You know that feeling, when you make a BIG mistake...

Salem Straub

Salem Straub

Joined
Oct 20, 2008
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5,547
Have you ever had that feeling when you numbly recoil from the mess you have just made from what was very recently a nearly finished knife?

Check this out. I'm building this TI, S30V framelock. I nearly have it done. It's a working knife, locks up solid, a nice piece, only the pocket clip left to install and some sanding on the frame.

I drill the pocket clip holes. #51 bit for 2-56 screw. I start tapping. Although I'm very careful, the tap snaps in the hole. (.162 TI, next time I'll use a #52 for TI this thick.) I try to get the tap out, to no avail. My only option: to dissolve the tap in ferric chloride. It goes into the bath. FFW four days.

The full strength Ferric bath has still not dissolved the tap fully. I am, however, able to knock the tap remnant out with a small punch. I clean the hole up, and get some threads into it. I now have one clip hole left to tap.

VERY carefully, I get the tap almost completely through the TI. Then, I break the $#% tap off in the hole.

With a sense of unreality, I realize that despite KNOWING it would easily break, and TRYING not to do it, I am back to square one.

I kind of lose it. I'm not waiting another four days to get this one out. So I decide to try something I have previously only heard about: heat the tap up with a torch and use the oxygen to burn the steel tap fragment out of the TI.
All I can say is, I wouldn't recommend trying it on something you already have several hours invested into. At least not in that frame of mind.

A minute later, I'm backing away in abject fury and shock, faced with the disgusting spectacle of the lock side of the frame irreparably marred by a large foamy crater in the TI.

Two hours later, I'm able to say this: at least I can still use that ruined piece as a pattern for the re-build. More TI is on the way. And don't work angry on a knife for which you have taken a deposit.

You guys ever feel this way? :eek:
 
Damn Salem, can't say as I ever have. ;)

Make sure you get that #52 bit as well! Is there anything else can change that might improve your odds? Use a different kind of bit or bit tip/angle? Slower or faster drill rotation? Or...?

What no photos? Are you hoping if you don't show us any it will be like it didn't happen?! :D

Keep us posted.

All the best, Phil
 
yea I know the feeling of "when you make a BIG mistake..." but it usualy ends up with me trying to stop the bleeding.
 
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Okay Phil, here's a couple pics.

I mean, look at this. Are you kidding me?

I'm gonna try a #52 and tap in some scrap TI of the same thickness. If that don't work, or maybe even if it does, I'll maybe drill the clip holes through the new frame piece with a #51, then counter bore halfway into the same holes from the back with a clearance bit. Then tap. That way I'd only be actually tapping about .080 thickness. Plenty of thread to hold a pocket clip with three screws.

If I made another handle half and ruined that one, I'd probably die.

IMG_5611.jpg


IMG_5610.jpg
 
Are you using a bottom or through tap?

I'm 66 and have had ever opportunity to experience a run of bad luck; so yes.:)

Bummer!:eek::grumpy:
 
I have done things a different way, even though I know I should have done it a certain way, and it hardly ever works out well for me.

I have also repeated the exact same mistake twice in a row.


What kind of tap are you using?

I like spiral point taps made for machine use
They have more resistance to twisting off then hand taps

Are you taping by hand?
or are you using a tapping head, or at least holding the tap in a holder, or drill press for good alignment.
 
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I've done that very thing in a very large and expensive automated drilling machine I'd been building for weeks. Bad move. This was about 15 years ago. I've been using Moly-Dee when I tap holes ever since.
 
Hot dang! Maybe if you had used a bigger cutting torch?! :eek:

I guess we'll have to put this almost up there with Sam hooking up an electric motor to drive a formerly treadle powered old sandstone grinding wheel, then promptly having it explode pieces through the shop roof and walls.

Well, come to think of it, I guess your move isn't quite on par with Sam's. :eek:

Show us the rest of the knife too. That way we'll remember the good stuff! :)
 
Dude I know exacty how you feel, I have done the same thing at least 6 time on some of these dang frame locks until I started using a 52 drill bit.

My condolences :)
 
Ha ha, I remember when he did that (old sandstone grinding wheel). Kinda funny in retrospect. He manned up to it too. :thumbup:

I'll point out that using an oversize drill or very short thread engagement may leave adequate thread strength in the titanium - but you have to remember that the fastener you're using gets the same amount of thread engagement... So you still need at least three full threads, preferably five, and no less than 60% thread depth or the screw can strip.

A sharp high quality HSS tap, in a correctly sized hole that is properly aligned and lubricated with a high pressure tap lube will work every-single-freakin-time.

The yield strength of most titanium is probably 180,000 PSI. What is the film strength of the lube you're using? I have found that can make a big difference.
 
Been there and done things like that. I would recommend however that you not go with a #52 (.0635") bit as it is actually smaller than a #51(.067"). You might want to use either a 1.75mm (.0689") or a #50 (.07"). By my charts the #50 is what is recommended for a 2-56 or 2-64 tap. Also buy good taps as ti is a real pain to tap as you found out. Use the moly d as Nathan recommended or a lube that is designed specifically for ti.
 
Dammit, Carl, OUCH!!!

By god, you are right Chuck. I probably will go to a #50, then.

Nathan, good food for thought. I confess that I was merely using WD40 for lube. I did use a brand new tap; it was a taper HSS straight flute tap. Maybe I'll go with a spiral tap and at least some Tap Magic.

I was using a hand tapper that I made out of a drill press. The only problem is that it can be difficult to actually feel how much pressure you are giving the tap due to the leverage of the crank.

Phil, I will post pics when the knife is done. Hopefully very soon.
 
Always listen to the small still voice inside your head telling you ,this might not be a good idea.
 
Salem Straub said:
I confess that I was merely using WD40 for lube. I did use a brand new tap; it was a taper HSS straight flute tap. Maybe I'll go with a spiral tap and at least some Tap Magic.

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Click to expand...

I think that is likely your problem.

WD-40 is almost useless as a lubricant and is only useful as a cutting fluid in very low pressure applications such as light cuts in aluminum or in applications where you want a low film strength like when sanding or stoning. It has no EP qualities to speak of and low lubricity as well. It does work well as a water displacer though.

The ability to feel so you can back off becomes less important when you no longer need to back off, which is what a good tap and good lube and good alignment can frequently achieve for you.
 
I know the feeling. Been there…..

I use #50 drill and a tin coated tap, 2 flute
whit Moly dee.

Wend I building a knife,
There is nothing more
Stressful than the tapping operation,
Now I drill and tap before cut the lock or anything else

Best regards
 
Salem, The only thing you can do now is torch several more spots like that one and call it "Special Torch Treatment". You could charge extra for that.
 
I have done things just as bad with some very expensive and rare stone so this type of self induced mess does not only apply to working the metal....

I have learned to not wear my nytril gloves while lapping flat the back so stone scales on a 12 inch rotating lap. :eek:
 
Believe me Bruce, I've managed to turn a few mistakes around by "altering design" before- for a split second the impulse that it might be possible in this case asserted itself. That was still during the brief disbelief phase, though.

I guess I could tell him it's "torch coloring" taken to a whole new level...

Yeah, so right on guys, good advice, I'm going at the next one with a better tap, better cutting lube, and a #50 drill. And perhaps I will drill and tap everywhere before cutting the lock.
 
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