Bolster Peening?

S

scherar

Well-Known Member
Any advice on how to eliminate ballooning/deforming the fronts and backs of my bolsters while peening them? I have also tried using my pin press but it seems to do it just as badly. Right where the pins are, the press makes the pin pooch out the front & back of the bolster material. I am using 416 ss and my bolsters are typically 1/2" in width. The deforming of the the front is a cosmetic blemish, and the deforming of the back messes up the fit of the handle material to the back of the bolster.

Additionally, I use 1/8" pin stock for my bolsters. I have read where many people are going to 3/32" stock for their bolsters. Will using the smaller diameter material help out with this? I have also read where people say to beat the heck out of it with a small sledge. No one else runs into this problem when getting aggressive with peening?

Thanks for any help.

www.scherarknives.com
 
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I don't see any reason to wail on your bolsters like that. I pretty much use the same technique as when I'm pinning my scales. Several light, but deliberate taps will tighten things up very nicely. I use 1/8" pin stock almost exclusively and use an 8 oz. ball-pein hammer for everything. I start with the ball and tap the center of the pin to expand it outward, then use the hammer face to set everything tight. Try choking up on the hammer if you need a little more control. What are you using for an anvil?
 
I may well be one of the bunch that is getting a little "Western" with my pin installation, but this is how I do it. I use 304 stainless bolsters and 3/16" 304 pin stock, 220 grit wet-or dry scuff on the pins and I taper the holes with a reamer. I use a 3 LB generic squarish machinist's hammer that I've rounded the face very slightly on. With the pins standing 3/16" proud of the bolsters on each side, I smash them on the anvil until the heads are about 5/16" flat and starting to blend in with the bolster stock. I shoot for about 5/16" minimum between the edge of a pin hole and either my dovetail on the bolsters or the mirrored front face. Any closer and I get that "bulge", I've found. Every so often I end up filing a slightly bulged dovetail flat again with a triangular file.
My bolsters are pretty good sized...I suppose with yours being 1/2" wide there isn't a lot of room for the steel to go. Are you using a tapered reamer on the holes to allow a little room for expansion? This can introduce a little wiggle in the fit up that I resolve with a small needle nose vise-grip hold everything in correct alignment until it's tightened up after a couple of lighter taps.
 
Thanks for the input. I am using a small piece of railroad rail (the narrow gauge stuff) for an anvil. I welded a small piece of 1095 on one end that has demples (partial holes drilled) to start my peening, which allows the under side to swell when starting on the top side. After a couple times back and forth, then I go directly onto the rail. A solid anvil would probably make a difference. Probably much less 'bounce'.

I do not use a reamer right now, though I thought I would try one out the next time I place an order.

Maybe I am getting too aggressive with the pins. I just try and do everything I can so they don't show in the end.

Thanks again.

www.scherarknives.com
 
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For getting the pins to be "invisible", one thing I heard from a maker (I think it was Todd Davison, but don't hold me to that), was to let everything sit for a good half hour after peining before cleaning up the bolsters/pins. I don't know if there's any magic to this, but I figured it couldn't hurt. I do use a tapered reamer also. I give it maybe one or two full twists just to give a little room for expansion. I try to have the bolsters about 95% to shape before attachment so I'm not removing material below the expanded part of the pin as I'm finishing the handlle. Also, you don't want to ream all the way down the hole, or you will not have precise alignment.
 
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This is Stuart Mitchell at work.

[video=youtube;qlGclWK-99w]http://www.youtube.com/watch?feature=player_embedded&v=qlGclWK-99w[/video]

He uses straight holes and straight pins.
 
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