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Re: Best practices and construction for dust covers
Posted: Sat Oct 23, 2021 8:23 pm
by Greg Howald
Ok. I cheated. I went to the housewares department, bought twelve matching satin pillow cases and was satisfied.
But then. That's me.
Re: Best practices and construction for dust covers
Posted: Sat Oct 23, 2021 8:45 pm
by farnsy
Anyone have thoughts on why Zeiss recommends 2 plastic bags and a cover?
Re: Best practices and construction for dust covers
Posted: Sat Oct 23, 2021 11:37 pm
by Lomonaut
Zeiss must
really hate dust
How about a metal dome with leather grip, like for the old Lomo MBU-4. I'm not even showing the bottom part... all of this just for an entry level student microscope (40+ years ago)!
Re: Best practices and construction for dust covers
Posted: Sun Oct 24, 2021 1:04 am
by microcosmos
I love that metal sarcophagus. Just like many other things in the world, dust covers have progressed from solid metal to flimsy plastic. From silverware to disposable cutlery.
Re: Best practices and construction for dust covers
Posted: Sun Oct 24, 2021 1:18 am
by microcosmos
Hobbyst46 wrote: ↑Sat Oct 23, 2021 8:04 pm
I think that, if indeed condensation is likely (for any climatic/environmental reason), keeping the microscopes warm is the most practical and economical way. Less nuisance than dehumidifiers of any sort. HEPA filters are an overkill, IMHO.
I can't prove it definitively but my impression is that in tropical countries, keeping the microscope warm may not work well enough to keep fungus off, as the humidity is very high and in order to have a significant effect the microscope may have to be heated considerably warmer than the already warm air temperature, which means it almost has to be hot to the touch! (Of course this doesn't apply if the microscope is in an air-conditioned room - mine isn't.)
So under my circumstances, I feel safer removing the water directly. It is a nuisance as you say but not unbearable - yet.
Re: Best practices and construction for dust covers
Posted: Sun Oct 24, 2021 5:27 am
by BramHuntingNematodes
the big problem is the microscope getting cold during the night then staying cold as the air warms up, inviting condensation. If you heat it, then, you will want to keep it about as hot as the daytime temperature so that when a gust of air during the day sneaks in it doesn't cause problems.
Re: Best practices and construction for dust covers
Posted: Sun Oct 24, 2021 7:02 pm
by MicroBob
My impression of the development of fungus is that no real condensation has to take place, it sems to be enough when the instrument is stored in a slighly damp place for long enough. Otherwise I wouldn't have found fungus on inner lenses of camera objectives and binoculars as often as I have. But this will probobly depend on the actual conditions. Fungus growth at 10°C will not be the same as at 20 or 30°C. So the heating might work nice in a cold environment and less so in a warm one.
Re: Best practices and construction for dust covers
Posted: Sat Aug 05, 2023 12:22 pm
by blekenbleu
microcosmos wrote: ↑Sun Oct 24, 2021 1:04 am
Just like many other things in the world, dust covers have progressed from solid metal to flimsy plastic.
translucent PVC microscope dust covers, 7 sizes US$2.95 ea
https://www.aliexpress.us/item/2255800489788261.html
Re: Best practices and construction for dust covers
Posted: Sat Aug 05, 2023 6:14 pm
by PeteM
There's a notion that if you can smell the plastic, it's outgassing, and you don't want to use much of it near either humans or sensitive optical instruments:
https://www.directplastics.co.uk/news/w ... d-you-care
Personally, I avoid the PVC covers often supplied with older microscopes. Here's PVC's reputation twenty years ago - past the era of Olympus BH2 and early BX, Nikon 'phot and early Eclipse scopes etc:
https://www.greenpeace.org/usa/wp-conte ... astic.html
That said, the suggestions I've seen that polyethylene is a bit better may be due as much to a lack of research as real superiority. For now, at least, 2 and 4 mil polyethylene bags are my choice. For a few treasured microscopes, a proper wood-metal-glass case would be dandy.
Re: Best practices and construction for dust covers
Posted: Sun Aug 06, 2023 6:20 am
by Hobbyst46
PeteM wrote: ↑Sat Aug 05, 2023 6:14 pm
There's a notion that if you can smell the plastic, it's outgassing, and you don't want to use much of it near either humans or sensitive optical instruments:
https://www.directplastics.co.uk/news/w ... d-you-care
Personally, I avoid the PVC covers often supplied with older microscopes. Here's PVC's reputation twenty years ago - past the era of Olympus BH2 and early BX, Nikon 'phot and early Eclipse scopes etc:
https://www.greenpeace.org/usa/wp-conte ... astic.html
That said, the suggestions I've seen that polyethylene is a bit better may be due as much to a lack of research as real superiority. For now, at least, 2 and 4 mil polyethylene bags are my choice. For a few treasured microscopes, a proper wood-metal-glass case would be dandy.
PVC itself is solid. To make flexible PVC such as used for dust covers, various additives are mixed with it. These possibly give off the unpleasant smell (which fades with time).
Polyethylene is certainly better from this point of view.
Irrespective of long range damage and toxicity to the planet, which depends on many factors and not just the chemical composition.
But then. That's me.