G10/micarta pins… peening?

[Mimic Knife & Tool]

With various metal pins, I understand that the process of peening is what gives a good mechanical bond for the scales…. But what do you guys do for g10/micarta pins? Those can’t be peened right? Do you just rely on the epoxy?

Is there somehow a better chemical bond with epoxy between two resin based materials?

Thanks

 

[Crag the Brewer]

With various metal pins, I understand that the process of peening is what gives a good mechanical bond for the scales…. But what do you guys do for g10/micarta pins? Those can’t be peened right? Do you just rely on the epoxy?

Is there somehow a better chemical bond with epoxy between two resin based materials?

Thanks

Peening won't work, the material isn't mailable.

Some makers will cut grooves around the pins circumference, inside the handle. They feel those grooves make an epoxy bridge.

 

[C_Claycomb]

But what do you guys do for g10/micarta pins? Those can’t be peened right?

You can peen anything you like, as in, you can smack anything with a hammer....but not everything reacts well to it! Remember that when trying to make your cell phone work.
The best you can hope for with G10 pins is that you don't damage them too much. But you won't get a stronger join with your handle. As said, composites are not malleable ("of a metal or other material) able to be hammered or pressed into shape without breaking or cracking.") Don't believe me, get a brass pin and a G10 pin, lay them both flat and smack the side of them.

Is there somehow a better chemical bond with epoxy between two resin based materials?

G10 is epoxy based, so you are using epoxy to adhere to epoxy and handle material. You will absolutely get a stronger bond than with epoxy and metal.

There is another factor to think about. How thick are your scales? If you are sticking 1/8 thick wafer scales to a 3/32 thick tang, you will have more need of mechanical fastening of scales to tang. Thin tangs more likely to flex, putting peal load on your scale/tang bond line. AND short pins have little length with which to be bonded to scales. Use thick scales, greater than 1/4, and the length of holding bond line on your pin is such that you shouldn't need additional mechanical grip.

 

[Mimic Knife & Tool]

Peening won't work, the material isn't mailable.

Some makers will cut grooves around the pins circumference, inside the handle. They feel those grooves make an epoxy bridge.

You can peen anything you like, as in, you can smack anything with a hammer....but not everything reacts well to it! Remember that when trying to make your cell phone work.
The best you can hope for with G10 pins is that you don't damage them too much. But you won't get a stronger join with your handle. As said, composites are not malleable ("of a metal or other material) able to be hammered or pressed into shape without breaking or cracking.") Don't believe me, get a brass pin and a G10 pin, lay them both flat and smack the side of them.


G10 is epoxy based, so you are using epoxy to adhere to epoxy and handle material. You will absolutely get a stronger bond than with epoxy and metal.

There is another factor to think about. How thick are your scales? If you are sticking 1/8 thick wafer scales to a 3/32 thick tang, you will have more need of mechanical fastening of scales to tang. Thin tangs more likely to flex, putting peal load on your scale/tang bond line. AND short pins have little length with which to be bonded to scales. Use thick scales, greater than 1/4, and the length of holding bond line on your pin is such that you shouldn't need additional mechanical grip.

Thanks guys, my layman understanding of physics and chemistry figured along these lines. Cutting grooves might be an idea… and makes sense about thicknesses being crucial to the strength of the bond.

 

[weo]

Keep in mind that the primary purpose of pins for most makers nowadays is not to hold/pinch/adhere (this is what epoxies and glue is for) the scales to the spine, but to prevent shearing/sliding of the scales off the spine (which is not what epoxies or glue are good at).
When using malleable metals with some "plastic" (using the physics definition of plastic here) deformation properties, you can mushroom the head and this will be a mechanical way to pinch the scales to the spine, but not so with any sort of pinning that doesn't have any plastic deformation properties.

 

[Hengelo_77]

I always use a few blind pins as well.
As sayd before epoxy will stop scales lifting from the tang and form a water tight bond.
Pins will stop the sheering.
G10/CF/micarta pins are not weak but peened metal is stronger.
Many metal pins are just pins and not peened

 

[ea42]

Rough up the sides of your micarta pins with some coarse paper. If you have a rod rough up the whole rod before you cut, it's much easier. That'll expose and feather out the fibers which will catch the epoxy and make a much stronger bond.

Eric

 

[Mimic Knife & Tool]

I always use a few blind pins as well.
As sayd before epoxy will stop scales lifting from the tang and form a water tight bond.
Pins will stop the sheering.
G10/CF/micarta pins are not weak but peened metal is stronger.
Many metal pins are just pins and not peened

Can you tell me what you mean by blind pins?

Rough up the sides of your micarta pins with some course paper. If you have a rod rough up the whole rod before you cut, it's much easier. That'll expose and feather out the fibers which will catch the epoxy and make a much stronger bond.

Eric

That’s a good tip thanks

 

[Hengelo_77]

Can you tell me what you mean by blind pins?


That’s a good tip thanks

A few pins that don't go all the way trough the scales. (you don't see them on the finished knife)
I like using them so I can shape the scales before glue up, the scales will always line up that way.
Also it alows you to attach the scales and do the pins after the expoxy has set. That may be handy with domed pins or mosaic pins etc

 

[Alex Topfer]

you can smack anything with a hammer....but not everything reacts well to it

Can confirm, ask my neighbour

If you want that sort of mechanical lock you could do a tapered pin, using a tapered reamer for the hole. I think this would require the pins to be asymmetric, in that the placement on each scale would not be the same
Stainless seems like the easiest option if you're worried about corrosion

 

[Bill DeShivs]

Mechanical fasteners work. Peened pins, Corby bolts, screws, etc.
Why in the world would anyone want to use glue to hold a handle on? Eventually, the glue WILL fail on knives that have full tangs. Using G10 or mosaic pins will help keep the handles from shearing off, but real mechanical fasteners are much better.

 

[Mimic Knife & Tool]

Mechanical fasteners work. Peened pins, Corby bolts, screws, etc.
Why in the world would anyone want to use glue to hold a handle on? Eventually, the glue WILL fail on knives that have full tangs. Using G10 or mosaic pins will help keep the handles from shearing off, but real mechanical fasteners are much better.

This is the impression I’m under. However, I like the look of g10 pins so was wondering if there is some other way of mechanically fastening the scales

 

[Lorien]

you could counterbore the pin holes, use a nut and a bolt to fasten the scales on and then plug the hole with a piece of G10 pin

 

[Mimic Knife & Tool]

you could counterbore the pin holes, use a nut and a bolt to fasten the scales on and then plug the hole with a piece of G10 pin

Ding ding! That’s a winning idea there ima try that

 

[navman]

I would still like to see G10 corby bolts.....

 

[Mimic Knife & Tool]

I would still like to see G10 corby bolts.....

That would be great. I also thought of just threading my g10 pins and holes, cutting a slot in the end and screwing it in with some epoxy.

 

[Stacy E. Apelt - Bladesmith]

I think you guys are just trying to find a new way to do something that doesn't need a new way.
Simply gluing in the G-10 pins will be more than sufficient. Use a good grade epoxy and you will have to grind the scales off to remove them.

There are many tricks for making the scales even more secure:
Drill extra tang holes (Swiss Cheesing the tang).
Grinding a slight hollow in the tang and underside of the scales to create a glue reservoir.
Hidden pins.
Etc.

 

[Mimic Knife & Tool]

I think you guys are just trying to find a new way to do something that doesn't need a new way.
Simply gluing in the G-10 pins will be more than sufficient. Use a good grade epoxy and you will have to grind the scales off to remove them.

There are many tricks for making the scales even more secure:
Drill extra tang holes (Swiss Cheesing the tang).
Grinding a slight hollow in the tang and underside of the scales to create a glue reservoir.
Hidden pins.
Etc.

Yea, that may be. I like the ideas and options

 

[ScarFoot]

you could counterbore the pin holes, use a nut and a bolt to fasten the scales on and then plug the hole with a piece of G10 pin

I think the plug would look out of place since G10 has some grain to it if you were trying to match the handle. You could do essentially the same thing with a much smaller counterbored hole with a peened pin inside of it. You could peen it with a punch that way and use like an 1/8” pin and a 3/16” or 1/4” G10 plug. I still think that’s a lot of trouble but I’m firmly in the peened metal pins camp.

 

[navman]

Or....just rough up the g10 pin stock with some sandpaper and glue it up with quality epoxy. For pins and tubes that aren't to be peeled, I countersink a shallow bit on the INSIDE hole of the handle scales. Provides a glue reserve that won't get ground through.