Using metal epoxy putty to cast tools for obscure threaded fillers, seems to work.

[Flounder]

Yep - a servicable tool to unscrew obscure threaded fillers without gouging the threads. Having an exact match for the individual filler also helps minimise the clamping pressure required to turn it, which comes in particularly handy when dealing with non-metal, please-please-don't-deform-crack-or-thread-strip bosses.

This has taken me a while, experimenting safely with odds and sods (used up half the tube!) before using it on a pen - a nicely preserved, no name Japanese eyedropper with an ink shut off shaft. The shaft isn't watertight, and I want to ultimately change the seal. I've blogged a wordy version of this over a few posts, here's the useful info without all the exposition, extraneous stuff, &c.:


1. Coat the threads of the boss in red rubber grease
http://i773.photobucket.com/albums/yy19/flounder2009/Casting%20Disposable%20Fountain%20Pen%20Tools/th_EyedropperBossRedRubberGrease.jpg (http://s773.photobucket.com/user/flounder2009/media/Casting%20Disposable%20Fountain%20Pen%20Tools/EyedropperBossRedRubberGrease.jpg.html)

2. Wrap a single length of teflon round the boss
http://i773.photobucket.com/albums/yy19/flounder2009/Casting%20Disposable%20Fountain%20Pen%20Tools/th_EyedropperBossTeflonTape.jpg (http://s773.photobucket.com/user/flounder2009/media/Casting%20Disposable%20Fountain%20Pen%20Tools/EyedropperBossTeflonTape.jpg.html)

3. Mix up the metal epoxy, and within 2 minutes of mixing, apply it to the boss. After 5-7 minutes, it will be hard enough to also take an impression of plier teeth on the outside, if you're not using smooth pliers. After an hour, screw the newly formed C ring off the boss.
http://i773.photobucket.com/albums/yy19/flounder2009/Casting%20Disposable%20Fountain%20Pen%20Tools/th_EyedropperCRingToolB.jpg (http://s773.photobucket.com/user/flounder2009/media/Casting%20Disposable%20Fountain%20Pen%20Tools/EyedropperCRingToolB.jpg.html)

4. Unwrap the teflon, clean up the boss and tool with soapy water and a soft child's toothbrush, brushing along the threads rather than across. Rinse and dry.

5. Use the C ring tool as you would a conventional one.
http://i773.photobucket.com/albums/yy19/flounder2009/Casting%20Disposable%20Fountain%20Pen%20Tools/th_CastJapaneseEyedropperCRingToolInAction002.jpg (http://s773.photobucket.com/user/flounder2009/media/Casting%20Disposable%20Fountain%20Pen%20Tools/CastJapaneseEyedropperCRingToolInAction002.jpg.htm l)

6. Yay!
http://i773.photobucket.com/albums/yy19/flounder2009/Casting%20Disposable%20Fountain%20Pen%20Tools/th_CastJapaneseEyedropperCRingToolInAction010.jpg (http://s773.photobucket.com/user/flounder2009/media/Casting%20Disposable%20Fountain%20Pen%20Tools/CastJapaneseEyedropperCRingToolInAction010.jpg.htm l)

[Jeph]

That sounds so obvious after you explain it.
I have a pen begging for that right now!

What is the purpose of the red rubber grease, does the single wrap of teflon tape not always hold up or is it just extra insurance that the metal-set doesn't bond to the threads?
And what IS red rubber grease anyway?

Thanks Flounder

[Flounder]

Hi Jeph, the grease is there as an extra barrier to help stop the epoxy binding to the boss as it sets - it also helps keep the teflon in place as you wrap it round the threads. I don't know how critical it is, I just began the experiments presuming a single wrap of teflon alone would be too dicey.

I can say that the combo worked for all 10 C rings made (cast from metal satellite connector whatsits, a plastic football pump valve adaptor, and the pen itself).
Here's a youtube clip showing some of them.


https://www.youtube.com/watch?v=ULauTB1OQfM


I reckon the boss is made from BHR, so wanted to use a rubber safe grease. RRG is rubber safe, easier to wash off than silicone grease, and easier to see (being dyed red). Red rubber grease is made by a few different manufacturers, it's based on vegetable oils.



(this auto-logout thing is a a bit annoying! I just went to read some reviews!)

[Jeph]

Thanks for the explanation. I can sub glycerin then on the same premise. I have far too much of that laying around anyway.

[Flounder]

Hey, snap! I did use glycerine as a penetrating fluid inside the barrel (you can see it on the threads in step 5), I'm not sure it would stay where you want it in lieu of the rubber grease... maybe do a dry run first!

edit - I mean I used glycerine inside the barrel as I was unscrewing the boss to lubricate it as it was turning (the barrel was orientated nib-up), not during the C ring casting stage.

[vikramguliya]

Nice post and the explanation is simply superb