How do you pin your scales to a mule?

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Bolster
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How do you pin your scales to a mule?

Postby Bolster » Mon Apr 05, 2021 10:55 am

When you pin your scales to a mule, how do you do it?

(1) Get pins the size of the holes in the mule tang, use them like alignment pins, slide the scales on, and rely on the epoxy to keep scales and pins in place. Any pin material will do, brass, stainless, whatever. Sand the ends flush as you finish the handle.

(2) Drill your scale holes with a very slight taper, widest to the outside, and use a brass or copper pin that's malleable. Then put on the scales and peen the pin so it widens into the slightly oversized hole. This method basically wedges the scales to the tang and does not rely exclusively on an epoxy bond. (I think this is the traditional olde-tyme slipjoint method.)

(3) Use rivets

(4) Don't use pins, use corby or sex bolts or screws (please give reason why this is better?)

(5) Other

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Re: How do you pin your scales to a mule?

Postby izzoyournizzo » Mon Apr 05, 2021 1:20 pm

I've been using Gulso Bolts on the 3d printed scales I've been making. This way I have the flexibility to remove them and change to scales/grips that would most appropriately match the application. I also think as the mules themselves have become a collectors item. Should you ever decide to sell you mule I think without scales added, the value might be increased. Last point is debatable :-)

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Re: How do you pin your scales to a mule?

Postby Joshcrutchley1 » Mon Apr 05, 2021 1:56 pm

Bolster wrote:
Mon Apr 05, 2021 10:55 am
When you pin your scales to a mule, how do you do it?

(1) Get pins the size of the holes in the mule tang, use them like alignment pins, slide the scales on, and rely on the epoxy to keep scales and pins in place. Any pin material will do, brass, stainless, whatever. Sand the ends flush as you finish the handle.

(2) Drill your scale holes with a very slight taper, widest to the outside, and use a brass or copper pin that's malleable. Then put on the scales and peen the pin so it widens into the slightly oversized hole. This method basically wedges the scales to the tang and does not rely exclusively on an epoxy bond. (I think this is the traditional olde-tyme slipjoint method.)

(3) Use rivets

(4) Don't use pins, use corby or sex bolts or screws (please give reason why this is better?)

(5) Other
I guess #1 is my go to. Just drilled to size and used epoxy but that was with a pin made from g10. I would like to try #4 and grind them down to look tike pins.

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Re: How do you pin your scales to a mule?

Postby RustyIron » Mon Apr 05, 2021 5:47 pm

Disclaimer:
I'm no knife maker, but I build a lot of cool stuff with high precision... unless it's sloppy with no precision. Here's some thoughts.
Bolster wrote:
Mon Apr 05, 2021 10:55 am

(1) Get pins the size of the holes in the mule tang, use them like alignment pins, slide the scales on, and rely on the epoxy to keep scales and pins in place. Any pin material will do, brass, stainless, whatever. Sand the ends flush as you finish the handle.
I don't like to rely solely on pins to hold the scales in place. I'm sure we've all run across old knives with loose scales. I want my knives to be fully functional fifty or more years from now. Wood scales exacerbate the problem. Wood can change shape over time. Modern epoxies can mitigate future problems.

The last one I did, the original intention was to use brass pins. I didn't have any on hand and didn't feel like turning down a larger brass rod, so I began hunting through the garage. I found some locating pins of the exact size needed. They're some kind of tool steel that was used for positioning parts on some flavor of Cold War fighter aircraft. Despite being as old as me, there wasn't a speck of rust on any of the pins, so they'll be great on this knife long after I'm gone. Use whatever material strikes your fancy.

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Re: How do you pin your scales to a mule?

Postby TomAiello » Mon Apr 05, 2021 7:14 pm

I use corby bolts. I've used several different methods (like just running a rod through and epoxying it).

Corby's are better because they actually screw the scales down tight and hold them while the glue sets, and they provide additional stability to the scale even after the epoxy has set. The lip inside is definitely worth the extra work. I actually did some destructive testing (breaking scales off a blank that I'd glued them to) and scales held on with corby+epoxy are _way_ more secure than scales held on with pin+epoxy. The pins basically just give front-to-back reinforcement , where the corby's give front-to-back and side-to-side reinforcement.

The corby also gives you maximum hold while the glue sets. You can do that with clamps, too, but the corby's are easier to work with because they are basically clamps that stay in while the epoxy sets.


I've never tried peening brass pins, but I'm interested in giving it a try just for the historical feel of it. I can't see how it could possibly be more secure than a corby, though. That's true for a brass corby, but doubly true if you are using a stainless corby.

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Xplorer
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Re: How do you pin your scales to a mule?

Postby Xplorer » Mon Apr 05, 2021 10:43 pm

Although I've done a few Mule handles using pins and epoxy, I much prefer using corbys and epoxy on most non-metal handle materials. For metal handle materials like copper, brass or nickel I prefer pins.

A few words about using corbys...

Corbys can present some accuracy challenges if you don't have the right drill bits, but once you have the correct bits (counter-bores actually) corbys are easy, clean and secure.

A corby provides the vertical support that a pin provides and also provides a mechanical clamping force to hold the scales against the tang so that there's no need to rely on epoxy to keep the scales from lifting off the tang. For anyone that is not familiar with what a corby looks like, the copper "bolts" in the picture below are corbys.
Image

Corbys can be used without epoxy entirely, or they can be used in addition to epoxy, in which case the epoxy is just there to seal the tang from water and air exposure. Epoxy can also help "lock" the corbys by sealing around them and their threads as well.
The special counter-bores that are made for corbys are very helpful. They leave a flat, square "shoulder" for the corby head to press on and they have a drill/guide built in to keep everything perfectly aligned over the guide/post hole. They are also made to fit corbys and are slightly "over" just enough to accommodate the swelling that occurs with many handle materials (such as G10 and micarta).
Here you can see the bit, the shoulder that the counter-bore leaves and the finished result.
Image
Image
Image
Image

Although I mostly use corbys myself, you could also use Loveless bolts in the same way. The Loveless bolts are not quite as clean looking because of the nut and thread size they use but they are stronger and have a very classic look and style.

Now a few words about using pins..

Pins can be used to clamp the scales against the tang as well, you just have to peen them.

This can be as simple as drilling a straight hole and hammering the ends of the pins until they flare a little (while being careful not to flare so much that you crack the handle material). Then you grind the pin ends smooth and don't remove more than you flared.

You can also "dome" the tops of the pins and leave them "proud" on the handle. Doming them is a great way to be able to use stag antler or elk antler scales without sanding the desirable texture smooth.

With some materials you'll want to use a tapered reamer on the ends of the hole and then peen the pin to fill the taper, with others a straight hole is best. With these methods pins will hold scales securely with or without epoxy just like corbys.

On this Mule I peened a titanium pin in the front and sanded it smooth. I used a corby in the rear of the handle.
Image
I don't actually suggest peening titanium pins..it's a P.I.T.A., just use nickel pins and make your life easier. If you choose to use pins I suggest soft metals like brass, copper or nickel.

Once you've made nice round holes (warning..normal spiral-flute drill bits do not make round holes, talk to me if you need help on this) and you have a perfectly fit pin, you should be able to peen them so tight that the fit will be flawless no matter what material you are putting them in.

But, the reason I prefer using pins in metal materials instead of non-metal materials in because metals are more malleable and therefor more forgiving when it comes to forcing the pins to conform to the shape of the hole.

Here's an example of nickel pins carefully fitted and peened into a nickel bolster with carefully drilled and reamed holes. Once finished the pins have no gaps and disappear. Then the main body of the same handle is attached with copper corbys.
Image
Image
Image
Image
Image
Image

Either method (pins or corbys) can be done well and result in a high quality and great looking knife handle.

I've only used "knife rivets" to attach a handle one time and I'll never do it again. They were weak and cheap IMO. I personally think knife rivets are not a high quality option so I won't use them.

If anyone has questions about any of the little details regarding using corbys or pins let me know and I'll gladly help out if I can.

CK
:spyder: Spyderco fan and collector since 1991. :spyder:
Father of 2, nature explorer, custom knife maker.
@Xplorer42 on Instagram.

Deadboxhero
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Re: How do you pin your scales to a mule?

Postby Deadboxhero » Mon Apr 05, 2021 11:06 pm

I never get tired of seeing your work Chad.

Perfection.
Xplorer wrote:
Mon Apr 05, 2021 10:43 pm
Although I've done a few Mule handles using pins and epoxy, I much prefer using corbys and epoxy on most non-metal handle materials. For metal handle materials like copper, brass or nickel I prefer pins.

A few words about using corbys...

Corbys can present some accuracy challenges if you don't have the right drill bits, but once you have the correct bits (counter-bores actually) corbys are easy, clean and secure.

A corby provides the vertical support that a pin provides and also provides a mechanical clamping force to hold the scales against the tang so that there's no need to rely on epoxy to keep the scales from lifting off the tang. For anyone that is not familiar with what a corby looks like, the copper "bolts" in the picture below are corbys.
Image

Corbys can be used without epoxy entirely, or they can be used in addition to epoxy, in which case the epoxy is just there to seal the tang from water and air exposure. Epoxy can also help "lock" the corbys by sealing around them and their threads as well.
The special counter-bores that are made for corbys are very helpful. They leave a flat, square "shoulder" for the corby head to press on and they have a drill/guide built in to keep everything perfectly aligned over the guide/post hole. They are also made to fit corbys and are slightly "over" just enough to accommodate the swelling that occurs with many handle materials (such as G10 and micarta).
Here you can see the bit, the shoulder that the counter-bore leaves and the finished result.
Image
Image
Image
Image

Although I mostly use corbys myself, you could also use Loveless bolts in the same way. The Loveless bolts are not quite as clean looking because of the nut and thread size they use but they are stronger and have a very classic look and style.

Now a few words about using pins..

Pins can be used to clamp the scales against the tang as well, you just have to peen them.

This can be as simple as drilling a straight hole and hammering the ends of the pins until they flare a little (while being careful not to flare so much that you crack the handle material). Then you grind the pin ends smooth and don't remove more than you flared.

You can also "dome" the tops of the pins and leave them "proud" on the handle. Doming them is a great way to be able to use stag antler or elk antler scales without sanding the desirable texture smooth.

With some materials you'll want to use a tapered reamer on the ends of the hole and then peen the pin to fill the taper, with others a straight hole is best. With these methods pins will hold scales securely with or without epoxy just like corbys.

On this Mule I peened a titanium pin in the front and sanded it smooth. I used a corby in the rear of the handle.
Image
I don't actually suggest peening titanium pins..it's a P.I.T.A., just use nickel pins and make your life easier. If you choose to use pins I suggest soft metals like brass, copper or nickel.

Once you've made nice round holes (warning..normal spiral-flute drill bits do not make round holes, talk to me if you need help on this) and you have a perfectly fit pin, you should be able to peen them so tight that the fit will be flawless no matter what material you are putting them in.

But, the reason I prefer using pins in metal materials instead of non-metal materials in because metals are more malleable and therefor more forgiving when it comes to forcing the pins to conform to the shape of the hole.

Here's an example of nickel pins carefully fitted and peened into a nickel bolster with carefully drilled and reamed holes. Once finished the pins have no gaps and disappear. Then the main body of the same handle is attached with copper corbys.
Image
Image
Image
Image
Image
Image

Either method (pins or corbys) can be done well and result in a high quality and great looking knife handle.

I've only used "knife rivets" to attach a handle one time and I'll never do it again. They were weak and cheap IMO. I personally think knife rivets are not a high quality option so I won't use them.

If anyone has questions about any of the little details regarding using corbys or pins let me know and I'll gladly help out if I can.

CK
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[url]https://www.youtube.com/user/shawnhouston[/ur]
Triple B Handmade Knives

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sal
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Re: How do you pin your scales to a mule?

Postby sal » Mon Apr 05, 2021 11:57 pm

Very nice Chad. Thanx for sharing.

sal

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Re: How do you pin your scales to a mule?

Postby Xplorer » Tue Apr 06, 2021 2:08 am

Deadboxhero wrote:
Mon Apr 05, 2021 11:06 pm
I never get tired of seeing your work Chad.

Perfection.
Thank you brother. I'm just hoping that if I post pics of these things more people will see how easy it is and give it a go. :)
sal wrote: Very nice Chad. Thanx for sharing.

sal
Thank you Sal. :D
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Re: How do you pin your scales to a mule?

Postby Skidoosh » Tue Apr 06, 2021 6:34 am

Beautiful work on here for sure! I use micarta or g10 rod/pins and epoxy the scales. It is straight forward and simple.

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Re: How do you pin your scales to a mule?

Postby Bolster » Tue Apr 06, 2021 8:52 am

Wow! Spyderbros, thanks so much! Will circle back and re-read, save-file, and respond, but wanted to insert a big thank-you here!

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Re: How do you pin your scales to a mule?

Postby Xplorer » Tue Apr 06, 2021 9:56 am

Skidoosh wrote:
Tue Apr 06, 2021 6:34 am
Beautiful work on here for sure! I use micarta or g10 rod/pins and epoxy the scales. It is straight forward and simple.
Using Micarta and G10 pins is a really good point that I forgot about, and I'm glad you mentioned it. :) :)
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Father of 2, nature explorer, custom knife maker.
@Xplorer42 on Instagram.

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Xplorer
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Re: How do you pin your scales to a mule?

Postby Xplorer » Tue Apr 06, 2021 9:59 am

When I wrote about pins I was talking only about metal pins and forgot about phenolic rods. For those that might be reading here for ideas or instructions for doing their own handle here's a few more things worth mentioning about these rods.

Carbon Fiber, G10 and Micarta rods are available in multiple diameters, and various colors, and can provide a great look. These are treated a bit differently in that they can't be peened or flared, but they are very easy to use and they bond with the epoxy far better than any metal pins do. They are also quite strong and provide more than enough vertical support. These rods are great for being creative with colors and materials because you can match and blend them into the handle or you can use them for high contrast.

In some cases you can also find lanyard tube in these materials as well. One word of caution about CF lanyard tubes...the "end grain" of a CF rod or tube is highly susceptible to fracture and splitting/splintering. If using a CF lanyard tube you need to thoroughly round and smooth the edges to a fine "fluted" looking finish in order to keep it from eventually chipping or splitting.
Here's a CF tube inside of a brass tube being rounded.
Image
The finished results.
Image
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@Xplorer42 on Instagram.

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Re: How do you pin your scales to a mule?

Postby TomAiello » Tue Apr 06, 2021 12:45 pm

I continue to be awe struck by your work. Amazing stuff.

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Re: How do you pin your scales to a mule?

Postby RustyIron » Tue Apr 06, 2021 1:45 pm

Xplorer wrote:
Mon Apr 05, 2021 10:43 pm
Although I've done a few Mule handles using pins and epoxy, I much prefer using corbys and epoxy on most non-metal handle materials. For metal handle materials like copper, brass or nickel I prefer pins.

That's some gorgeous work. Care to share how you create the scales out of the different materials, getting the boundaries really tight, and keeping everything symmetrical? I have no plans to make anything that extravagant, but it's good to have ideas for when projects arise.

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Re: How do you pin your scales to a mule?

Postby Xplorer » Tue Apr 06, 2021 7:38 pm

TomAiello wrote:
Tue Apr 06, 2021 12:45 pm
I continue to be awe struck by your work. Amazing stuff.
Thank you Tom. :) That's very nice of you.
RustyIron wrote: That's some gorgeous work. Care to share how you create the scales out of the different materials, getting the boundaries really tight, and keeping everything symmetrical? I have no plans to make anything that extravagant, but it's good to have ideas for when projects arise.
Thank you Rusty. :)

Short answer - very carefully ;)

Seriously though, there are steps that should be taken to keep things flat and corners square. I do my flat surface sanding on a 12x18 granite surfacing plate, and I use 1-2-3 blocks for keeping things square. Those are 2 inexpensive tools that anyone wanting to get flat edges to fit together perfectly flush should have.

Here's the surfacing plate for those who don't know what I was referring to. On top of it are a few pieces of aluminum in various shapes that I use for contouring and finish sanding.
Image

If you're unfamiliar with 1-2-3 blocks, they're a matched set of perfectly square blocks that are 1" x 2" x 3". For anyone that makes stuff, these are as useful as duct tape.
Here they're helping me keep my hand-work parallel.
Image
Here I'm using one as a drilling block under a part being reemed.
Image
Here I'm using it to make sure my table is square to my grinder belt.
Image

As for fitting curved pieces, that's more complicated but ultimately it really does come down to being careful. There are steps that I can suggest to help anyone wanting to do a curved bolster or something like that, but that's a rather advanced and specific discussion that I'll save for a time when someone is trying to do that type of junction and needs help.

The other advice for anyone assembling a multi-piece scale for the first time is to use SLOW CURE epoxy. Buy good epoxy from BSI or West Systems (or equal quality) and get the slowest they make. The slow cure epoxy gives you the best strength and water resistance, but most importantly it takes away the stress that comes with trying to assemble everything before the epoxy sets up.

If you any specific questions, just let me know. :)

CK
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Father of 2, nature explorer, custom knife maker.
@Xplorer42 on Instagram.

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Re: How do you pin your scales to a mule?

Postby RustyIron » Tue Apr 06, 2021 11:12 pm

Xplorer wrote:
Tue Apr 06, 2021 7:38 pm
There are steps that I can suggest to help anyone wanting to do a curved bolster or something like that, but that's a rather advanced and specific discussion that I'll save for a time when someone is trying to do that type of junction and needs help.
Thank you for the added pictures. And no, the detailed explanations are not necessary. When I'm next inspired to do some scales, I might go for some straight lines, but much simpler than your work. That's within my skillset. Thanks for the inspiration to up my game and try something new. I guess I'll have to buy the next Mule.

It's funny what you say about epoxies. I've always been intrigued by Japanese kintsugi, and this week I'm playing around with a project. Not having any ancient Japanese artisans to consult, I'm using whatever materials I have available. Fast set epoxy was the first step... and created a level of urgency. After that was some slow setting epoxy, which presents its own challenges. Challenges aside, the joy comes from creating new things and learning new skills.

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Re: How do you pin your scales to a mule?

Postby Xplorer » Wed Apr 07, 2021 12:22 am

RustyIron wrote:
Tue Apr 06, 2021 11:12 pm
... I guess I'll have to buy the next Mule. ...
Go for the MagnaCut! :D

When you're ready, get in touch with me and I'll help you plan your multi-piece handle build so you'll know what obstacles to expect and how to address them to make sure everything goes smoothly, if you'd like.

Best regards,
CK
:spyder: Spyderco fan and collector since 1991. :spyder:
Father of 2, nature explorer, custom knife maker.
@Xplorer42 on Instagram.

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Re: How do you pin your scales to a mule?

Postby Tucson Tom » Wed Apr 07, 2021 12:41 pm

This is just amazing. Thanks for taking the time and being patient sharing all of this!!

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Re: How do you pin your scales to a mule?

Postby RustyIron » Wed Apr 07, 2021 12:48 pm

Double post. Too many clicky-clicky without thinky-thinky.
Last edited by RustyIron on Wed Apr 07, 2021 12:59 pm, edited 1 time in total.


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