13 replies to this topic

[TicoWiko]

As you can see from the image below, I've recently started storing my EPs in a foam filled protective case.

 

 

 

 

On the bottom row, I've included a fair number of desiccant silica gel bags to avoid trapping moisture in the case and turning it into a moldy death trap for all my glass. They change color when they're saturated and need changing, and the case itself has a handy little knob I can tighten to make it airtight when it's closed, so I believe I can reliably keep my case dry in the long run. My question is about the EPs themselves (and the same goes for the Paracorr). Should I store them with the lens caps off ? I can't tell if I should leave the caps on for better security, or if leaving them on will trap moisture that the desiccant bags can't get to. I might be overthinking it, but especially since it's not uncommon for the cold glass to end up with a little dew on it that I might not notice, I wanted to make sure I got this right. It'd be a shame to have built a home for all my glass then have the true moldy death trap be something as benign as the lens caps.

 

Any other proper storage tips are welcome, as well as specific criticisms of how I'm storing mine. Feel free to call me an idiot (with helpful explanations) if you see anything wrong with how I'm storing them.

 

Clear skies

[Polyphemos]

I’d leave the lens caps on to protect against dust from deteriorating foam. The caps aren’t 100% airtight and over time the relative humidity will be the same on either side of the caps.

[Brent Campbell]

I don’t use desiccant for a couple of reasons.  1) It’s poisonous to pets.  2) Eventually it “ fills up” and needs to be replaced.  3) Nothing beats air circulation with warm dry air.

 

You desiccant may not be all that effective because when your case it closed there is no air circulation.

 

 

What I do instead.   At the end of the night I take my eyepiece case into my warm  house, open it up, and go to bed.  Sometime the next morning everything is dry and I can close the eyepiece case up again.  I also do this with scopes and mounts.  Typically I take them inside the house the next morning ( due to size and not wanting to wake my wife up) but I use the same process, open the case and let them gradually air dry in the warm  house for a few hours then close them up again.  I have never had any issues. 

[Polyphemos]

Pets have no place in an eyepiece case, some kinds of silica can be dried in a microwave oven and restored to as new condition, warm dry air isn’t available year round to everyone but the correct silica gel packs and a reasonably airtight case are.

 

It’s untrue that there is no air circulation in a closed case. There are more than enough convection currents in any normal closed case to ensure even distribution of gasses and moisture within the system.

 

Don’t use those little gel packs. I think they’re more for show than for controlling moisture. Use these instead which come in multiple sizes and which are renewable in a microwave. Amazon carries them.

 

 

I weigh them out of their sealed container so that I can monitor moisture accumulation within them over time, and so that I know when all of the moisture has been removed by microwaving.

Attached Thumbnails

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Edited by Polyphemos, 02 February 2025 - 02:47 PM.

[TicoWiko]

Pets have no place in an eyepiece case, some kinds of silica can be dried in a microwave oven and restored to as new condition, warm dry air isn’t available year round to everyone but the correct silica gel packs and a reasonably airtight case are.

It’s untrue that there is no air circulation in a closed case. There are more than enough convection currents in any normal closed case to ensure even distribution of gasses and moisture within the system.

Don’t use those little gel packs. I think they’re more for show than for controlling moisture. Use these instead which come in multiple sizes and which are renewable in a microwave. Amazon carries them.

IMG_3312.jpeg

I weigh them out of their sealed container so that I can monitor moisture accumulation within them over time, and so that I know when all of the moisture has been removed by microwaving.

That is in fact the exact brand I got ! I simply could not find them in a bigger size, so I just use a bunch of the smaller packets. They are reheatable and color coded to let you know when that's needed.

As for the question of air currents, you're absolutely right. Air is very much an ideal gas so the only thing that matters to the distribution of one of the gases in your air mixture is the partial pressure of that gas. If one corner gets dryer, the moisture from the rest of the case will move in near instantly and equalize things. No air currents are needed for the desiccant to act on all the air inside the case. And if as you say the lens caps aren't actually air tight, then that applies there too.

Good point about foam bits, hadn't thought of that. Helps to settle the question

[TicoWiko]

And of course as soon as I say that I go online and find the same size as you haha. Should make for a cleaner case.

Clear skies

[TicoWiko]

I don’t use desiccant for a couple of reasons. 1) It’s poisonous to pets. 2) Eventually it “ fills up” and needs to be replaced. 3) Nothing beats air circulation with warm dry air.

You desiccant may not be all that effective because when your case it closed there is no air circulation.


What I do instead. At the end of the night I take my eyepiece case into my warm house, open it up, and go to bed. Sometime the next morning everything is dry and I can close the eyepiece case up again. I also do this with scopes and mounts. Typically I take them inside the house the next morning ( due to size and not wanting to wake my wife up) but I use the same process, open the case and let them gradually air dry in the warm house for a few hours then close them up again. I have never had any issues.

I'm not too worried about my pets eating this. I keep my scope stuff well organized and inaccessible. I agree ideally I'd store this stuff somewhere drier and warmer than my garage, but this hobby takes up a fair amount of space so garage it is. And air currents are not needed for desiccant to be effective, see my reply above.

The garage storage is why I want to really get this right. The upside is it keeps my scope at the right temperature at all times. The downside is having to get storage care right.

Clear skies

[CrazyPanda]

or if leaving them on will trap moisture that the desiccant bags can't get to.

 

 

This is a great question, and it depends on the design of the cap.

 

In my original case, I kept a 100g silica gel pack in it and took all precautions to keep it dry.

 

But one day after the EPs had been in storage for a month (fresh silica gel pack) due to bad weather, I took the cap off my 17mm Explore Scientific 92 only to find fungus had grown on the eye lens.

 

The interior of the case was dry - all the other eyepieces were fine, it was just the ES92.

 

Turns out that the ES92 eye guard and cap design creates a PERFECT rubber seal. Whatever the relative humidity of the air trapped under the cap is, is how it will remain. The silica gel won't help.

 

However, many eyepiece caps offer ridges that create small gaps that allow the lenses to breathe. These usually are fine.

 

But, the stock caps of the Takahashi TPLs and TOEs create a solid seal around the eye guards. I needed to remove the eye guards to buy back some eye relief, and I 3D printed new caps that take air flow into consideration:

 

 

 

Note the little vents? The cap does not sit flat on top of the eyepiece, so there is ample air flow.

 

So should you keep the caps on or off?

 

You should definitely keep them ON for three reasons:

 

1. Avoids accidentally touching the glass with your finger when retrieving an eyepiece

2. That foam can break down and can deposit gunk onto the lens overtime

3. If the foam makes contact with the lens, you'd be constantly rubbing the coating with the foam every time you take the eyepiece in and out. I can see it dulling the coating over time.

 

That being said, I think you should absolutely drill some vent holes in the caps if you find that they are sealing tight against the rubber or the bottom of the eyepiece. "Dust caps" are less about preventing dust (your eyepieces are going to get dusty during use anyway), and more about preventing the things I mentioned above. But you do want to ensure they allow for air flow.

 

 

 

Any other proper storage tips are welcome, as well as specific criticisms of how I'm storing mine. Feel free to call me an idiot (with helpful explanations) if you see anything wrong with how I'm storing them.

 

I would replace the open-cell PU foam with closed-cell PE foam (like Kaizen foam). The open cell stuff absorbs and holds onto moisture like a sponge. The closed cell stuff does not.

 

 

 

You desiccant may not be all that effective because when your case it closed there is no air circulation.

 

You don't actually need air circulation for desiccant to work. Moisture, like heat, will seek equilibrium in a closed environment. The desiccant pack pulls in moisture from the air directly adjacent to it. Now that air is low in moisture while the air next to that is higher in moisture, so moisture will diffuse from high to low, and so on and so forth. Eventually the whole case will be dry, and will be below the fungal growth level of RH within a few hours. 

 

All of my cases seal and are IP67 waterproof. During the summer, relative humidity is about 70-80% for days on end.

 

If I put a fresh silica gel pack in the case along with a hygrometer and wait about 12 hours, the case will be around 40% humidity. If I wait a few days, it will eventually drop down to ~15% humidity which is the lowest my hygrometer will even measure, meaning the actual RH in the case is probably single digits. No air circulation required. That said, I would be willing to bet that even minor temperature fluctuations creates thermal currents that naturally circulates the air in the case anyway.

 

Because the cases seal, it will stay that way indefinitely. I don't have to worry about the silica gel pack saturating and ceasing to work, because the case is non-permeable. I can throw the pack in, and keep the case closed for years on end if I want to.

During regular use, if I take the time to put the pack in a plastic baggie, I can make it last a lot longer. If I'm lazy and let it be exposed to outdoor air, it will saturate after just a couple of sessions. That's ok, I can just put a fresh one in and recharge that one.

Edited by CrazyPanda, 02 February 2025 - 03:49 PM.

[Brent Campbell]

Pets have no place in an eyepiece case, some kinds of silica can be dried in a microwave oven and restored to as new condition, warm dry air isn’t available year round to everyone but the correct silica gel packs and a reasonably airtight case are.

 

 

Pets can get into anything. The typical dog has the mental capacity of a 4-5 year old child, and lord knows how many children swallow something poisonous.   

[Polyphemos]

Pets can get into anything. The typical dog has the mental capacity of a 4-5 year old child, and lord knows how many children swallow something poisonous.   

You can extend reasonable caution to unreasonable lengths.

 

What do you do about cleaners, laundry detergents, and disinfectants? How about automotive products like engine oil, coolant, and various other lubricants and solvents? Then there’s beer, wine, and bourbon.

 

Is everything potentially hazardous banned from your property because Rover might pull the cork out of your Petite Sirah, pop a cold one too many, or flip the clasps on your eyepiece case to chomp on some silica gel packs nestled inside, or do you do what most of us do and take reasonable and prudent precautions to protect both our loved ones and our gear?

[Polyphemos]

This is a great question, and it depends on the design of the cap.

 

In my original case, I kept a 100g silica gel pack in it and took all precautions to keep it dry.

 

But one day after the EPs had been in storage for a month (fresh silica gel pack) due to bad weather, I took the cap off my 17mm Explore Scientific 92 only to find fungus had grown on the eye lens.

 

The interior of the case was dry - all the other eyepieces were fine, it was just the ES92.

 

Turns out that the ES92 eye guard and cap design creates a PERFECT rubber seal. Whatever the relative humidity of the air trapped under the cap is, is how it will remain. The silica gel won't help.

 

However, many eyepiece caps offer ridges that create small gaps that allow the lenses to breathe. These usually are fine.

 

But, the stock caps of the Takahashi TPLs and TOEs create a solid seal around the eye guards. I needed to remove the eye guards to buy back some eye relief, and I 3D printed new caps that take air flow into consideration:

 

tpl-dust-caps-3D.JPG

 

tpl-dust-caps-1.jpg

 

Note the little vents? The cap does not sit flat on top of the eyepiece, so there is ample air flow.

 

So should you keep the caps on or off?

 

You should definitely keep them ON for three reasons:

 

1. Avoids accidentally touching the glass with your finger when retrieving an eyepiece

2. That foam can break down and can deposit gunk onto the lens overtime

3. If the foam makes contact with the lens, you'd be constantly rubbing the coating with the foam every time you take the eyepiece in and out. I can see it dulling the coating over time.

 

That being said, I think you should absolutely drill some vent holes in the caps if you find that they are sealing tight against the rubber or the bottom of the eyepiece. "Dust caps" are less about preventing dust (your eyepieces are going to get dusty during use anyway), and more about preventing the things I mentioned above. But you do want to ensure they allow for air flow.

 

 

 

 

I would replace the open-cell PU foam with closed-cell PE foam (like Kaizen foam). The open cell stuff absorbs and holds onto moisture like a sponge. The closed cell stuff does not.

 

 

 

 

You don't actually need air circulation for desiccant to work. Moisture, like heat, will seek equilibrium in a closed environment. The desiccant pack pulls in moisture from the air directly adjacent to it. Now that air is low in moisture while the air next to that is higher in moisture, so moisture will diffuse from high to low, and so on and so forth. Eventually the whole case will be dry, and will be below the fungal growth level of RH within a few hours. 

 

All of my cases seal and are IP67 waterproof. During the summer, relative humidity is about 70-80% for days on end.

 

If I put a fresh silica gel pack in the case along with a hygrometer and wait about 12 hours, the case will be around 40% humidity. If I wait a few days, it will eventually drop down to ~15% humidity which is the lowest my hygrometer will even measure, meaning the actual RH in the case is probably single digits. No air circulation required. That said, I would be willing to bet that even minor temperature fluctuations creates thermal currents that naturally circulates the air in the case anyway.

 

Because the cases seal, it will stay that way indefinitely. I don't have to worry about the silica gel pack saturating and ceasing to work, because the case is non-permeable. I can throw the pack in, and keep the case closed for years on end if I want to.

During regular use, if I take the time to put the pack in a plastic baggie, I can make it last a lot longer. If I'm lazy and let it be exposed to outdoor air, it will saturate after just a couple of sessions. That's ok, I can just put a fresh one in and recharge that one.

Good post and well worth heeding if there’s any question concerning your eye caps being completely impermeable.

[TicoWiko]

Rover might pull the cork out of your Petite Sirah, pop a cold one too many, or flip the clasps on your eyepiece case to chomp on some silica gel packs nestled inside

Now there's an image 😂

[TicoWiko]

This is a great question, and it depends on the design of the cap.

In my original case, I kept a 100g silica gel pack in it and took all precautions to keep it dry.

But one day after the EPs had been in storage for a month (fresh silica gel pack) due to bad weather, I took the cap off my 17mm Explore Scientific 92 only to find fungus had grown on the eye lens.

The interior of the case was dry - all the other eyepieces were fine, it was just the ES92.

Turns out that the ES92 eye guard and cap design creates a PERFECT rubber seal. Whatever the relative humidity of the air trapped under the cap is, is how it will remain. The silica gel won't help.

However, many eyepiece caps offer ridges that create small gaps that allow the lenses to breathe. These usually are fine.

But, the stock caps of the Takahashi TPLs and TOEs create a solid seal around the eye guards. I needed to remove the eye guards to buy back some eye relief, and I 3D printed new caps that take air flow into consideration:

tpl-dust-caps-3D.JPG

tpl-dust-caps-1.jpg

Note the little vents? The cap does not sit flat on top of the eyepiece, so there is ample air flow.

So should you keep the caps on or off?

You should definitely keep them ON for three reasons:

1. Avoids accidentally touching the glass with your finger when retrieving an eyepiece
2. That foam can break down and can deposit gunk onto the lens overtime
3. If the foam makes contact with the lens, you'd be constantly rubbing the coating with the foam every time you take the eyepiece in and out. I can see it dulling the coating over time.

That being said, I think you should absolutely drill some vent holes in the caps if you find that they are sealing tight against the rubber or the bottom of the eyepiece. "Dust caps" are less about preventing dust (your eyepieces are going to get dusty during use anyway), and more about preventing the things I mentioned above. But you do want to ensure they allow for air flow.




I would replace the open-cell PU foam with closed-cell PE foam (like Kaizen foam). The open cell stuff absorbs and holds onto moisture like a sponge. The closed cell stuff does not.




You don't actually need air circulation for desiccant to work. Moisture, like heat, will seek equilibrium in a closed environment. The desiccant pack pulls in moisture from the air directly adjacent to it. Now that air is low in moisture while the air next to that is higher in moisture, so moisture will diffuse from high to low, and so on and so forth. Eventually the whole case will be dry, and will be below the fungal growth level of RH within a few hours.

All of my cases seal and are IP67 waterproof. During the summer, relative humidity is about 70-80% for days on end.

If I put a fresh silica gel pack in the case along with a hygrometer and wait about 12 hours, the case will be around 40% humidity. If I wait a few days, it will eventually drop down to ~15% humidity which is the lowest my hygrometer will even measure, meaning the actual RH in the case is probably single digits. No air circulation required. That said, I would be willing to bet that even minor temperature fluctuations creates thermal currents that naturally circulates the air in the case anyway.

Because the cases seal, it will stay that way indefinitely. I don't have to worry about the silica gel pack saturating and ceasing to work, because the case is non-permeable. I can throw the pack in, and keep the case closed for years on end if I want to.

During regular use, if I take the time to put the pack in a plastic baggie, I can make it last a lot longer. If I'm lazy and let it be exposed to outdoor air, it will saturate after just a couple of sessions. That's ok, I can just put a fresh one in and recharge that one.

Thank you for the very thorough answer ! And for making me feel less dumb about my question.

I'll look into both of those things ASAP. Maybe cut some ridges on the caps if needed, and changing out the foam that does indeed look very spongey.

Clear skies

[Polyphemos]

Thank you for the very thorough answer ! And for making me feel less dumb about my question.

I'll look into both of those things ASAP. Maybe cut some ridges on the caps if needed, and changing out the foam that does indeed look very spongey.

Clear skies

Your question wasn’t dumb and I’m sure everyone here learned something from the exchange.