I have old Athern passenger cars, (factory painted) Some have developed a type of white colored mold? I have attempted to clean it off, but it re-truns after several weeks. Layout is in basement.
What causes this, and how to get rid of it?
ray
If it’s mold a mild solution of bleach and water should work. by mild I mean a ratio of 1:100 and if that doesn’t work then decrease the ratio. I will caution you the bleach may effect some paints so go easy.
The other thing is this may not be mold. If your cars are made of white metal or zinc plated then it maybe oxidation weeping through. The only other time I’ve seen white “mold” ison models of ships where the castings were made of lead and after 20 years they started to, first leach white, then crumble. I have never heard of anythig in the MR industry being made of lead. Unless they were using lead based paints when your car was manufactured.
Regards
Fergie
BTW Welcome to MR Forum!
could be a type of mildew, there are various cleaners on the retail shelves that are lables for cleaning off mold, granted they may or may not harm a painted finish. To keep from getting mold or mildew in a basement a use of a dehumidifier is a must, year around in some cases. I think humidity around 50% level is desirable
It’s desirable to find out if the material under the paint is metal or plastic.
Some zinc plated metals or zinc covered lead will start to oxide or leach out and present the white stain you and Fergie are mentioning. However that method of construction though no longer used, ocurred before WW2 on model trains and the staining was an early indicator of metal fatigue and deterioration. I’m thinking of old Lionel or Gilbert stuff from before the 1920’s.
If it is mold staining on paint over plastic, sometimes the washing will remove the active mold but the embedded stains will require careful and repeated washing for a complete removal. I agree with the washing methods described in previous posts (besides bleach is a great weathering agent!). The embedded mold sometimes grows into the paint layer and can be temporarily ‘erased’ only to show up when the piece is completely dry. This problen is similar to a staining agent used in a dishwasher to make the glass shiny.
Generally the stains caused by mold will be dark unless the paint pigment causes a reaction. The white color is puzzling.
Alternately, you may want to consider light sanding, recoating & redoing the cars depending on the age, actual construction and relative value of the cars. Your local hobby store might be able to assist you in the valuation before doing anything further. My 2 cents [2c].
As far as your environment goes, in addition to relative humidity, mold can and does grow on dusty surfaces, dirty concrete, and similar surfaces found in damp or humid basements. Even too much paper or cloth can provide the naturally organic food source mold requires. Also, good ventilation with a regular change of air is important in maintaining overall dryness (& preventing mold). While mold can be insidious, it’s really not if you annually dust and vacuum the basement, ventilate it and keep it dry. The August issue of Model Railroader features an article '10 steps towards running a better
First Athearn passenger cars are plastic no diecast or tinplate etc. Second, this is not mold. It is the wax added to tjhe raw plastic to make in flow better during the molding process. Sometimes they just mix in too much or it could very well have been off spec plastic that Uncle Irv got a deal on. I can’t tell you for sure how to clean it but it will be a challenge. You need something that will cut the wax and not harm the paint assuming you want to save the paint. Alcohol maybe, but people use it for paint remover so… I don’t think detergent will touch it but at least the paint should be safe. I have no idea about commercial cleaners, my only advice is be careful. It may not be possible to fix since it is a component of the plastic.
If it is wax then varsol or kerosene should remove it.
Regards
Fergie
Thanks for the interesting replies. Yes the cars are plastic and at least 20-30 years old. It almost seems that if there was a weak spot in the paint, such as at the corner of a window the mold would grow from the plastic through that thin spot in the paint. I tried a wash with soap and water and then with alchohol but the stuff returns in several weeks.
Right now they look like heavly weathered.
ray
For better of for worse, I have a dehumidifyer down by the basement empire. It’s in a pretty wet area, though, and this keeps the overwhelming moisture down. Before I put it in I lost a couple of Athearn boxes to mold.