Fungus growth?!

superviper88 wrote:

I live in a humid/tropical region and  have a frustrating problem: my finished models displayed in an enclosed display cabinet tend to have some strange small spots growing on them after some time, could be fungus/mould/mildew spots?.. My models are painted with Tamiya acrylics.. and even a Panzer 4 with a flat topcoat shows such terrible spots.. Could someone please tell me how do i remove and prevent such 'growths'?? Thanks a lot!

I have a friend who had the same problem in his humid midwestern basement. What we did was to use either a solution of copper sulfate or Lysol cleaner. I would recommend the latter, as copper sulfate is very blue in color and will stain the paint. This method is also used to remove organic growths from the exteriors of buildings.

Make a solution of Lysol liquid, remove the models from the case and wipe down the entire inside with the solution. Do not rinse. You may want to repeat this every month for awhile, then every six months.

Next, mist several light coats of the solution on each model. This will kill the organics, but the stains may be permanent, as the fungus or mildew may have changed the coating composition. You can try scrubing them with a cotton swab, but you may wind up removing the paint.

To prevent this on future models, you will need to do an experiment: mix up some paint for airbrushing, add a drop or two of the Lysol solution to the mixed paint, and put it in a tightly closed glass jar for a week. If the paint doesn't gum up (get ropey and stringy) or settle hard and clumpy, then you can use a few drops of the solution to help prevent the problem on future construction.

Hope this helps, and good luck.

So you think its the humidity that causes this?  I'm wondering if silica gel packs might be worth a try.  I've read lots of posts from people in humid areas who have had problems with there camera lenses getting a mold/fungus on there lenses.  I guess they shoot pictures during humid weather and then they put the lens in a camera bag only to find when they go to use the lens again it has fungus spots.  I've also read where people have just stored there lenses for a long time and when they finally looked at there lenses they had this condition.  What a lot of them have done was to put a couple gel packs in there camera bags (I always do this now since lenses can be expensive).  Not sure if this would work for your display case but perhaps its worth a try.  My guess is you'd have to put a few in there for it to have a chance to work and if it did work you'd probably want to put in new gel packs every so often.

Here's a link I stumbled across that explains what silica gel is   http://www.dehumidify.com/FAQ.html

Try a wash of very dilluted bleach  maybe 10:1................apply with a q-tip to one small area, and let dry.
do not apply too wet.................this will not only kill it....it will prevent it from re-occuring. just test the color fastness on a small area like I said. AND make some provision for getting moisture out of that case.

DO NOT USE AMMONIA ON IT!  Any type of ammonia-based product will remove the Tamiya Acrylic like paint stripper.

Wilbur Wright wrote:

Try a wash of very dilluted bleach  maybe 10:1................apply with a q-tip to one small area, and let dry. do not apply too wet.................this will not only kill it....it will prevent it from re-occuring. just test the color fastness on a small area like I said. AND make some provision for getting moisture out of that case.

Yes, the bleach will kill it, but will also have a long term effect on the paint—chlorine is a very potent element. It will also not be as effective, long term. We tried* bleach solutions on such growths, and while effective, well established colonies in a good environment eventually come back.

That is why I recommended the Lysol. It contains a chemical that remains resident for a long time. Treating the interior of the cabinet alone may be enough to prevent recurrance.

A dual treatment is also worth considering: dilute bleach, rinse, Lysol. If it comes back after that, I recommend thermonuclear weapons…

Getting the moisture out of the cabinet is a good plan, but may not be practical. However, there is something else that can be done to improve the environment: add one ore more bright light sources to the cabinet. Fluorescent light (cool white) will increase the temperature slightly, reducing relative humidity. Mold and fungus also generally do not prefer strong light, and that may help, too.

Good luck.


*This is based on extensive research for architectural restoration done by my former employer and others.

JohnGo wrote:

DO NOT USE AMMONIA ON IT!  Any type of ammonia-based product will remove the Tamiya Acrylic like paint stripper.

Not to mention the fact that some molds like ammonia!

Wow.. thanks for the advice guys..!

I will definitely remember this when I retire to Florida in a few years. I had trouble with mold when I was in FL a few years ago, it happened mostly in glass display cases. All the models I had stored in cardboard boxes did not have the problem. I always attributed it to lack of air curculation, but the boxes were tighter than the display cases and hidden in closets where the circulation was poor. Go figure.

Many cardboard boxes contain chemicals that act as fungicides, either intentionally or unintentionally. Additionally, cardboard is mostly fiber—low nutrient value even for fungus. Inks, paints, etc. are organic molecules, frequently containing something the fungus can break down.

Wierd - I've been following this thread for a bit and never had that type of thing happen.  I live close the the Gulf Coast, with a lake to the west and marshes and bayous to the east and never had the problem, mine are in a glass display case now so I will be watching for this...

Tom, is your house air conditioned? That would help considerably. Ironically, older air conditioning that has not been cleaned adequately can be a source of the problem.

I have the exact same problem. Models were painted with Tamiya acrylics and stored in a closed cabinet. I saw some kind of green fungus growing on them so I took out my trusty make-up brush and they flew right off. I'll probably try to put some kind of silica gel in there and see if that works. Otherwise I'll just need to dust the models now and then.

Same thing here.  I keep my models in a case with glass doors.  An interesting thing I never knew before was that you can microwave silica gel to dry it out then keep reusing it.  I wonder if any local stores in the area might carry silica gel packs or if its something that has to be mail ordered.

Mold is a very big problem, one that I have faced many times in my architectural drafting & design field.
Some basic steps that can be taken to help in our display cabinets would be to -

• Allow fresh air circulation. Either a vent on the bottom and top or better, install a small fan on top.
• Most mold spores prefer darkness, though some species grow in intense lighting also. A UV light helps. Same principal as used for fish tanks, kills bacteria and algae spores.
• Keep clean and dry. Setup a regular cleaning routine, every two weeks or once a month wash out the display case and all the models with a bleach/Lysol solution.
• Even if your home/room is air conditioned, using a dehumidifier is sometimes necessary. A/C units put excess moisture back into the air, [cause condensation of the humidity in the air].

Hope some of these tips might help you keep the green off your models. 

Save up those silica gel packs you find in electronics packages to put in with your models. They work wonders in extracting moisture out of the air, and you really shouldn't be eating them anyway!

Bgrigg wrote:

Save up those silica gel packs you find in electronics packages to put in with your models. They work wonders in extracting moisture out of the air, and you really shouldn't be eating them anyway!

But Bill, how else is a retired rock-head like me to keep up his silica content?!

Kumy wrote:

An interesting thing I never knew before was that you can microwave silica gel to dry it out then keep reusing it.

This does not work with all silica gels—and microwaving is not the best way. Put them in a glass container in the oven at ~250°F for a few hours.

Kumy wrote:

I wonder if any local stores in the area might carry silica gel packs or if its something that has to be mail ordered.

A good source is Dri-rite:

The Dri-Rite Company
13116 S. Western Ave.
P.O. Box 389
Blue Island, IL 60406

Tel: 708.385.7556
Fax: 708.385.0622

Email: info@dririte.com

Their web site is currently down for "improvement".

Ok fellas here is a great place to get silaca gel I used to work at a crafts store that had a floral arraingment section most dried floral shipments come with DOZENS of the lil packets in them I worked there about 8 years ago and i have bags with hundreds of them stashed away.Ask the manager if next time a shipment comes in if they could toss the packs in a bag for you,and tell them why you need them. and some floral sections have silica gel in 2-5 pound tubs for drying your own flowers just get some of those disposable ladies hose socks and put some in ( my girlfriend was not pleased for wasting hers LOL )tie the lil pouch off and TA DAAAA. I never had the fungus probs with my models ( i use enamels mostly ) but the stuff kept my paintballs from swelling due to humidity until i could use them