So many postings: Truth and myth about humidity levels

[Achim Reh]

During the past weeks, I have read countless post about the humidity level in dry boxes, and I am myself also not sure anymore what is the truth, what is imagination, an what is a typical urban myth. So, I call up the head of material research from one of my clients, to have chat with him. This company ( do not want to post the name here) , is a world market leader in silicones and elastomers, as well as high tech lubricants.

I asked some very simple questions, and would like to share the answers here.
Question
1) Does the humidity effect the degeneration of rubber ?
Answer
Yes, but it has a rather small impact. Also, it depends on the type of rubber material. Some rubbers degenerate faster in high humidity, some in low humidity.
Question
2) So, what has a high impact on rubber degeneration ?
Answer
4 major factors
1) High temperature. The higher the temperature is, the faster the rubber degenerates. This effect is exponential, means it gets much stronger with higher temperatures. The starting point is about 18 degrees celsius. ( rubber can also be stressed at extreme low sub zero temperatures, but that is a different effect)
2) UV light. Almost all rubber materials, synthetic and natural, age much faster under UV light.
3) Mechanical stress. Constant movement or tension leads to a faster degeneration of rubber materials
4) Oxygen. The higher the oxygen content in the environment is , the faster is the degeneration.

Question
3) Do lubricants dry out in low humidity
Answer
No. Modern synthetic technical lubricants ( different form medical lubricants) are not water based, the ingredients are not water-soluble. The level of humidity has hardly any impact on the evaporation of the volatile ingredients.
Question
So,what has an impact on lubricants.
Temperature has a rather big impact on lubricants (but most modern lubricants are not effected by room temperature), and so has dirt and dust. Contamination (Microscopic dust particles) probably has the biggest impact on technical lubricants which are used in room temperature.

 

[David Kwok]

Fantastic and good information.

 

[Prince Photogenic]

Thanks for sharing this, Achim..

 

[Octarine]

So what are the conclusions now?
1) Humidity in dry cabinets can be lower than the commonly recommended range of 45-50%.
2) Get sunblock lotion for your camera grip.

 

[Achim Reh]

Well, I posted this, because we had 2 earlier discussion2 on light in dry boxes and humidity levels. I also had experience with fungus inside a well working dry cabinet myself .
On the other hand, I recently went back to my old home in germany, and discovered some antique cameras, that where stored in a basement in a simple carton box for decades.
The basement has around 60 to 70% humidity, but only a temperature between 10 and 16 degrees celsius whole year around.
The 2 cameras ( age between 60 and 75 years !!!) where in perfect condition, no fungus, no peeled of rubber parts, mechanical shutters where working flawless. And I was really surprised by this.

My personal conclusion is

keep the humidity level low , the recommended 45% to 50% is fine ( also different manufacturers sometimes recommend 40%) , and it also doesn't hurt the camera or lens, if the humidity is 20% or 30%. I probably keep it between 30% ad 40% .

Keep the camera equipment away form EXCESSIVE UV light, ( that does not mean, don't take your equipment out for shooting) .But, non UV lights ( for example LED lights, which have zero UV emission) will prevent fungus from growing, and will not harm your equipment in any way. I put some led's in my dry cabinet.

Keep your camera stuff, cabinet, bags and so on CLEAN. I clean the dust in my bags and dry cabinets on a regular bases.

Unfortunately, there is no practical solution in singapore for the temperature issue, and there is no dry cabinet that cools down to 18 degrees ( this might also gives a condensing problem each time you take the equipment out ). Nothing we can do there.

 

[Octarine]

Unfortunately, there is no practical solution in singapore for the temperature issue, and there is no dry cabinet that cools down to 18 degrees ( this might also gives a condensing problem each time you take the equipment out ). Nothing we can do there.

A DIY solution could be to 'cross-breed' a wine cooler and a dry cabinet. But that could bring up the topic of condensation when taking out the gear from the cabinet.

 

[timwongek]

Hmm....does this mean a simple tupperware/dry box with thirsty hippo will do?

 

[TWmilkteaTW]

Interesting info. Thanks for share.

 

[Valkarian]

Hmm....does this mean a simple tupperware/dry box with thirsty hippo will do?

Haha! Well yes, but understand that thirsty hippo is meant for fabric and may not be the setting you want for your lenses. I don't actually know what it will do lol! Why not just get a bottle of silica gel? Any airtight box will do Tho IMO.

 

[daredevil123]

My dad has a dry cab set at 30% for decades. No fungus, no cracked or peeling rubber, no discoloration, no dried up lubricants. Then again, they don't make things like they used to, and stuff in that dry cab are all old cameras.