I just bought a humidity tester and tested it in cabinet where I stored coins, I see an average about 54% (w/o dessicant) Is this too humid for coins? I place some reusable 40g dessicant and best I got was 47% humidity and I have to recharge them every 3 days. Do I need to use an electric dehumidifier? Thank you
54% is just a tiny bit on the high side. Ideal human comfort is at about 45%, in the low 30% range you'll start exhibiting symptoms of too little humidity, and coins do well in similar ranges. It's when humidity exceeds 60% that we start worrying. The simple expedient of keeping your coins in a (relatively) airtight storage container - with dessicants - makes this unimportant.
When you seal the coins in storage, you can add a humidity indicator. These usually have indicators at 30%, 40%, and 50%. The dessicant will absorb the moisture to below 30%, so the 30% indicator should be blue as you insert it and stay blue for a while. Eventually, as the dessicant absorbs moisture, the humidity will rise, and the 30% indicator will turn pink. As time passes the 40% will turn pink as more moisture enters the container through diffusion from the outside. When the 50% indicator turns pink, it's time to replace the dessicant and indicator. This might take 6 months, or it might take 3 years, depending on how airtight the container is. I store OBW rolls in sealed plastic and my indicators have lasted up to 3 years, though I had a few that showed 50% after 1 year. When storing this way, I recommend checking on them at least yearly.
Tupperware would be more economical, however don't you guys feel the need to showcase some of your collection? Maybe the cheaper ones in Dansco Albums or Silver Rounds in Lighthouse folders?
Generally, if you're comfortable, your coins will be, too. 54% RH is not insanely high. Keep in mind, too, that paper needs a higher degree of humidity than coins, otherwise it will get brittle. So, keep your bank notes and historical documents separate from your coins if you're using desiccant.
While I do understand what you're saying, my simple answer was always - no. I always believed that proper preservation and protection of the coins was the primary concern - not my own desires or inclinations. And, there are always the security issues to be considered if the coins are left out in the open. And not just from theft, but from improper handling done by those who don't know any better.
I took a quick look around the Internet and all are agreed that humidity is the #1 culprit against coins. But I only found 1 site that put a number to it. "According to Susan Maltby, vulnerable metal coins will start to corrode when the relative humidity in the surrounding air rises above 35 percent."
Unfortunately, at that point you'll be distinctly uncomfortable, with your throat drying out and sleep difficult.
Not at all. I heat with a wood stove and in winter the humidity is usually in the high 20s and I feel no discomfort. Of course, not everyone is the same so I cannot claim that everyone would feel comfortable that level.
Low humidity is bad? I live in the desert where its regularly below 20% with extended periods in the single digits. Today we are at 12%. Do I need to store my coins in a humidor or something?
If you can put them in a place with a reasonably uniform temp you're in good shape. I spent 1½ years in Yuma, AZ (Army weather). We officially recorded a humidity of 1% one time.
The AC will keep the temperature reasonably stable throughout the day, but there are seasonal swings from summer to winter.
The lower the humidity is the better it is for your coins. The ideal situation would be no humidity at all but that's pretty much impossible to achieve.
My house is generally around 45-50 over the winter time and more over the summer. This winter for Christmas I got one of those rechargeable dehumidifier that's small. I put my coins in my safe and threw that in there with a temp/humidity monitor. The last time I opened the safe it showed 37 and it was still charged up good. I should open it to see what it has got down to.
