# Kitless Fountain Pen in Autumn Flexigran and Italian Urushi Resin



## JPMcConnel (Dec 8, 2014)

I designed this fountain pen in Autumn Flexigran and Italian Urushi red resin (both from Richard Greenwald) as more of a desk pen. It is 6.5" long and does not post, nor does it have a clip. I find the pens I gravitate to are a little longer and have a tapered body so they fit nicely in the area of the hand between the joint of the thumb and first finger (hope I got that right). The pen body has a triple thread 13mm X 8 thread so there are many positions for the cap and pen body junction; I managed to have two sets of those positions line up. The red finials are highlights and compliment the red section. With finials this pen can be made with a clip. Flexigran is a pleasure to work with; it does require care in producing a nice finish, but I think the results are worth it.


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## mredburn (Dec 8, 2014)

Nicely done.


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## Jim15 (Dec 8, 2014)

Another beautiful pen.


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## Charlie_W (Dec 8, 2014)

Great job on the pen!  Wifey likes the red accents!


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## lorbay (Dec 8, 2014)

Nice colour. Actually nice pen. 
Lin


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## SteveG (Dec 9, 2014)

Very nice work on this one! I noticed the sheen is less (or lower) on the barrels vs the end caps of different material. Is that purely by intent and design, or more the result of just being the outcome you get with Flexigran? I have tried that material, and have not been able to finish it out to a really high sheen. So I wondered if you experienced the same limitation?


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## tgsean (Dec 9, 2014)

Fantastic pen mate, well done


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## JPMcConnel (Dec 9, 2014)

*Flexigran: why is the sheen different?*



SteveG said:


> Very nice work on this one! I noticed the sheen is less (or lower) on the barrels vs the end caps of different material. Is that purely by intent and design, or more the result of just being the outcome you get with Flexigran? I have tried that material, and have not been able to finish it out to a really high sheen. So I wondered if you experienced the same limitation?



I am not an expert on resins, but I will hazard a guess that the density of the material and the strength of its molecular chains, and their bonding, have an effect on how well it takes a sheen. The italian resin has relatively strong molecular chains (I think better than polyester resin or some others) but it can be brittle if you force it, e.g., try to turn too much material off in one pass or too quickly, or cut too thin a wall section and it will chip. It may not chip as easily as polyester resin, but it will chip. It takes a nice sheen, perhaps because its less strong molecular chains give up material easily and cleanly from the ends of molecular chains allowing it to be smoothed down uniformly to produce a nice sheen.

What I have experienced with the very "tough" and molecularly dense resins like FLEXIGRAN and alumilite is their much appreciated ability to be threaded with taps and dies and lack of brittleness seems to come at the expense of easily producing the desired eye popping sheen. In other words, when these materials are sanded and buffed, instead of loosing material to a uniform level of smoothness, the top layer of these tough molecular chains gets frayed, like a nylon rope that is coming apart, until we achieve what we think is a dull sheen. I also think the dyes and pigments have some bearing on the sheen produced. In my experience it is harder to produce a sheen with some colors and concentrations of color; the blue / gold flexigran has been the best-to-polish flexigran for me.  

So, I tend to equate increasing brittleness with an increasing ability to take an easy, but eye catching sheen, but at the expense of machinability. Conversely, the more machinable a resin becomes the harder to achieve the same sheen even as the desirable mechanical properties improve. And cost goes up as machinability improves, generally. To be honest, I find the sheen on flexigran and alumilite more appealing because it is subdued and doesn't have that plastic look.  But that is just my opinion as has been all of the above. Hope this helped and thanks for your question on something I have thought about a lot. I am still working on a surface prep protocol for flexigran and alumilite to give me the "best" finish, LOL.


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## SteveG (Dec 9, 2014)

Well James, thanks for the detailed response and discussion on pen materials properties. You added to my knowledge base for pen making, which is appreciated. Your offering of details ALMOST made my brain hurt, but I got through it OK! I do agree that not every pen needs to be super shiny to be good, and this is a perfect example of that premise. Very nice pen!

As an additional observation, I have had success with achieving a very high sheen with Alumilite, but not so with the Flexigran. R. Greenwald states that it is possible. I obviously have things to learn here.


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## MikeL (Dec 11, 2014)

Wonderful design and great craftsmanship.


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## Brooks803 (Dec 11, 2014)

JPMcConnel said:


> SteveG said:
> 
> 
> > Very nice work on this one! I noticed the sheen is less (or lower) on the barrels vs the end caps of different material. Is that purely by intent and design, or more the result of just being the outcome you get with Flexigran? I have tried that material, and have not been able to finish it out to a really high sheen. So I wondered if you experienced the same limitation?
> ...


 
That's a great explanation but if I may...

harder the material = more difficult to machine/thread but higher the gloss
softer the material = Easier to machine/thread but very difficult to get a high gloss

I like your pen btw! The shape of the front section is my fav part.


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## JPMcConnel (Dec 11, 2014)

Brooks803 said:


> JPMcConnel said:
> 
> 
> > SteveG said:
> ...



Can't disagree with you on the hardness part. I don't think of alumilite and flexigran as soft; the idea of tough comes to mind with some elasticity. This elasticity is what I think makes it hard to polish because it "scuffs" rather than abrades. Just my opinion. Thanks for the compliment.


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## JPMcConnel (Dec 12, 2014)

Back again!

As usual, one of our IAP members already addressed the differences between polyester and polyurethane (alumilite) resins. Please see:

http://www.penturners.org/wiki/Alumilite_and_Poly_Ester_Resin_properties
Alumilite and Poly Ester Resin properties
Attribution: Curtis O Seebeck aka MesquiteMan

What I thought was interesting is on the Shore D hardness scale Alumilite ranges from 72 - 80; poly ester is Shore D 78. Elongation, a measure of brittleness, for polyester is 1.5%, while alumilite varies between 7% - 12% depending on the Alumilite used. See the articles below for more extensive discussions of these two products.

Other very good articles on this topic are:

https://www.artmolds.com/polyurethane

Polyurethane Resin vs Polyesther Resin


http://www.douglasandsturgess.com/HowTo/Introduction-to-resins-Howto.pdf

Which Resin is Right For Me?


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