Shortcomings of Eyedropper filled vs. Piston

[PaulLeMay]

Sometimes I think too much.

 

I have read that eyedropper filled pens have a bad habit of spitting out a blob of ink, when the air in the pen is warmed by the hand.

I recall that pen manufacturers moved to sacs, levers etc. when they discovered this problem.

 

So how would my piston filled Pelikan M400 be any different? It doesn't seem any better insulated from hand warmth.

 

[wykpenguin]

I would guess it is more of a feed problem than a filling system problem. Otherwise the vacuum fillers would be squirting too.

[psfred]

Depends on the feed, how well the barrel insulates, how warm the pen is (carried in a pocket eyedroppers won't drip, sitting in a cold coffee mug and picked up to write they blot every time), and how much ink there is in the barrel.

 

Since my Parker 61s will blot if I don't warm them before using (my desk is quite cold in the winter), I'd bet a Vacumatic would as well.

 

Peter

[fjf]

I've read somewhere that is the volume. The pistons are limited to 1.5 ml and that volume of air doesn't expand enough to spit ink. The whole barrel is bigger and gives problems when it is almost empty, full od air expanding.

[PaulLeMay]

that makes sense. You must need a certain volume of air to expand in order to expel a certain sized drop of ink. Less volume = smaller expansion = smaller drop of ink.

 

[rlukcs]

Nowadays, the temperature in my home town is pretty low (5 deg. centigrade below 0). I have a piston filling pen in my bag. If there is only a last drop of ink left in the barrel (i.e. there's a lot of air in it), the pen ejects that last drop of ink when taken inside (I guess when I arive at my workplace, the temperature of the pen is around +5..10 deg., it warms up to above 20, and the air expands.

[RLTodd]

I have oft noted that after all the patents lapsed, neither Parker nor Sheaffer went to the screw piston filler used by Pelikan. Both spent considerable R&D money for the Aerometric, Snorkel, and cartridge/converter fill mechanisms.

 

[rlukcs]

I have oft noted that after all the patents lapsed, neither Parker nor Sheaffer went to the screw piston filler used by Pelikan. Both spent considerable R&D money for the Aerometric, Snorkel, and cartridge/converter fill mechanisms.

I think that the aerometric filler is cheaper to manufacture. With the Snorkel and cartridges, they wanted to achieve a different goal: make a pen that you could fill "wearing white gloves" (i.e. no wiping, no ink on your hands, etc.). The converter was a cheap solution to satisfy those customers who still wanted to use bottled ink. Besides, it's usually a cheap piston filling mechanism, which also helps to keep the manufacturing costs low. It usually does not last long, but it's cheap to replace. OTOH a good piston filler lasts decades, but it's quite expensive.

[Lloyd]

OTOH a good piston filler lasts decades, but it's quite expensive.

What about the Pelikan Go and the Reform 1745?

[RevAaron]

Self fillers weren't invented to deal with burps so much as convenience.

 

It's a matter of air volume. This is why a Pelikan M1000 only holds as much ink as an M200- it's by design, presumably. That said, I've never had problems in pens with superior ink supplies burping ink, like a vac fill OS Balance. *shrug*

[RLTodd]

.....

I think that the aerometric filler is cheaper to manufacture.

 

..........OTOH a good piston filler lasts decades, but it's quite expensive.

 

When there is some spare time available, one might wish to do a parts count on a '51" Aerometric or a Snorkel and compare same to a Pelikan piston filler. Then one may wish to consider the labor costs of assembling the three types of pens.

 

Also, there might be some consideration of German labor costs and how much of the Pelikan piston fillers are made by automated machinery.............

 

Then, of course, after reviewing the information available, each of us comes to our own conclusions.

 

As a further thought, the meaning of "expensive" and "cost" are quite different. Especially to cost accountants.

 

 

[badrsj]

This is why a Pelikan M1000 only holds as much ink as an M200- it's by design, presumably.

Just asking to confirm - I think you may have measured this? right?.

That would explain why my M1000 does not last longer than 2 days

[badrsj]

OK - now naming names - of pens that blurrped on my documents and earned terms of "non endearment"

ED Danitrio

Parker Vac

Dollar

Now realistically - this had more to do with the pens running on dry - i.e. mostly full of air - and not much ink left. I read somewhere this is well known bout the vacs.

Now pens that have "never" blurpped.

The piston filling / squeeze type - converters - sheaffers and parkers

None from piston filling Montblancs

In summation - it is the air volume - I agree.

 

 

[Ernst Bitterman]

I've never had a Vac hork on me, and in terms of volume, the rather slender Waterman 12 is willing to dribble at any time after half-empty. I think the primary drawback of an eyedropper is that breathless time after filling as the eyedropper is set aside and the section is returned to the top of that open mass of ink. Bad for the heart.

[demeter]

that makes sense. You must need a certain volume of air to expand in order to expel a certain sized drop of ink. Less volume = smaller expansion = smaller drop of ink.

 

 

Perhaps a dumb question...but wouldn't this problem be solved by uncapping the pen, holding it nib up, and letting everything warm up in your hand? It would seem a small amount of air would be pushed out the feed, no?

 

Andrew

[bgray]

I'm not convinced that eyedroppers really have burping problems due to hand temperature.

 

If an eyedropper burps on me, it's usually at the end of the fill.

 

I forget who posted it, but someone here gave a wonderful explanation as to why eyedroppers burp right at the end of the fill...I don't remember it right now.

 

I've never had burping problems with eyedroppers that have ink windows. When the ink gets low, I refill.

Edited February 23, 2009 by bgray