Cleaning a Gun's "Furniture" question

[JTHunter]

In looking in my wood & glass gun cabinet, I noticed some fuzzy-looking patches that I thought were were some "dust bunnies" of various sizes (pinhead to 1/4").
But they weren't.
they appear to be some kind of mold spots on the surface of a Mossberg 500C 12 ga. pump.  And they were only on the fore-end.
Here's the other weird thing - there were some even smaller spots a Marlin 1894 lever-action with a few whitish specs actually on the barrel !  And there were 4 other guns between them with nothing showing on them. 
I wiped the fore-end of the Mossberg with some 91% IPA on a paper towel, then used a blow dryer to dry it quickly.
The cabinet is in my bedroom, against an inside wall, so how could this be mold?

[Opportunity]

I think the reason is still the humidity in the air. Perhaps your home is near the coast? I observed this on my Beretta (it appeared literally overnight), but then we were hunting in a bay, where the water was quite salty and moisture probably got onto the surface of the barrel...

[MechAg94]

Does air circulate through the cabinet at all?  Could some humidity get trapped?  I am near the Gulf Coast.  Depending on weather changes and such, sometimes the house gets more humid than others.  That is one reason I like to drop the temp in the evening to the low 70's.  It does seem to dry things out better.  My safe is inside in the AC.  I haven't noticed rust, but I need to keep an eye out for that.

I have heard lots of people talk about doing a PM on all their guns once a year.  All I can suggest is wiping everything down with gun oil.  It has been a while since I have pulled out some of my guns.  I may need to do that soon.  I have some days off next week. 


The other thing may be to look at the oil you are using.  Maybe something about it doesn't protect as well or is susceptible to whatever mold you found.  A recent Dan Wesson manual recommended FP-10 or Militech oil instead of the oils I have been using.  I got some FP-10 recently and like it.

[WLJ]

I have heard lots of people talk about doing a PM on all their guns once a year.  All I can suggest is wiping everything down with gun oil.  It has been a while since I have pulled out some of my guns.  I may need to do that soon.  I have some days off next week. 

And remove the stock too one in awhile if possible when doing a PM. Seen guns that looked perfectly fine outside of the stock that were rusted up badly under the stock.

[230RN]

I'm sure you looked this over:

https://www.epa.gov/mold/ten-things-you-should-know-about-mold

The individual and "random" places could be due to insects landing on those "random" spots and leaving either mold spores or salt spots.   The footprint spots may not be "random" according to the insect and insects do not respect cabinet doors.

Salt water bay, eh?

It may not bear on this case, but as a general principle keep in mind that salt from ocean spray can travel long distances on an ocean breeze in the form of microscopic salt particles left floating after the water from the spray droplets evaporates.  Lived surrounded by salt water for 23 years and rust prevention on tools and such was a constant battle.

Ah, that beautiful salt air smell!

[JTHunter]

While humidity is a possibility, there is no salt as I'm in IL-ANNOY a little east of St. Louis.
There is a vent in the floor about 3' away from the cabinet about in the "5 o'clock" position and doesn't blow directly on the cabinet.
No, the door isn't "airtight" as it rattles slightly but I only get into it maybe once a year to wipe the guns down.  I have never had anything like this show up before and that's why I asked.

[HankB]

You might consider something like a Goldenrod heater in your wood-and-glass gun cabinet. By raising the inside temperature just a couple of degrees it ought to reduce the relative humidity inside and discourage mold growth.

I've been using a couple of canisters of silica gel in my gun cabinet to keep the humidity low for several decades and haven't had a problem yet - the only thing is, I have to "bake" the canisters in my oven a couple of times a year when the indicators turn pink to drive off the absorbed water.