Stripped cap threads

[extrafine]

I have several pens with stripped (or at least loose) cap threads.

 

One where the cap didn't hold at all I fixed temporarily by putting a piece of scotch tape in there. Works surprisingly well. Another, where the threads were stripped on one side of the cap only (how does that happen?), I put a bit of shellac, and all was well. I imagine that both of these "solutions" will wear out, but at least they're not too aggressive and more-or-less reversible.

 

Any other suggestions?

[david i]

I have several pens with stripped (or at least loose) cap threads.

 

One where the cap didn't hold at all I fixed temporarily by putting a piece of scotch tape in there. Works surprisingly well. Another, where the threads were stripped on one side of the cap only (how does that happen?), I put a bit of shellac, and all was well. I imagine that both of these "solutions" will wear out, but at least they're not too aggressive and more-or-less reversible.

 

Any other suggestions?

 

 

Might wish to discuss with Ron Zorn who can enhance the barrel thread contour without adding any material at all to pen. Often sufficient to allow cap closure to occur, but cannot know until try. Tricky procedure.

 

-david

 

 

[Ron Z]

It is indeed a tricky procedure, and not for the inexperienced. It involves expanding the plastic of the barrel so that the threads of the barrel engage the cap threads. Some plastics, and some barrels can handle this better than others, some may crack. If successful, some barrels will then need a sleeve between the section and barrel so that the section doesn't fall out of the pen.

 

Sometimes you can trim the inner cap so that the barrel goes farther into the cap to engage the cap threads farther in. Sometimes you need both procedures. In any case, based on experience, I believe that a lathe is necessary in most cases for it to work.

 

And then there are some cases that are just hopeless.

[extrafine]

Both of these procedures seem too complicated for me. I'm going to have to stick to what I've done, or send them out.

 

[i already have one pen out to you, but for a different problem...]

 

Thanks!

[Buzz J]

It is indeed a tricky procedure, and not for the inexperienced. It involves expanding the plastic of the barrel so that the threads of the barrel engage the cap threads. Some plastics, and some barrels can handle this better than others, some may crack. If successful, some barrels will then need a sleeve between the section and barrel so that the section doesn't fall out of the pen.

 

Sometimes you can trim the inner cap so that the barrel goes farther into the cap to engage the cap threads farther in. Sometimes you need both procedures. In any case, based on experience, I believe that a lathe is necessary in most cases for it to work.

 

And then there are some cases that are just hopeless.

 

Ron,

Would a similar approach work for terminally loose Skyline derbies? ie expand the threaded inner cap?

John

[Ron Z]

It is indeed a tricky procedure, and not for the inexperienced. It involves expanding the plastic of the barrel so that the threads of the barrel engage the cap threads. Some plastics, and some barrels can handle this better than others, some may crack. If successful, some barrels will then need a sleeve between the section and barrel so that the section doesn't fall out of the pen.

 

Sometimes you can trim the inner cap so that the barrel goes farther into the cap to engage the cap threads farther in. Sometimes you need both procedures. In any case, based on experience, I believe that a lathe is necessary in most cases for it to work.

 

And then there are some cases that are just hopeless.

 

Ron,

Would a similar approach work for terminally loose Skyline derbies? ie expand the threaded inner cap?

John

 

It will work, but one has to be very careful when doing that - it's easy to crack the inner cap. I know that Richard doesn't like to expand the inner cap for that reason. It's a risk that I'm willing to take.

 

The derby was usually threaded onto the inner cap, which is usually hard rubber, and secured with shellac. The plastic of the cap liner shrinks, which is why the inner cap jumps threads.

 

Paper, or tape is an option. The problem with that is that it pushes the inner cap, and therefore the derby to one side, so is off center when you screw the inner cap in. Ya makes your choices.....

[MRubee]

I have an Omas Milford with a cap that screws on and when it gets to the point where its suposed to be tight it clicks and is loose again. Im assuming either the barrel expanded or the section shrunk or its stripped. I see the tape fix, other solutions? Im curious about this thread expansion that Ron Z is talking about. Who could do that for me because Im certainly not qualified.

[RoSpectre]

I have a similar problem on an old Pelikan 400... doesnt click loose which sounds like a tougher problem, but cap is still loose when fully tightened.

 

Knowing that the application of gunk is usually not advised, would a drop of shellac on the caps threads serve to tighten things up? That's my plan but I'm happy to be talked out of it.