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Between my own rods and various repairs, I'm sure I've fit more than a couple hundred ferrules over the years, but today I met the devil himself.  He was living inside a 13/64" ferrule made by one of the better-known manufacturers.  I was lapping the male slides to fit the female, but immediately after getting that nice, silky glide and then the "pop," subsequent fits became increasingly tight.

After maybe four or five such tries, I could feel the fit was becoming galled and scratches appeared on the slide.  I'm talkin' scratches that your fingernail could detect.  So I lapped both the males and the female again with 2000 grit to remove the offending areas, and once again got that nice fit I'm looking for - though a little looser.  I inspected the collar and the inside of the female for a "burr" of some sort, but all surfaces were slick as a whistle.  Four or five tries later - same problem.

Further lapping would deteriorate my fit, but since the ferrules were unacceptable as they were, I went ahead anyhow and then swagged the female in my clamping device.  Again, a beautiful fit.  And again, after the same number of tries, the same galling problem.  This time, though, I was careful to watch the indexing of the males to the female to see what area was being affected.  Surprise.  Scratches appeared around the entire circumference of the male slides.  The problem had to be inside the female, since both were similarly affected.

At this point, I knew the ferrules couldn't be salvaged with repeated lapping/swagging operations, so I just went ahead with some real horsepower to beat the devil.  This went on for well over an hour, but I'm writing to say that I lost.

I simply could not figure out what was causing my problem.  Nothing to do but yank the ferrules off and replace them with another set.  So, anyhow, any of you folks ever run into this sort of situation?  I'm thinkin' the problem may have been inherent in that particular run of N/S alloy. 

Possible?  (Bill Harms)

    I went through the same thing last year. Fit them up and maybe a dozen pops later, galling. Had to replace about 3 sets. I tried chamfering both the male end and the female mouth. Didn't seem to help much.

    I hope like hell that the supplier I used didn't have a bad batch.

    I've been trying something else when lapping them. Using WD40 as a lube. After the fit is good, I swab out the WD. It's is amazing how much "black" stuff emerges on the Q tip. I have no idea whether or not this will help in the long run. I haven't had a galling problem since.  (Don Anderson)

      Yep, I kinda suspect a bad batch of alloy, although I don't actually know if this is even possible.

      As one  who has  worked a  good bit  on guns,  I really  hate to use WD-40.  That stuff is good for a lot of applications, but not anything that requires a fine fit on moving parts.  It's a MAJOR dirt-magnet once the vehicle has evaporated.  Still, your idea of using a lubricant of some sort while lapping is generally a good one.  (Bill Harms)

        Like Don I have been using WD40 when lapping the ferrules, but wondered how something like TAP magic cutting fluid would work. Used it a lot when tapping threads in everything from aluminum to stainless. Has anyone tried this?  (Gary Jones)

    I had a very similar problem. I traced my problem to the inside edge of the female. The edge was too sharp and would just slightly cut into the male as it slid in. One question - were the scratches on the male full length or partially covering the slide distance? Anyhow, I solved my problem by slightly chamfering the inside edge of the female side.  (Darryl Hayashida)


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