Scales Pins question

[Alarion]

Ok, actually 5 questions:

1) I've read in a recent thread about how the pins of the scales should be peened (not pounded) Which is the difference?

2) Wouldn't such a procedure fracture the scales due to the pressure exerted by the expanding pins?

3) Moreover, some knives have concealed pins, which are completely inside the scales. How can one peen such pins?

4) In the same thread I read the statement "it's not epoxy that keeps the scales in place: it's pins.
Are pins epoxied in place?

5) What does it mean that the pin holes must be countersunk (tapered)?

 

[sattley]

First, the easy answer to all the questions. Just epoxy the scales on and epoxy the pins in the scales. They will never come off without a hammer and wedge.
If you insist on peening, then...
1. Peen very lightly, (light hammer, light blows) just enough to swell the pin, not enough to crack the scale (good luck). Pounding is what I do to bolsters (dont want the pins winking at me when I polish them).
2. see # 1
3. Dont know. Never done one.
4. Its both, epoxy and pins together
5. Counter sinking is slightly tapering the hole in the scales then filling the taper by peening.

Of course this is just my opinion. After having to break a few scales off that were held only with epoxy and pins and never having a failure or evening knowing of someone who has, it would be hard to convince me that peening scales is necessary.

 

[Kumdo]

I agree with everything sattley said. As for question #3, you can't peen hidden pins, but you won't need to. Just make sure the pins go deep enough into the scales and use a good epoxy. Plenty strong enough.

 

[Alarion]

About what I thought of the whole thing, but since I'm making my first knife, and don't want to end up with a useles POS, I prefer to ask the experts before screwing up everything due to a badly made ass-umption

 

[Kalindras]

On the couple of hidden pin handles I've done, I used small-diameter brass all-thread rod for the pins (I've also done this on a couple of normal ones, too, but the threading makes its shape unpredictable as you grind it away...). This gives the epoxy something to really bite into, and I've never had any problems with the scales loosening up, even though one of the pieces has been used (against my warnings to the contrary) as a throwing knife at several Ren Faires by its owner.

On normal pin stock, I'll usually put several grooves along the length to create the same type of interlock for the epoxy. Every little bit helps!!

 

[Alarion]

Oh! Sure, I didn't think about it! Thanks!
Another question...
How can I taper the pin holes?

 

[Jerry Hossom]

Surface preparation is the most important aspect of handle attachment in my experience. If epoxy has a clean and tectured surface to hold onto it will not let go. The only epoxy failures I have ever seen were where the epoxy released from a surface because the surface was contaminated or polished or the epoxy was badly overheated. I generally etch all my tangs to make sure they are clean and have a good rough surface for the epoxy to hold onto, and I just clean all my pins with a little medium grit paper to make sure they are clean and have a toothy surface as well.

I have never had a pin let loose, but it may be possible if the fit is too tight. I use a size F drill for 1/4" pins and a #30 drill for 1/8" pins. These allow about 0.003" for the epoxy. If it's too tight, the epoxy will be squeegeed off the pin as it's inserted. No epoxy, no hold. Even on ivory that small gap is not visible.