kiss of 2000 - not too much with the last one, just a little. The non-variable speed 1x30" belt that I have is way too quick for me to want to do more than shape and rough finish with it.

 

[Planterz]

How did you access the first opening tang? Was it with the blade open, filing in the blade well? That was the only way I could imagine doing this feasibly.

Exactly. I forgot to add that I also dabbed a bit of Simichrome in there and worked the action a whole bunch of times (probably a few hundred) for good measure. For this knife I was more interested in smoothing out the action than making the pull weaker, but it had the effect of improving both. It was rough when I got it, like, as yours seemed to be, that the surfaces were unfinished and perhaps even galling. I'm not even sure I could assign a "pull number" to it, because the action was so rough and inconsistent, sometimes getting "stuck" at random angles. 7-8 depending on if it got stuck or not. Now the pull is still nice and strong, I'd say about 6.5, and if anything snap has improved because it's smooth rather than rough and dragging.

 

[JTB_5]

I see. I could probably use some 800 and 1200. After the belt, I hand finished at 220, 400, and then a quick kiss of 2000 - not too much with the last one, just a little. The non-variable speed 1x30" belt that I have is way too quick for me to want to do more than shape and rough finish with it.

You must still be using the same Harbor Freight you told me about, eh? I have that one you recommended and it definitely takes a light touch if you don't want it to get away from you! I've made some bone-headed mistakes before by not being careful enough. Jason Ritchie had a sander he was going to sell me when he was done with it, but I guess he is still using it. I don't have the time to make much use of it even if I did want to spend the money and try reselling to recuperate the costs.