integrated bolsters

[Kirby Bletcher]

My question is for those of you that make folders with integrated bolsters and liners. When using 416ss do you heat treat before machining or not at all? Also what is the best way to hold it (vice, magnetic chuck, special jig)? I'm a little worried about the material warping is this an issue?

Thanks for the help!

[David Broadwell]

Kirby,

In my early days as a folder maker, 93 and 94, I made a couple of interframe and several integral bolster/liner folders. I never had any problems when I used mild carbon steel (for gun bluing) but 416 was a bit of a pain. When you mill it you relieve some stresses and it can warp, which it did on me. After the mill work I had to straighten things back up. I've used 416 in both heat treated state and annealed. If you don't HT 416 it can oxidize, and it's not pretty! I clamped handles in a vise and rotated it as necessary to set angles at the backs of bolsters, then setting it up the opposite way for the second handle. I have also made a jig with pins, put it in the vise, and clamped the side plate to it. A magnetic chuck is fine when surface grinding, but milling puts a lot of pressure on the part when cutting and I doubt it would hold securely.

A later phase involved soldering damascus or mild steel bolsters to mild steel liners, then bluing them. As much as I hate soldering, I found this much less stressful. Can you solder or weld your 416 bolsters to 410 liner stock?

David

[Don Robinson]

I make integral folders pretty often using 416 SS. Yep, it always warps as David says from relieved internal stresses. You have to straighten it. How? I straighten it by hand. Roll it over the edge of your bench holding the ends with both hands and check with a straight edge.

However, for me I don't like soldering. I'd rather mill the 416 and fit scales.

[Kirby Bletcher]

Thanks for the reply guys! I knew I could count on you guys for good info. I thought I would be dealing with some warping issues. Ill be give it a try we'll see how I make out.

As far as soldering I have been practicing with little success. I use stay clean flux with silver solder. I coat ('tin') the surface of the liner with solder than clamp the bolster on with a spring clamp. Then heat it up until the solder melts. After it cools I'm able to grind and drill the material without any problem but a few taps with the hammer and it will fall off. May be I'm expecting to much but it seems a bit weak. Should I be tinning both surfaces? Any additional help is much appreciated.

Thanks

[Don Robinson]

Tinning is usually required on only one of the surfaces.

Since the tinning is on the liner, you should apply all the heat to the bolster and let the heat draw the solder to the bolster.

Sounds like your bolster didn't get hot enough to draw the solder. Solder follows heat.

Don't give up. You'll be able to make it work. What kind of torch are you using?

You're doing the right thing here by asking.

Remember the old saying,

'If at first you don't succeed, ask someone who knows.' That's modified a bit, but it's what I do.

[Kirby Bletcher]

Don, I'm using a Bernzomatic propane torch. Ill will definitely keep at it. I think whenever I have trouble with something it makes me more determined to do it. My wife says I get a little obsessed!

Thanks again for the help!

[Don Robinson]

Your torch should work fine.