Cleaning Eyepieces (internal)

I recently purchased one of the new Speers-waler 82* eyepieces (7.5mm), and like many other people have reported there appears to be a sizable speck of dust on one of the internal elements. I have asked the seller what I should do about this (he hasn't responded yet), but my preference would be to just take the thing apart and clean it myself and not worry about shipping it and/or getting another contaminated eyepiece. I would consider myself handy enough to undertake such a task, but I have a few specific questions:
1) Is this a REALLY bad idea and I should just forget the idea?
2) What measures should I take to keep the glass and interior clean?
3) What measures should I take to make sure I don't end up with a pile of glass and no idea what order to put the lenses back in? (I believe there are 8 elements)
4) Has anyone taken apart this eyepiece (or similar) and has advice specific to this eyepiece?
5) Is there anything else I should know/consider?

Thanks,
Jeremy

Jeremy,

If you have good dexterity and are good at cleaning fingerprints and smudges off lenses to your satisfaction, then taking eyepieces apart is not that daunting of a task. I did the same thing with a Speers-Waler Zoom--essentially completely disassembled it to get out all the dust.

Ease of disassembly depends on the eyepiece design--spacers and retaining rings, etc. Some lens configurations simply drop out in a single stack once a lower retaining ring is removed (Widescan II, for example). Others have internal rings holding things in place. These are harder to disassemble and reassemble. Sometimes you can only get an eyepiece partially disassembled before it becomes too difficult, but partial disassembly is sometimes enough to get to the stubborn debris to blow it out with a bulb blower or remove it with alcohol and a Q-tip.

Something that might help with some eyepieces is some kind of tool that can pull a lens carefully up and out of the barrel without having to turn the eyepiece over and let the lenses drop out, like a small suction cup--I assume these are available (and probably from Edmund Scientific Optics Division). Or you can hold a lens in place with the tip of your finger, turn the barrel over and gently drop it out if you must, though you must clean it properly (Q-tip and 99% isopropyl alcohol is what I'd use).

Another useful tool is a spanner wrench to grip the two opposing notches in a retaining ring. A tiny screwdriver often works, but sometimes the ring won't budge with a one point tool. Finally, don't even think about it unless you have a squeeze bulb blower to blow off any dust that might settle, or you could end up with more than you started with. I've removed internal dust from a 35mm Panoptic, edge-blackened the lenses of three Widescan II's, and several other eyepieces and binoculars. Most recently I disassembled an Astro-Physics 8x50 illuminated finder that had let dust in through an unplugged illuminator hole. Turned out perfect. I have never had a mishap and have always ended up with better than I started with, so I suppose it can be done, but I've been ready each time to pay for a repair or replacement if I did as you fear: ending up with a pile of glass and no idea which way or order to reassemble it. That is just a risk you take. It helps to remember it's only money. You'll eventually get more ;^).

Lee

I haven't had a chance to try this EP out yet, so I don't know to what extent the particle will affect the views. In daylight, my clearest views of the particle are when my eye is about two inches from the lens, although it is still very obvious when I hold my eye at a more usual viewing distance.

I've tried tapping (and banging) the eyepiece against the palm of my hand, and this doesn't move the particle.

Lee, do you remember if the SW zoom was a easy or difficult to work with? I'm not sure how indicative this will be of my eyepiece, because I assume zooms are more difficult to work wi in general.

I won't do anything till I hear back from the seller, but right now I'm leaning toward a middle ground. I can unscrew the eyepiece from either end, and since a quarter turn at either end doesn't change the position of the particle, I can conclude that any lenses held in the endpieces are clean. Each endpiece holds at least one lens, (the bottom end looks like it holds more) so this rules out almost half the surfaces. I think I might just unscrew each end and chech the most accessible surfaces, and if they are clean, put it back together and forget about it.

Looks like a happy ending here. I unscrewed the barlow and gave it a blast of air and the particle moved. However, it was replaced by a new one. After checking that the lenses were secure, I inverted the EP and gave a couple more blasts of air, and everything is nice and clear now.

Thanks for the help everyone.

Jeremy