Experiments With Flex

[duckbillclinton]

1 hour ago, InesF said:

Hi @duckbillclinton.

 

I get the impression, we are talking about totally different things, here.

 

Maybe a recap:

If you heat up iron and shock cool it, it becomes hardened. If you heat up iron and slowly cool it, it becomes softer (annealed).

If you heat up gold, copper, silver, platinum, etc. and shock cool it, it becomes soft (annealed). If you mechanically stress these metals (squeezing, stretching, bending, etc.) they become hard. Annealed gold is flexible to a certain degree but hardened gold is more resistant and needs way more force to be bent.

 

A gold nib is, most probably, in a hardened status from all the steps during production. I never mentioned this for steel. If you heat a gold nib (maybe unintentionally) it may become partly annealed (=soft) and may loose some of its elastic properties. This loss may be critical or may be next to not recognizable - I can't tell in advance, so I'm better safe than sorry. That was the intention of my previous comments.

 

Believe me, I can differentiate between the mentioned precious metals - if not otherwise, at least by their price.

What you can find at Wikipedia ist the elemental properties in the annealed stage, which is not the stage of a squeezed, bent, embossed ... whatever ... fountain pen nib!

Iron, or wrought iron, or pure iron, can not be shocked cool hardened.  It remains in ferritic state, it is the same as ferritic stainless steel which I had demonstrated annealing and shock cooling from the previous post, the shocked cooled nib (Jinhao) remain annealed.  Shock cooling on ferritic steel or wrought iron can NOT harden the subject, annealed status remain unchanged, it's the same as slow cooling.   Same applies to austenite stainless steel.  Cold work indeed can increase hardness and toughness due to stress (dislocation of crystal structure) applied to the metal, however annealing will undo all that.   Annealing require a certain temperature with a certain duration of time.  Time/ duration is crucial.  The platinum wire you worked with maybe had worked hardened, and the gold wire you worked with maybe was annealed, but it has nothing to do with platinum's softness, because platinum is not brittle, or else how could it be cold worked to jewelry.  Iridium is expensive as well, but can it be annealed and cold hammered to shape?  When we are talking about 2 metals' softness/ hardness, we always assume they are both annealed.

[mizgeorge]

56 minutes ago, duckbillclinton said:

because platinum is not brittle

Actually, that's not the case at all. Platinum is harder than gold, but not as malleable. The two should not be confused (speaking as a jeweller!)

[duckbillclinton]

14 minutes ago, mizgeorge said:

Actually, that's not the case at all. Platinum is harder than gold, but not as malleable. The two should not be confused (speaking as a jeweller!)

That depends on how you define brittleness.  Tungsten, chromium, iridium in their pure and just-done-hot-casted form, 1 hard hammer strike will shatter them in pieces, because their mohs hardness is 6.5 and above (diamond is at max of 10).  Gold and platinum on the other hand, after they are hot casted and cooled, hard hammer strike only cause deformation.  Maybe in your definition, less malleable means brittle, in that case, Ines' views are fine, and I don't have a problem with that.

 

Annealing doesn't solely depend on temperature, time has to do its magic also.  In addition, chemical composition of the treated subject is also crucial. 

 

The common view of shock cooling "iron" will make it harder, is based on observation of traditional medium to high carbon steel quenching.  Pure iron/ wrought iron has no such thing, this can be easily validated with experienced/ seasoned  blacksmith/ bladesmith.  I am absolutely sure... as you are a good jeweler and artist, you must know at least a few good blacksmiths in your circles as well, please check with them. 

 

On the other hand though, regarding heated precious jewelry metals/ alloys (raised temperature to red hot, orange hot, or yellow hot)... at that point... whether shock cooling or air cooling will actually harden or soften the subject, there are always conflicting answers on the web. 

 

This is simply due to the fact that chemical composition of the subject is always overlooked. 

 

(Now let's do some Not so scientific explanation.) 12k, 14k, 18k gold (alloyed gold) usually contain certain amount of copper, when these k-gold are air cooled, copper content will precipitate inside the alloy, causing the internal crystal structure to be strained, and hence, we observed hardened k-gold after air cool.  Water shock cooling, on the other hand, quickly interrupts the copper precipitation, hence k-gold remain soft.  Now, let's look at pure 24k gold, since there are no alloying elements, in this case, air cooling or water shock cooling play little differences, well, from metallurgy and material science, heating metal to just a bit past recrystallization then rapid cooling does make metal's grain (crystal) sized smaller, it does improve hardness and toughness by a tiny amount (not noticeable for pure gold), but the waiting time (for pure gold to air cooled) outweighs the benefit gained, so let's just shock cool it. 

 

Regarding grinding a nib whether will anneal it or not, let's answer the question of which part of the nib are we grinding? 

 

The tip? Yes? Then we must be talking about the "iridium point", right?  If so, one must not forget it was resistance welded to the nib, and for a split of second, the welding spot was in liquid state.  It's  fully recrystallized and followed with air cooling, now was it hardened or annealed?  Pure copper's recrystallization temperature is at least 200 Celsius degrees, that seems low, but that's the minimum temperature, meaning, in order for annealing to take place at this temperature, a very very long time is required.  Higher temperature required less time to recrystallize (anneal).  When I grind my tip, like Amadeus mentioned, I always blow a little bit of air to cool it, or I lift the nib up and touch the tip with my fingers to cool it, yes there was a tiny bit of burning sensation, but it never left a burn mark or blister on my finger, meaning the temperature is at most around 70 ish Celsius degrees.  Such low temperature and such short time frame, how could annealing ever be able to take place???

 

Now, on to the nib body grinding and thinning, I do them by grabbing the nib directly with my fingers on one hand, and dremel in the other hand.  All my flex nib are carefully shape to the desired design following pre-drawn blue shadows from a permanent marker, so I do it step by step with patience (meaning I pause from time to time).  There are quite a bit of mild burning sensation and pain I can feel during grinding, but I never get a burn nor a blister.  It's the same result, grinding of the nib (even by using a tool to clamp it) is not going to anneal the nib if you Don't overdo the grinding with a long duration.  Nib temperature will never reach 100 Celsius degrees if you do it right.

 

[duckbillclinton]

1 hour ago, mizgeorge said:

Actually, that's not the case at all. Platinum is harder than gold, but not as malleable. The two should not be confused (speaking as a jeweller!)

Oh, I think I missed one important factor, if Ines is a nibmeisteress, then water cooling during grinding is very much needed.  This has nothing to do with gender. Rather, professional nibmeisters need to do a large amount of order, they used custom made vise, clamps, and other tools, nibs are grinded with high speed, so they can actually get quite hot, water cooling is required.

[mizgeorge]

I just wrote a long reply, but I'm not going to bother posting it. There is more than enough good information early on in this thread, and on many others, for anyone wishing to try some nib modification.

 

I remain slightly mystified about what you're trying to add to the discussion, other than to appear out of nowhere, with no introduction and try to tell us we're all doing it wrong and that your scientific and research credentials make you better than us. 

 

There are better ways to troll a board - so far you've only managed to achieve a mild level of antagonism.

[duckbillclinton]

On 8/6/2021 at 8:33 PM, lianali007 said:

 

Wait, rewind, I've been modding my plastic feeds by hand with an exacto knife. You take the channel all the way down to the end of the feed? 

 

Also, thank you for the crazy glue repair! I will have a bunch of feeds I can salvage from when I didn't understand the limits of capillary action.

Yes, I did take the channel to the end.  The feed for flex writing required lots of ink, and it's modded almost close to leaking.

 

[duckbillclinton]

On 8/2/2021 at 10:53 PM, SoulSamurai said:

 

Just an FYI, Tamiya has an engraving tool with replaceable cutting heads that come in sizes starting from 0.1mm. It might be a more controlled way to cut 0.2mm channels. Check out the review here: https://www.scalespot.com/reviews/tools/tamiya-engraver/review.htm.

 

 

I can not thank you more for suggesting such a GREAT tool for me. 

 

With such tool, the last question on my feed mod has been properly answered.  Previously, the tools I used couldn't create good quality ink channels with consistency, and ink flow varies quite a bit between mods.  Now, with your suggestion, ink flow can be made scarily large, and I am completely stunned.

 

Last Saturday was the most enjoyable moment in recent times for me.  My online ordering of 4x engraving knives arrived.  2 of them are 0.1mm, and the other 2 are 0.2mm.  Within 15 seconds of use, I chipped (broke) one of the 0.1mm knives since I am not familiar with using them.  After a bit of tinkering, I realized that 0.2mm engraving knife is the only size us flex nib modders required.  The 0.1mm one is too thin and fragile, it easily gets jammed up in the factory cut ink channels, and just a little twist motion will snap the blade.  The 0.2mm is much stronger, but initially, it is hard to get inside the factory cut channels.  My suggestion would be using a utility knife first... run straight through the factory cut channels one or two times to widen the channel top, then insert the 0.2mm engraving knife blade to deepen the channels.

 

I am buying an electronic microscope online now, so that super close-up images of the modded feed can be taken, I can finally share with everyone on every details about my feed mod which is a must have for a flex nib.

Edited August 10, 2021 by duckbillclinton

[SoulSamurai]

I'm glad it helped! I've also found the 0.1mm blade to be very delicate; the one time I tried to use mine I snapped it. I never bothered to replace it as I pretty much never need to engrave lines that fine. Just FYI (in case they didn't have them wherever you bought yours) there are 0.15mm and 0.25mm blades available.

[duckbillclinton]

49 minutes ago, SoulSamurai said:

I'm glad it helped! I've also found the 0.1mm blade to be very delicate; the one time I tried to use mine I snapped it. I never bothered to replace it as I pretty much never need to engrave lines that fine. Just FYI (in case they didn't have them wherever you bought yours) there are 0.15mm and 0.25mm blades available.

0.2mm blade is GOLD, tough and perfect for the job!!!😋😋😋  0.25mm blade might be a bit too wide, thinner ink could leak like mad.  😅 

[duckbillclinton]

On 8/10/2021 at 1:45 AM, mizgeorge said:

I just wrote a long reply, but I'm not going to bother posting it. There is more than enough good information early on in this thread, and on many others, for anyone wishing to try some nib modification.

 

I remain slightly mystified about what you're trying to add to the discussion, other than to appear out of nowhere, with no introduction and try to tell us we're all doing it wrong and that your scientific and research credentials make you better than us. 

 

There are better ways to troll a board - so far you've only managed to achieve a mild level of antagonism.

Don't be mad, Mizzy.  If I had upset you, then you have my most sincere apologies.  Please bear with me.

 

I was replying back to you with a long post, took me nearly 4 hours to organize the whole thing, and only to loose the whole thing with one wrong click.  In the post, I explained everything in details, including consultation with one of my good jeweler friend (20 years in jewelry crafting), data validation from material science database websites.  It turned out that Ines is right about platinum's "brittleness" in the sense of under cold work stress.  On the other hand, both platinum and gold are indeed soft in fully annealed status.  There's no embarrassment for me to admit I made a mistake, as science will always win out.  I will redo the reply tomorrow when I have more free time, and then you will see what my jeweler say about this subject, my personal experience with pure platinum wire, and why material science data shows Ines is correct about cold work stress on platinum.

 

Regarding my findings on flex nib mod though, as I have very limited time, I will eventually share my findings with everyone.  I am not trolling, LOL.  It's going to be a while as I have already explained to others I need to redo my experiments to validate the results.  Ink film problem for a flex nib is tough, trust me on this.  My findings are not must haves for making flex nibs, as they had been made and sold for more than a century.  However, my findings can help to make flex nib better, especially for home DIYers, they will have better success rate on modding, and nibs can cold start writing a wide stroke almost always with success but not railroading.

 

Even for now, a near 50 year old kid like me is still playing with soap bubbles and films.  I am trying to find out more on keeping the ink film stable.  Below are just 2 samples I played with during my lunch break today. 

 

Photo 1 and 2 are a "wand" made with iron wire and twisty tide, it simulates and validates ink film being stretched... just like... we press down the nib to force open the tines, ink film gets stretched out, getting thinner, ink film's color fades out, and eventually get so thin that, it become a black film which reflects no light, and looking fully transparent since the ambient light under the nib is darker than the surroundings, at this moment, we still can continue our wide stroke, if we further open the tines, the film bursts, and comes the railroading.  If you pay attention to the shape of my wand, a spike sticks out in one of the half moon.  It very much simulates the situation of cross-flex mod, and explains why vintage flex nib's new moon shape or heart shape breath hole can only take certain orientation.  It also explains why cross-flex design and Pilot's vintage steel nib V shape breath hole design is BAD.  What? For real?  These are related?  You will see once I publish my findings in the near future.  For those who are really smart in physics and math, I will give some hints, angular velocity and linear velocity difference and local stress/ pressure on ink film, ink/ soap film rupture speed, Marangoni effect. 

 

Photo 3 is a thin plastic I cut from a small zip lock bag.  I cut a hole it it, and use it to validate if thickness of the surrounding/ supporting edge of a soap/ ink film will affect its stability and forming.  This will apply to how thin we can grind our nibs.  

[duckbillclinton]

On 8/10/2021 at 1:45 AM, mizgeorge said:

I just wrote a long reply, but I'm not going to bother posting it. There is more than enough good information early on in this thread, and on many others, for anyone wishing to try some nib modification.

 

I remain slightly mystified about what you're trying to add to the discussion, other than to appear out of nowhere, with no introduction and try to tell us we're all doing it wrong and that your scientific and research credentials make you better than us. 

 

There are better ways to troll a board - so far you've only managed to achieve a mild level of antagonism.

Photo 1 and 2, and 3

 

[mizgeorge]

5 hours ago, duckbillclinton said:

Mizzy

If you know my given name, please use it.

Otherwise, please do me the courtesy of using my screen name. 

[MarioR81]

Ok, I took a leap on my kakuno F. It's one of my most reliable nibs so really didn't want to mess it up. Increased the cut on the slit and a little "bite" on the sides. I had to run a couple passes of very fine sand paper on the slit near the tip. It improved the line variation with same pressure but I was expecting a little more. But maybe it's too much to ask for this type of steel nib.

[duckbillclinton]

13 hours ago, MarioR81 said:

Ok, I took a leap on my kakuno F. It's one of my most reliable nibs so really didn't want to mess it up. Increased the cut on the slit and a little "bite" on the sides. I had to run a couple passes of very fine sand paper on the slit near the tip. It improved the line variation with same pressure but I was expecting a little more. But maybe it's too much to ask for this type of steel nib.

Don't make any more changes further.  I will give you some suggestions with photos/ drawings in the coming week... Been really busy so I couldn't even write any replies previously mentioned to others.

[MarioR81]

thanks

[Pen Engineer]

On 8/9/2021 at 2:38 AM, InesF said:

I always have this in mind when grinding a gold nib - and that's the reason I do the grinding with water cooling.

ever thought of grinding under water? 🐟

[Pen Engineer]

On 8/9/2021 at 2:48 AM, InesF said:

The gold wires can be bent quite often and although they became harder, they do not suffer. Iridium and platinum wires can be bent two times, the third time they break.

most nibs are made from alloys, which effects elasticity, plasticity and work hardening enormously!   The gold alloy for nibs actually does work-harden, which is essential for making a nib, any nib, flex or nail.

[Frank C]

6 hours ago, Pen Engineer said:

most nibs are made from alloys, which effects elasticity, plasticity and work hardening enormously!   The gold alloy for nibs actually does work-harden, which is essential for making a nib, any nib, flex or nail.

This is a little off topic, but I want to take this opportunity to thank Pen Engineer, Amadeus W., for his Magnum Opus, the Fountain Pen Design website, referenced above. It is a tremendous resource for those of us who want to understand how fountain pens work. I highly recommend it. 

[InesF]

On 8/16/2021 at 10:49 AM, Pen Engineer said:

ever thought of grinding under water? 🐟

Yes! 🧜‍♀️

The 12V Dremel should not harm me when submerged in the bath tube. However, I had a hard time to position myself correctly and the diving goggles changed my vision for the right distance so that I accidentally ground my fingernails instead of the nib ....👎

😉

[InesF]

On 8/16/2021 at 10:54 AM, Pen Engineer said:

The gold alloy for nibs actually does work-harden, which is essential for making a nib, any nib, flex or nail.

Yes, that is my worry about accidentally heating (and annealing) a gold nib.

It's too costly to do empirical experiments with gold nibs - for those, I'm always better safe than sorry.