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#1 avigo

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Posted 02 May 2018 - 06:41 AM

Hi Guys,

The humidity in my apartment has been around 50%.

As far as collectibles go, is this too humid? I know 40/45% is ideal for comfort but as far as damaging things, should I get a heavy duty dehumidifier?

I have damprids in my apartment but they don't drop the humidity at all.

 

Somewhat related question, are there any high end, very accurate hygrometers out there? I just use one of the top rated ones on Amazon but it doesn't seem super accurate.

Thanks!
 



#2 General Apathy

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Posted 02 May 2018 - 07:45 AM

Hi Guys,
The humidity in my apartment has been around 50%.
As far as collectibles go, is this too humid? I know 40/45% is ideal for comfort but as far as damaging things, should I get a heavy duty dehumidifier?
I have damprids in my apartment but they don't drop the humidity at all.
 
Somewhat related question, are there any high end, very accurate hygrometers out there? I just use one of the top rated ones on Amazon but it doesn't seem super accurate.
Thanks!
 

.
Hi Avigo, how very weird, I had several of these 1943 dated USMC Heatabs, and sadly due to humidity I lost three of them, the tabs inside absorbed the humidity and dissolving the tabs the tubes then fell apart as well from the moisture.

literally just five minutes ago before finding your post I wrapped my last perfect one in food-wrap to preserve it and the tabs inside, I have had previous success doing this with other GI items, soap, chocolate bars, cigarette packs, and other items susceptible to moisture.

Being a round tube it is more difficult to seal the ends neatly, much easier on square items.

Also amused by your Avatar photo, I have the same style watch in my collection, but no-where as clean as your example......... Nice piece.

Good luck with your quest for protecting your collection.

Lewis.

. image.jpg

#3 avigo

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Posted 02 May 2018 - 07:51 AM

.
Hi Avigo, how very weird, I had several of these 1943 dated USMC Heatabs, and sadly due to humidity I lost three of them, the tabs inside absorbed the humidity and dissolving the tabs the tubes then fell apart as well from the moisture.

literally just five minutes ago before finding your post I wrapped my last perfect one in food-wrap to preserve it and the tabs inside, I have had previous success doing this with other GI items, soap, chocolate bars, cigarette packs, and other items susceptible to moisture.

Being a round tube it is more difficult to seal the ends neatly, much easier on square items.

Also amused by your Avatar photo, I have the same style watch in my collection, but no-where as clean as your example......... Nice piece.

Good luck with your quest for protecting your collection.

Lewis.

. attachicon.gifimage.jpg

 

I'm sorry to hear that!

What was the humidity % of the area those items were stored in?

 

Yeah, I love those Elgin watches!



#4 Blacksmith

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Posted 02 May 2018 - 09:49 AM

I would contend that there is no single right RH%, as it all depends on what is in the room. While drier may be better for some items, like steel, too dry can be harmful for other materials - like rubber, leather, etc.

I’ve known guys who dried the air out entirely, to protect knives, and turn the leather sheaths into a craggy mess. You can do the same with firearms. Bone dry to keep the metal from oxidizing, and crack stocks in doing so.

Maybe the answer is that you have different zones for different items. Generally, I don’t worry about it.

#5 avigo

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Posted 02 May 2018 - 10:54 AM

I would contend that there is no single right RH%, as it all depends on what is in the room. While drier may be better for some items, like steel, too dry can be harmful for other materials - like rubber, leather, etc.

I’ve known guys who dried the air out entirely, to protect knives, and turn the leather sheaths into a craggy mess. You can do the same with firearms. Bone dry to keep the metal from oxidizing, and crack stocks in doing so.

Maybe the answer is that you have different zones for different items. Generally, I don’t worry about it.

 

Makes sense. but I really can't have zoned off areas.

 

What's a good "middle ground"

 

Is 50% (in general terms) too humid?

 

I have a lot of wood and leather that I also don't want to dry out. So I'm guessing between 45 and 60% is probably where I should be. Does that make sense?



#6 Blacksmith

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Posted 02 May 2018 - 11:26 AM

Ooooh, Im not qualified to say really - other than 40% seems to be a number that I hear folks use a lot. I know an environmental engineer, that quotes that number as being good general guidance. Dry enough that stuff wont grow, like mold, and not arrid enough to completely dessicate organic materials (wood, leather, and the like).

Again, I would seek expert advice, maybe from a qualified museum curator (Im thinking Smithsonian). Theres maybe even a guild where those folks gather, or even literature, that could be a good source.

I also vaguely recall past forum discussions on this.

I think another important consideration is consistency. So, frequent fluctuation between high and low humidity is a factor as well. A luthier would likely have good insight, as would anyone making musical instruments of mixed materials.

 
Makes sense. but I really can't have zoned off areas.
 
What's a good "middle ground"
 
Is 50% (in general terms) too humid?
 
I have a lot of wood and leather that I also don't want to dry out. So I'm guessing between 45 and 60% is probably where I should be. Does that make sense?


Edited by Blacksmith, 02 May 2018 - 11:27 AM.


#7 Bob Hudson

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Posted 02 May 2018 - 12:28 PM

Here's a few more forum threads about this topic: site:usmilitariaforum.com humidifier 



#8 Bluehawk

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Posted 02 May 2018 - 03:14 PM

The curatorial experience since 1975 in museums of every imaginable variety taught me the following with excellent results, for what it may be worth:

 

1. True, a relative humidity of about 45%  (i.e. above 25% and below 65%) is generally best for preservation of artifacts.

2. Equally important however, is maintaining an ambient temperature of between 65-70 degrees.

3. AS critical, by far, is maintaining both relative humidity AND temperature at a stable consistent value.

4. The air needs to be kept moving, within reason.

5. University Products, a very reliable vendor, makes this hygrometer which will usually handle just about anything a normal person wants to measure:

https://www.universi...hygrometer.html



#9 Bluehawk

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Posted 02 May 2018 - 04:16 PM

6. Inherent vice - a small percentage of artifacts, such as perhaps the Heatab illustrated above, are just going to deteriorate under all but the most strident storage climate conditions, and maybe even then. Other examples include nitrate film (such as most old movies were made of), certain kinds of batteries, certain dissimilar metal alloys in contact with one another, some works of historical or contemporary art, certain mixed media artifacts, objects in which the process of deterioration/corrosion/rot have already begun and the like. 

 

7. Hygrothermograph - This device is useful in some applications such as large collections in different rooms or rooms/spaces of differing sizes. What it accomplishes is to tell us what is basic common sense (i.e. relative humidity and temperature fluctuate over time, and by how much, within what range) but mainly to signal anything highly unusual about the stability/consistency of storage climate, which needs immediate attention.

 

8. Humidifer - As has been many times stated, using the best possible and/or professional grade machine is usually best, because it can be calibrated and regarded as effective.



#10 plick27

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Posted 02 May 2018 - 04:49 PM

These are the loggers we use at work.
https://www.grainger...m_vc=IDPPLARECS

Used the grainger site because it lists all the specs. Have seen them as low as arorund 60-70 dollars other places online. The are very accurate and will plot temp/humidity to a graph. It also calculates and plots dew-point.

#11 Bluehawk

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Posted 03 May 2018 - 04:56 AM

Yup, Grainger

 

I always forget about Grainger. Amazing company.




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