# Help on mildew/ mold and flies on layout.



## musicwerks (Jan 4, 2012)

Dear all,

For 5 years I have used woodlandsenics materials (hydrocal, foam) with no problems.

Recently I tired using sculptmould, it's cheaper and pretty good.

Until I tried to make my own paper mache and a new hill making method. Learnt from a British model rail video.

A) I use soft green foam for flower arrangement to make the shape of the hills. Soft and easy to shape/compact

B) I mix woodland scenics smooth it and old tissue paper to make some paper mache material and spread over the green foam

C) I paint the semi dried, I paint woodland scenics yellow onto it.

D) then I do my ground foam, grass and turf materials as instructed Using scenic cement.

All seems nice until I get mildew and orange looking fungus on the foam and grass days later. Never have I experienced these. I also saw small fruit flies hovering around my layout.

I had to scrape away to bare ground level to destroy the mould. 


Help!!!! What went wrong? The tissue paper?


----------



## Lemonhawk (Sep 24, 2013)

My guess would be the green flora foam that absorbs water!


----------



## mesenteria (Oct 29, 2015)

The various products are all contributing to this unfortunate outcome in their own ways. First, that green mushy foam...it will retain moisture, as it was engineered to do, for many weeks unless you use a dehumidifier and let it dry out BEFORE you cover it with a product containing yet more moisture. Sculptamold and the other spreadable scenery goops just help to keep the green foam full of water. Molds are opportunistic.

If you find you really are better off starting over in some places, try this: let the green floral stuff dry entirely. It may take days and days in a cellar, unless you dehumidify. When you know it is dry (it's like a sheet of paper in weight), soak it again, but this time in a solution of potassium metabisulphite or sodium metabisulphite. Both can be had for pennies at your local beer or wine U-Brew It shops. Mix one heaping teaspoon in a quart of water, let it sit for half an hour, and then pour it over your green foam. Use the foam, and let it dry again, covering it when it firms up a bit and is obviously dry.

I always speed things along with a dehumidifier for this reason, and leave one unattended in my train room year-round. It tells me when it has worked enough to have filled its reservoir. 

When your sculptamold and other covers are mostly dry, spray them with the same solution of metabisulphite just enough that you know the top 1/8" is permeated with this potent mold, virus, and bactericide. Again, your dehumidifier will work to dry it out, and you should never have problems again. The metabisulphite will have sterilized that surface, and left sulphates and sulphites in among the molecules. If it ever happens that you can see mold starting again, the bisulphite doesn't last forever. Just spray anew.


----------



## gunrunnerjohn (Nov 10, 2010)

Heat would also help chase the moisture away. Put a couple of incandescent bulbs inside the structure to speed the drying process.


----------



## D&J Railroad (Oct 4, 2013)

Well at least you have some scale sized vultures over your layout.


----------



## CTValleyRR (Jul 26, 2014)

Since the OP is in Singapore, I'm guessing that he already has plenty of heat, and far too much moisture.

If your layout is not in a climate controlled space, where the relative humidity is kept under 60%, you're going to keep having mold problems.

There is a product sold in the US called Concrobium (a patented solution of Trisodium Phospate and Sodium Bicarbonate) that kills and eliminates molds and fuguses. It is non toxic and safe for layout-type materials. Once it has dried on your layout, it helps to form a barrier to prevent recurrence.

But your best bet is to eliminate the humidity.


----------



## Deane Johnson (Sep 19, 2016)

Clearly, it has to be a humidity issue. For a number of reason, including rust developing on metal surfaces, it would be best to get a dehumidifier and keep the room dry.

In the process, I'd vacuum all of the surface you can in order to gather up the mold spores and get them out of there.


----------



## musicwerks (Jan 4, 2012)

I dug out all the floral foam, only left with 1 piece. I cover the surface with enamel brown paint and used the dry method to create the ground foam and static grass.

I used 3M adhesive spray and did my scenicking as usual. I even used 3M spray for ballasting of tracks. No mildew or mould thus far.

I need to be mindful not to get water on this part of the layout from now on.


----------



## mesenteria (Oct 29, 2015)

First, I am glad you gritted your teeth and salvaged this part of your layout. I am sure you'll be glad to have experienced all of it, even if all of us would rather not have to. I have had to rip up a 3' ballasted curve because a new locomotive simply could not make it around it. 

Where you are, molds don't need the opportunity. The perfect conditions already exist, every day. Molds need 70% humidity typically, or more. You must be higher typically. Heat? Lots of temperature there. Food...molds will grow on most organic material. Spores? Everywhere, on every surface.

I have learned to live with the periodic cutting-in of my dehumidifier here in the Pacific Northwest of N. America. It keeps things stable...and predictable. It is the unpredictable phenomenon, but especially the one that keeps appearing from time-to-time, that kills the joy in the hobby.


----------



## CTValleyRR (Jul 26, 2014)

I agree with mesenteria that you seem to have ducked the humidity issue, deliberately or otherwise.

If you don't solve that, you will never have a permanent fix for the mold / mildew problem. You may have gotten rid of it for the time being, but it will come back.

I always advise people to keep their layout areas below 60% relative humidity to prevent the problem.


----------



## pookybear (Feb 3, 2011)

Good old fashion sunlight kills most mold and mildew. Barring you carrying your whole layout to the yard you can try a UV lamp for the same effect. You do not need to do it on long each day with a
lamp close to the effected area. 

Pookybear


----------



## mesenteria (Oct 29, 2015)

It'll have the added benefit of bleaching all your nice green ground foam scenic materials, too. 

And sun-rotting your plastic rail ties.


----------

