Nib tuning questions

[azkid]

I've run across a few new nibs that have hard starting issues (Jinhao, Lamy, Knox) -- where they often fail to start words right away, but excessive pressure gets them to start.

It seems the problem nibs have a larger baby's bottom gap than pens that never fail to start.

Does baby's bottom serve any purpose, such as establishing vertical line width?

If not, then why is it present on new nibs? Manufacturers could eliminate it much easier than creating it, right? Surely it serves a purpose.

Also, I notice that new, hard starting nibs that I've encountered are improved significantly by using 9 micron to 30 micron Zona polishing paper on them.

But they tend to hard start again if I polish them with 3 micron or finer.

Any ideas why? I have a theory but wanted to see what others say.

[Wuddus]

Interested to see where this goes....

[Farmboy]

Interested to see where this goes....

Should we ask what kind of ink and paper is being used?

[dfo]

I've run across a few new nibs that have hard starting issues (Jinhao, Lamy, Knox) -- where they often fail to start words right away, but excessive pressure gets them to start.

It seems the problem nibs have a larger baby's bottom gap than pens that never fail to start.

Does baby's bottom serve any purpose, such as establishing vertical line width?

If not, then why is it present on new nibs? Manufacturers could eliminate it much easier than creating it, right? Surely it serves a purpose.

Also, I notice that new, hard starting nibs that I've encountered are improved significantly by using 9 micron to 30 micron Zona polishing paper on them.

But they tend to hard start again if I polish them with 3 micron or finer.

Any ideas why? I have a theory but wanted to see what others say.

The simple answer, to why pens have baby's bottom, is over-polishing by the manufacturer. Baby's bottom does not serve a purpose in regard to line width. It does tend to make a nib smoother but more susceptible to hard starting. That said, hard starting can be caused by a variety of other reasons. I had a Jinhao that would hard start with saturated inks, but it would write fine with a dry ink such as Pelikan Blue-Black.

As alluded to by Farmboy, the type of ink and paper can lead to hard starting.

[azkid]

I too have experienced the influence of paper and ink on hard starting.

Take the Knox for example. While troubleshooting, I tried multiple brands of paper, using Pelikan 4001 black. Said be dry-writing, I know. Yet I have dry nibs that always start reliably with this ink.

Even so, I made sure ink flow was adequate. In fact, the Knox was writing way too wet. Yet still hard starting. Go figure.

What cured it was gentle application of polishing papers as mentioned, attempting to reduce baby's bottom.

One thing I don't understand is how do manufacturers manage to remove material from the inner edge of the nib when polishing? That doesn't seem to be a problem for me.

[dfo]

One thing I don't understand is how do manufacturers manage to remove material from the inner edge of the nib when polishing? That doesn't seem to be a problem for me.

It happens much in the same way an inexperienced person (like me) might try to smooth out a nib. They press too hard on the nib opening up the tines and polishing the inner portions of tipping material or by twisting the nib while pressing down onto the polishing paper/polishing wheel. One tine might open up and become over polished. It is sad that some high-end companies send fountain pens with baby's bottom.

Not every company can be perfect like Aurora or Sailor. -__-

[dneal]

I've run across a few new nibs that have hard starting issues (Jinhao, Lamy, Knox) -- where they often fail to start words right away, but excessive pressure gets them to start.

It seems the problem nibs have a larger baby's bottom gap than pens that never fail to start.

Does baby's bottom serve any purpose, such as establishing vertical line width?

Nope. It just a wrong way to make a smooth nib. Vertical line width is determined by the width of the tipping (that touches the paper)

If not, then why is it present on new nibs? Manufacturers could eliminate it much easier than creating it, right? Surely it serves a purpose.

It's easy to do when you are using a spinning wheel. There's a Lamy factory video where the worker refers to creating a nib as smooth as a baby's bottom. She's also creating a baby's bottom (poor writer). She's testing for smoothness with a dry nib on paper, and not accounting for flow. This seems to be common among German pen companies.

Also, I notice that new, hard starting nibs that I've encountered are improved significantly by using 9 micron to 30 micron Zona polishing paper on them.

But they tend to hard start again if I polish them with 3 micron or finer.

Any ideas why? I have a theory but wanted to see what others say.

There are a few reasons for a pen being a hard starter... with baby bottom being a common reason.

At the end of the day, something is interrupting the capillary effect. Baby bottom prevents the ink from touching the paper. A nib that has too much of a gap between the underside of the nib and the end of the feed channel can interrupt the capillary effect. A clogged feed channel that doesn't let ink flow or air enter the body can do it.

I can cause the same problem with over polishing, even though I don't create baby bottom. I believe the tip is so smooth that it resists the capillary effect, which why a single stroke on a slightly more abrasive grit can correct the problem.

For folks that may be reading this thread, Richard Binder's Nib Tuning Workshop Notes is probably the best starting reference on the internet.

[azkid]

Ok that makes sense thanks @dfo!

And thanks all for your info and insights.

I spoke too soon about the Knox nib. It's better but still having issues. I am going to wait to do anything more until my fancy new loupe arrives in a few days.

[dneal]

Ok that makes sense thanks @dfo!

And thanks all for your info and insights.

I spoke too soon about the Knox nib. It's better but still having issues. I am going to wait to do anything more until my fancy new loupe arrives in a few days.

Smoothing the inside edge of a nib is important to having a smooth nib. Overdoing it creates baby bottom. Place two fingers on the edge of a table, and press down firmly. Then rotate your hand slightly clockwise or counter clockwise. Notice how the portion of your fingertips that is actually touching the table changes?

Think of those two fingers as being the tines of a nib, with your fingertips being the nib tipping. If you apply pressure when smoothing a nib, and rotate the pen slightly, you can polish the inside of the tipping. That needs to be done. If you do it on an abrasive wheel that's spinning quickly, you remove too much material and create a baby's bottom. The nib won't snag or feel rough, but it won't write worth a damn either.

[azkid]

Such great info-- thanks everyone.

A Belomo loupe arrived recently. Wow! Nice glass -- all my other "optics" are going in the trash.

With the undistorted magnification and increased depth of field, the problem with the Knox was instantly obvious.

The nib cut was off center but the nib grind wasn't placing the ink far from the paper.



That I couldn't see this before goes to show you how bad my other magnifiers are.

Now that this issue is fixed the Knox has written multiple pages without a single hard start. Yay!

Also as a bonus this is one of those pens that heartily resists drying out.

[dneal]

The [Knox] nib cut was off center...

I noticed this too when I bought some Knox pens and nibs to grind a couple for Jon Szanto.

[ahall]

A Belomo loupe arrived recently. Wow! Nice glass -- all my other "optics" are going in the trash.

With the undistorted magnification and increased depth of field, the problem with the Knox was instantly obvious.

What power of magnification is it? I have a cheapie 30x/60x and I have difficulty making out what’s what even at 30x. Yet I’ve read a number of places that 10x should be enough.

[azkid]

It is a 10x but the quality of the optics is quite good-- crystal clear, bright, defined. It is more about the optical quality than the magnification-- something that holds true for binoculars too.

I hold it right up to my eye. I have to use a very bright work light to make out the details. Also it helps to have light and dark backgrounds to hold the nib in front of.

[adhoc]

I’m also using a cheap chinese ”””””60x loupe””””” and now I really gotta buy a proper one.

[azkid]

I was using a single lens, plastic photography loupe. Man that sucked. Going to the Belomo was like upgrading from a worn out 1970's console TV to a new HD4K.

[Larry Barrieau]

Does Belomo have a lighted loupe?

[ahall]

Does Belomo have a lighted loupe?

From looking at http://belomostore.com (and the most cursory Googling) it doesn't look like it.

[Chrissy]

A Belomo loupe arrived recently. Wow! Nice glass -- all my other "optics" are going in the trash.

With the undistorted magnification and increased depth of field, the problem with the Knox was instantly obvious.

What power of magnification is it? I have a cheapie 30x/60x and I have difficulty making out what’s what even at 30x. Yet I’ve read a number of places that 10x should be enough.

30x and 60x have such a narrow depth of field that you can barely see what's what without a really bright light. A 10x or 12x loupe is good enough for nibs and lets you see everything in sharp focus.

[Chrissy]

Does Belomo have a lighted loupe?

You need the Eschenbach Mobilux for a lighted loupe.

[Uncle Fester]

I have a cheap but not nasty LED 15x loupe (no idea if the lens is plastic or glass) from Goulet Pens, not stocked anymore. But they've got this;

https://www.gouletpens.com/products/...11884614975531

Cheers