Help, my pins are showing (how embarassing...)

Jason Wernli

Jason Wernli

Well-Known Member
So I finished my 5th knife and am a little frustrated because I can barely see the pins on the bolster...just one side.
I have not had this issue on my other knives.
I am not exactly sure the nature of my error.
1/8" Boslter and pins are 416 stainless. I cut a small chamfer after I drilled the holes to allow the pin to mushroom.

Any help would be much appreciated!!!

- J

Bolster.jpg
 
I like to put a ever so slight countersink on the bolsters and then hammer the heads of pins into the counter sunk holes till they are filled. Then grind or file smooth, they disappear.
 
Yah, that is pretty much what I did... but I used a tapered reamer instead of a countersink. Was that a mistake?
or did I not peen them correctly?
 
Jason, I like to take my time peening the heads , I start on the outer edge first and work my way to the center so as to get a tight fit on the circumference of the pin. That done I give her a few good smash to finish it off.
 
It just looks like you didn't fill the "chamfer".
Maybe you're chamfering too much or you didn't have enough pin to fill the hole. I do a lot of bolsters and the best tool I've found to date is a round pointed diamond file. A couple of firm push and twists does the trick better than any of my reamers. Also, when you think you've peened enough......whack it like a red headed step child for good measure, fairly hard.

Rudy
 
Fred and Rudy,
Thanks, sounds about right. I will watch my taper carefully and peen more thoroughly...
How deep do you take the chamfer? I am worried that after I peen, the grind and shape the bolster that I will grind past the chamfer while shaping.
The more I think about it, I guess the depth vs the cut angle is critical. I like the idea of using a hand file instead of trying to line it up on my drill press. I may use Dykem to get a better witness next time.

Rudy, I am a red headed step child, so this should come naturally!!!! Hehehe...

Thanks guys,
- J
 
Jason Wernli said:
Rudy, I am a red headed step child, so this should come naturally!!!! Hehehe...

Thanks guys,
- J
Click to expand...

No offense intended to anyone who may be one, maybe I should of used the mother in law reference.

After a couple you'll get the feel for it. I use 3/32 pins mostly and the file I use will give me at least a 50% bite down the hole. The file for 1/8" pins gives me about 1/3 bite in the hole. I rarely do more than 2 firm push and twists, haven't lost one yet. I should mention that I have multiple needle file sets in different shaft sizes, don't depend on just one to do every job. If you see lots of material falling out the hole, you've probably gone too far. Cut your pins a hair longer than the hole is wide and give it a gentle dome on the end, drive from the center out. This drives material down the shaft of the pin making it bulge in the hole, then do what ever you normally do.

Rudy
 
I still fight this but I've had better luck lately.

A couple things to try

  • I'm guessing you matched the stainless, ie 416 bolster, 416 pins
  • use 3/32" pins instead of bigger. smaller pins, smaller hole to fill in
  • sand the oxidation off the pins to a bright finish
  • clean out any glue, bluing fluid, cutting oil from the hole, it should be bright finish clean
  • use a small tapered pin reamer to give the hole a conical shape. i think for a 3/32" you want a 0/2 (or is it 2/0?) tapered pin reamer (look for one that has around a .093" thickness)
  • tap, tap, tap around the top edge of the pin (not straight down on the pin), to mushroom the pin head, flipping often, tap, tap, tap until the hole is really filled in
  • now it's time to smash, smash, smash straight down to mush the pin metal into the bolster metal. You want to blend the pin metal into the bolster metal. Smear it in.
t
 
Last edited:
BossDog said:
I still fight this but I've had better luck lately.

A couple things to try

  • I'm guessing you matched the stainless, ie 416 bolster, 416 pins
  • use 3/32" pins instead of bigger. smaller pins, smaller hole to fill in
  • sand the oxidation off the pins to a bright finish
  • clean out any glue, bluing fluid, cutting oil from the hole, it should be bright finish clean
  • use a small tapered pin reamer to give the hole a conical shape. i think for a 3/32" you want a 0/2 (or is it 2/0?) tapered pin reamer (look for one that has around a .093" thickness)
  • tap, tap, tap around the top edge of the pin (not straight down on the pin), to mushroom the pin head, flipping often, tap, tap, tap until the hole is really filled in
  • now it's time to smash, smash, smash straight down to mush the pin metal into the bolster metal. You want to blend the pin metal into the bolster metal. Smear it in.
t
Click to expand...

Good explaination Boss.
 
I found that on bolster pins using the flat of the hammer worked best for me. The rounded end wants to roll the head of the pin over, while the flat pushed the pin material into any space that was there. I never did taper bolster holes doing it this way, so it eliminated having to fill a larger hole. Frank
 
This all makes good sense to me. I appreciate the detailed explanations.
Next time one of you is attaching a bolster, I would love to see close up pictures of:
1) Pins in the bolster before peening and 2) After peening...

I have been leaving about .075 to .100 stick out on the pins before peening.
- J
 
my experience has been to leave about the 1x to 1.5x the diameter of the pin above the surface of the bolster. This depends on how big of conical hole you use in the bolster of course.
Much more than that and the pin tends to fold over when peening and leave voids (in the conical hole), much less than that and you end up grinding away a lot of material to make it all flush.
 
Jason , one thing that helps me is to drill a small shallow hole in the flat part of my vise. I drill it about 1/8 to 5/32 deep and what ever size the pin materials you will be using. When i put the pins in the bolster, and lay it flat ready to peen, i locate the pin in the hole , this allows for enough pin stock to stick out the back side. You wont have to fight with the pin trying to move back and forth in the bolster until you get it peened on both sides. It also allows for the bolsters to lay flat against the vise or anvil, and flat against the knife. When you flip the knife over , you will have enough pin to peen. I start it down easy and after its seated down , i smash it like the other folks do, gotta have enough pin to fill the hole, and smash it enough to fill the hole. You gotta hit it hard enough to make the pin materials flow into the hole. Your pin holes will go away. This works for me very well.Scott
 
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