Sections for eyedroppers

[MikeinSC]

Would anyone be willing to share what size tap and die they like to use for making a section to be used in an eye dropper?

I'm using 10 x.75 and not feeling very satisfied with the fit and finish I'm getting. It may be me though.

Thanks.

 

[jalbert]

For me, it depends on the nib size I'm using. I generally use m10x.75 for #6, and M9x.75 for #5. I'm assuming you are concerned about fit and finish causing leakage issues? I haven't made many eyedroppers, but for piston fillers, which are kind of the same concept (a huge load of ink behind the nib), I fit an o-ring to the base of the section threads by turning a small groove in the threaded tenon. Additionally I turn a recess in the end of the barrel where the section threads in, so that the o-ring fits nicely when the section is screwed into the barrel, making a nice seal.

I know some people simply will use silicon grease to seal any gaps between the barrel and section, so my method may be overkill, however it doesn't take much effort to do, so I'd rather be safe then sorry! I hope this helps you. If my explanation didn't make sense, I'll try and find a picture of this on a pen I've made.

-John

P.S. Digging the Red Green quote Mike!

 

[duncsuss]

I generally use M9 x 0.75 for the section/barrel threads. This has worked for me with JoWo #6 nibs, Bock #5 nibs, and Esterbrook Renew-point units.

... for piston fillers, which are kind of the same concept (a huge load of ink behind the nib), I fit an o-ring to the base of the section threads by turning a small groove in the threaded tenon. Additionally I turn a recess in the end of the barrel where the section threads in, so that the o-ring fits nicely when the section is screwed into the barrel, making a nice seal.

I'd like to use o-rings but haven't found any suitable -- all the ones I look at seem to be way too fat. What type do you use? And where do you get them?

Thanks!

 

[jalbert]

I'll just go ahead and post this since I happened to find it on my phone.

 

[jalbert]

Duncan. I purchased mine on ebay.

1RHZ2 O Ring Buna N 4mm OD PK 100 | eBay

Thank the gods for the watch list saving your items, eh? I would never have remembered what size they were.
I find the 4mm size suitable for most applications, such as the seals on the head of the piston mechanism.

-John

 

[duncsuss]

Duncan. I purchased mine on ebay.

1RHZ2 O Ring Buna N 4mm OD PK 100 | eBay

Thank the gods for the watch list saving your items, eh? I would never have remembered what size they were.
I find the 4mm size suitable for most applications, such as the seals on the head of the piston mechanism.

-John

Thanks, John! You're right, the list of purchases is useful; Amazon is "even better" -- it remembers the stuff you looked at but didn't buy

Looks like I'll be making another one of those buys where the postage is twice the cost of the item :biggrin:

 

[jalbert]

I think I bought several more sizes to justify paying $5 shipping, but I really haven't used the others. I should have just bought some another boring bar or threading tool

 

[MikeinSC]

Thanks for the link to the o-rings. I ordered some of those. That will be easier than digging through old car parts boxes looking for fuel injector o-rings that are about the same size.

Duncsuss,
I too am using the Estie nibs for the eye droppers as they are my favorite nib. I'll try the 9x.75 to see if that gives me a better warm fuzzy.

Thanks y'all.

 

[jalbert]

I work in a factory, and looked through a huge organizer filled with o-rings and didn't find any suitable sizes. Autozone didn't have anything suitable either. I have a feeling this is a fairly specialty size. Anyway, I hope they do the trick for you Mike!