Friday, 24 May 2013

"Rosin Based" Thread Sealant: Final Mindthots

Appy-polly-loggies for the delay in posting this; here's the results of the thread sealant test using a Parker Frontier and "A.B." brand dark rosin, and a new batch based on "Hidersine" amber rosin.

I'm pretty much happy with how the goo behaves, so the experiments are at an end; time to just use the stuff! To that end, I've reopened the plunger filling Kaigelu 316, and replaced the shellac with section sealant. This should make future disassembly easier; I can't get the manual valve idea out of my head, so ease of access to the pen's insides might come in handy sometime in the future.

Wishing all a pleasant weekend,


Wednesday, 15 May 2013

Rosin Based Thread Sealant: Safety Second!

Here's a second attempt at mixing "rosin based" fountain pen thread sealant, this time eschewing the safety of the bain-marie. This gave encouraging results using a cake of dark "A.B." brand rosin, so, using more heat, I gave the amber coloured "Theodore" rosin another chance too!

After some very helpful input from the wider community of enthusiasts - see these threads at the Fountain Pen Network and Fountain Pen Geeks forums - I think this second batch is an improvement. I've some harder amber rosin on the way, so I will save the results of the Frontier thread test for when that's cooked up.

This has been a fascinating few days! I was a very poor chemistry student, with "a rudimentary knowledge of some areas... [and] great gaps in his understanding", so it's not often I turn my hand to natural philosophy. I've been particularly surprised by the powerful stickiness of the resultant rosin/oil sealant. By means of heat and castor oil, the shade of the original tree's rosin-locked spirit is lent a grasping vitality, as if seeking to lay down roots anew!

Let's Be Careful Out There
This remarkable stickiness is something for the plucky amateur to be cautious of. Though the turpentine is removed, rosin is still flammable. It won't dissolve in water (thanks for that Kristine!), and as shown in the clip above, this mixture is very sticky indeed. Add an open flame to a spillage and one might well say "horrifically" sticky. It brings to mind Anna Comnena's description of a hand held variant of Greek Fire used during a counter-sapping effort  in the defence of Dyrrachium;

"Now this fire was chemically prepared in the following manner. From the pine and other similar evergreen trees they gather resin, which burns easily. This is rubbed with sulphur and introduced into reed tubes. A man blows on it with strong, sustained breath, as though he were playing a pipe, and it then comes in contact with the fire at the end of the tube, bursts into flames and falls like a flash of lightning on the faces of those in front of it."

I don't usually write imperatives in this blog, but with that awful image in mind, please use every precaution if heating this stuff.

Diverting MindThots
 A few millennia-connecting details I found kind of neat during this wee project:

  •  According to the September 1st, 673 - August 31st, 674 entry of the Chronicle of Theophanes, "In this year the expedition of the enemies of God anchored in Thracian territory...At the time Kallinikos, an artificer from Heliopolis, fled to the Romans. He had devised a sea fire which ignited the Arab ships and burned them with all hands." In the entry for 812-813, it's spare underpants time, after "The Bulgars took Mesembria and Debeltos as well, in which places they found thirty-six bronze siphons and not a little of the liquid fire shot through them".
  • 21st Century - describing the qualities of Parker's rosin based thread sealant, Ron Zorn mentions that this sticky stuff will dissolve in naphtha.
  • In the Administrando Imperio, his handy 10th Century guide to empire maintenance, Constantine Poryphyrogenitos warns of the "care and thought you must take in the matter of the liquid fire which is discharged through tubes", and goes on to list the locations of numerous "naphtha wells", "some of them being red, some yellow, and some blackish".
  • Writing in the 1st Century, Pliny references Pytheas' On the Ocean, who reported Germanic tribes using amber for fuel.
  • Anna Comnena's 12th Century Alexiad includes a short note describing the use of tree resin in the preparation of a portable version of "chemically prepared" fire.

Safety first.

See you next time!


Thursday, 9 May 2013

"Rosin Based" Sealant, Further Explorations

Here's the results of today's tests of the homebrew "rosin based" sealant I've been trying to make. More questions than answers, this time around!

Until next time,


Wednesday, 8 May 2013

"Rosin - Based" Fountain Pen Sealant Threadlock Test

In yesterday's post, I had a go making "rosin based" fountain pen thread sealant, letting it cool overnight and leaving you with the thrilling cliffhanger "So, does it work?" Today, I opened the bottle to investigate. Now read on...

Well, the good news is that the rosin sealant had not hardened at room temperature overnight, so I must assume that there is at least the required minimum amount of castor oil in the mix. It's certainly very thick as it is - thicker than shellac, certainly. I tested a tiny amount of the goo on a ballpoint's threads, and the results were encouraging... A picture says a thousand words, as the saying goes. Here's 7 minutes of pictures at 30 frames a second!

I'll finish writing this post, and apply some of the rosin based sealant to the threads of the Jinhao 321 shown in the video - I'll be sure to let you know how it works out in future posts.

"Rosin - Based" Fountain Pen Sealant

In this post, I'll be cooking up some "rosin based" fountain pen sealant. This mysterious goo is supposed to be a good alternative to shellac, in situations where a lower release temperature is preferred (such as the "I still can't get this apart, and if I apply any more heat it will melt in my hands" situation).

A block of rosin. How it glowses, my precious!

This is uncharted territory for me, I've never clapped eyes on "rosin based" sealant before. From various sources dotted about the web, I gather it's rosin dissolved in castor oil, heavy on the rosin. That's about as much as I know. Any right thinking amateur would reach for a credit card at this point, but to the best of my knowledge, there is no domestic UK source of premixed rosin based sealant. US based Main Street Pens springs to mind as an easy solution for American readers (or if you can think up a few more things to make international shipping worthwhile).

To begin with, I was dead against having to stock up on anything in bulk. If that had been necessary, I would honestly have preferred to just buy a handy 10ml vial, treading a big ugly carbon footprint from New York to Glasgow. I have exactly one drawer for pen-type tools - well, two, if you count the spark plug pliers (they've yet to meet any spark plug boots). There's no space for a litre of castor oil!

For £2.48 including postage, eBay seller Aina TM provided 11ml of "Organic Castor Oil BP" (amongst a jungle of unintelligible pharmaceutical properties, this variant seems to have lower acidity), while a 4cm diameter disc of 'Theodore' violin rosin cost £1.88 from DJMusic.

Rosin, check. Castor oil, check.

Preparing a glass storage vial
I had just the thing to store the potential sealant in - a 10ml glass vial, with an integrated application brush. This originally contained shellac, but what little that was left had long since gone off. An overnight soak in methylated spirits made light work of the shellac residue, and in turn, an overnight soak in soapy water made light work of the methylated spirits smell (I can't stand it).

Cleaning, and clean. A 10ml glass vial with screw-cap
and application brush.

I added an O-ring to help keep the vial air tight. Weirdly, there is a recess in the plastic cap ready for a rubber gasket to fit into place, but it didn't come with one installed.

Adding a cap gasket.
I'm much happier with a gasket in there, hopefully it will lend a really good seal. Let's move on to the rosin.

Breaking Down the Rosin Cake
This is a 4 centimetre diameter cake of "Theodore" violin rosin, bought specifically for its hypnotising amber radience, and the seller's mention of this variety's "slightly sticky interior texture offering plenty of grip". I found that rubbing the blade of a craft knife against the cake easily shaved the surface down to a fine powder, which could be poured into the glass vial.

"Theodore" violin rosin. Not quite double-rainbow
awesome, but still quite captivating.

As this step was bound to make a mess, I broke down the rosin in a piece of baking foil. This made a decent funnel too, for pouring the powdered rosin into the glass vial.

Breaking down the rosin, and filling up the vial.

Mixing In Castor Oil
The ratio of rosin to castor oil I was aiming for was 60-70 percent rosin, by volume. I came across that figure by way of a link in a great FountainPenBoard thread. That gem of a hint had been preserved in an abandoned, late '90s, Times-New-Roman-with-some-Hyperlinks type page still maintained by Syracuse University. It really kick-started this endeavour, so my thanks go out to a certain Vincent Fatica, who included an informative sojourn into the background and preparation of rosin sealant with his own recollections of making the stuff. Prior to reading this, the only other clue I had to work off was a mention of rosin based sealant being more viscous than shellac, which I had to hand as a gloopy frame of reference.

About to pour in some castor oil.
I'm no Archimedes I'm afraid; it was quite taxing on the old noggin to work out 70% of the vial's volume, allowing for the applicator brush's displacement, and leaving empty space for later adjustment to the mix. I decided to err on the side of caution, and aim for less than a full vial of sealant. That way, if I messed up the proportions, I could add rosin powder if the sealant turned out too runny, or more castor oil, if it was too viscous.

Anyhoo, I reached over to the bottle of castor oil, squeezed the integrated eyedropper, and started mixing a squirt into the rosin powder, using a large darning needle. I figured if I didn't get the rosin wet enough beforehand, heating it up would just melt it into a lump and I'd be back where I started.

To help the mixture heat evenly, I sat the vial in a hot bain-marie, over a medium flame. This had the unfortunate effect of fogging the camera lens in short order! The overturned foil pudding cup in the photos below was just a precaution against the vial tipping over in the bubbling water.

Heating the rosin/castor oil mix (I left the
darning needle in situ). Arrowed - checking texture.
I let the vial heat up for about 14 minutes, stirring occassionally. The darning needle came in handy as a sort of viscosity dipstick too! Here's a short clip to help illustrate the mixture's thickness.

After cooling, I noticed the sealant was still quite thick. If inverted, it takes quite a while longer than the shellac to shift from the top of the bottle to the bottom (as arrowed in the photograph below).

Arrowed - rosin based sealant,  slowly shifting
from the top to the bottom of the bottle.

Well, does it work?
I'll leave the vial alone overnight, and if it's still liquid enough tomorrow, try it out on some ballpoints before moving onto to fountain pens. I'll keep you posted!

Thanks, No Thanks!
Hugely helpful sources I used as a guide. Thanks all.

No Thanks! 
Blogger, I'm still having to paste break codes into photo captions by hand. It's no longer endearingly retro, you fellows!