black stuff on walls of Scamp

[patti-bill]

'm hoping someone can help us figure out what's happening with our Scamp. I'm attaching below part of the email that I just sent to Scamp in MN. We would appreciate any thoughts from this group as we deal with this problem.

Thank you.

Patti & Bill, Scamp owners in Wisconsin

*****

I'm attaching a few photos and hope that you can help us figure out what's up with our Scamp, a 16-foot deluxe model that we have only had for two years. We took it to our local RV repair guy and he had never seen anything like it and didn't know what to suggest.

In mid-September (2019) we were out in Colorado and experienced a very strong storm, lots of wetness in a brief period of time. Within a few days after that we started seeing black stuff on the wall, as shown in the photos. It was concentrated on the wood walls around the refrigerator--- on the left-hand side just as you enter the Scamp as well as on the wood section just below the storage compartment that is under the fridge. We tried to rub it off but it wouldn't come off. When we got home we wiped the area down. Last week we picked up the Scamp from where we store it and were dismayed that the black stuff was now covering more area, including the wood wall just above the under-fridge storage. Also, the inside wood frame of the under-fridge storage compartment was wet and black and the carpet inside the storage area was wet. There was some black stuff on the two end walls of the inside of the storage compartment. In addition, the throw rugs that we had on the floor of the Scamp (which were dry when we stored the Scamp at the end of September) were soaking wet.

What is going on? At this point the Scamp is unusable; we are not spending time in it because we don't know if this is mold or something else. Where would the water have come in, and should we have to worry about that in the next strong storm? That would not be acceptable - We realize this is a mobile unit but we bought it for that reason and should not have to worry about being out in the weather. At this point our insurance agent is saying it's not covered because it is a defect of the camper.

[CBG]

oooh. I would find that worisom, too. Please keep us posted with what Scamp says.

[k corbin]

That is not mold but I can see why you think it might be. Being a woodworker who sometimes artificially ages wood to a grey color with an iron/vinegar solution I do know what causes that black staining.

What you are most likely looking at is wet oak + iron equals black stains in the wood. The tannic acid in the oak reacts with the iron. You can see it a lot on old barns that have metal roofs or iron nails in the walls. Cedar also has lots of tannic acid and you will see black staining on cedar fences where the fasteners get rusty. So water coming in the vent, running over a rusty surface and then onto the wood and you now have big black areas in the oak.

I would suggest you get some oxalic acid or other wood bleach product. Remove the finish, bleach the area and then do a color matching stain to blend it in and refinish. Or of course prime with a stain blocking primer and paint the cabinets because sometimes you can't get all that black staining out. I once purchased a house with oak floors. The owner had a dog who peed all over the carpet. The steel staples in the carpet padding created black stains all over the floors. I bleached the floor and sanded it and got most of the stains gone. But it is unknown if you will ever get enough of it out to make it look really good again as plywood surfaces only have a thin veneer on it so you can't do a lot of deep sanding.

As that is a fridge up above that cabinet I would suspect the bottom area of the steel housing on the fridge got rusty and the rust containing water ran down onto the floor and cabinet front. I think you need to pull out the fridge, inspect it, if salvageable do some rust busting and put rusty metal primer paint on and then new enamel on the fridge housing parts. Then make sure your fridge vent has good gaskets on the edges to minimize water infiltration. Or possibly find a fridge vent that has deeper louvers to help prevent rain blowing in.

Another lesson to be learned from this situation. Always apply finish to the end grain edges of solid wood and also plywood to seal it. The end grain will wick up moisture and draw it up into the wood with capillary action. That is how trees draw water through the roots, up the trunk and out into the branches to the leaves and fruits. If you look closely at your stains you will see that is how it spread up into the wood. In wicked into the wood through those cut edges at the opening and down at the floor level.



Then do consider purchasing an RV cover to keep the storm water out of the RV.

[thrifty bill]

I noticed you said you had only had it for two years, but how old is the trailer (did you buy it new, or is it older)? Clearly water is getting into the trailer. Stored outside? Covered? Refrigerator vents?

If it is just two years old, I would be royally ticked off.


Trailers are designed to be outdoors. And people live in them full time. At the same time, one of the best things you can do to extend the life of any RV is to keep it under cover when not in use. Met a couple in CO last year, us with our 2013 Escape 19, them with a 2014 Escape 19. They wanted to know what we used to clean and polish our trailer as theirs was badly weathered and oxidized, while ours looked showroom fresh. I told them I have never polished it. But then the issue of storage came up. Mine sits under its own carport when not in use, theirs sits outside.

[ARVZ]

You know, I wouldn't be so sure this isn't mold without more information. Black mold spores will usually wipe off a non-porous surface fairly easily, although the molds are thoroughly permeating the material by that time. K Corbin has a point with the oak + iron stain, but that stain won't wipe off with a finger; it's has to be worked at with the proper chemical.



It behooves you to accurately identify what this is because most molds are very toxic. Some researchers say mold weakens the immune system so you become susceptible to all kinds of health issues, even interfering with brain function so you cease to protect yourself appropriately. I have been there myself...



This website has a mold risk calculator that will help you get a feel for what conditions mold likes: Dew Point Calculator


Not everybody can accurately smell mold, although it typically does have a noticeable smell. Because of olfactory fatigue, even people who do notice mold will lose the scent very shortly after entering a moldy room.


If you have access to a microscope, you can scrape off some black stuff and put it on a slide. Compare to pictures available online.


By way of prevention, fix the leak(s). Then keep at least a 30-pint compressor dehumidifier running inside continuously to dry things out and keep them dry. Get one with an exterior hose connection so you can drain the bucket out automatically through a hole you drill in the floor. Or you can set it over a sink, but then the drain water goes into the holding system. Set it at 40-50% RH because the controls and gauges are usually not accurate. One class of dehumidifier only works above 64 degrees F, the other class will work down into the low 40s: the cold temperature ones are far more useful in most climates. Any dehumidifier is a 2 COP heater, so it will help keep the trailer warm also, but only when the ambient air temperature is near or above 50 degrees. (Very cold air doesn't hold much water, so the dehumidifier won't run much when it's colder than ~42 F. But mold doesn't like cold either.)


At some point you need to do some deconstruction to see how far the black stains have traveled behind things. It all has to be uncovered and dried out a a minimum.



Monitor the indoor air temp and RH with one of these: This is great hygrostat with min/max memory: https://www.ebay.com/itm/ThermoPro-D...72.m2749.l2649


Dry this trailer out, keep it dry, and educate yourselves about mold before proceeding much farther. Any object that is porous can never be completely cleaned of mold, and mold will easily spread from infected objects to anything else. But the fact is mold organisms are everywhere, just waiting the proper conditions to thrive and multiply. A compressor dehumidifier is your best friend.



There may be some scope for mold control with a quality ozone generator, but you don't want to breathe ozone either, so it takes a good procedure and thorough airing out.

[k corbin]

I can see that people don't believe me when I say that the black stains are not from mold, that is was caused by water and iron. But maybe you will become believers if you see the information from a highly regarded source, a long published magazine "Fine Woodworking".
https://www.finewoodworking.com/2018...on-stains-wood
So there is your example of what the stain on those trailer cabinet is using an image showing the black staining in oak and also the instructions on how to remove the stain in a reprinted on the web article from Fine Woodworking. As I stated the stain can be at least partially removed with oxalic acid. The product they are showing to use is Bar Keepers Friend which has oxalic acid as its active ingredient.

Please quit scaring this owner with your tales about having it tested for toxic mold. This is not toxic mold or any other type of mold. Read the article and expand your base of knowledge, because not everything you will see on a piece of wood that looks black has to be mold.

[thrifty bill]

Regardless moisture is the cause. Finding and eliminating the leak is job 1!

[k corbin]

Remember, oak is high in tannins and wood species that are high in tannins are resistant to mildew and rot. No way will you get a bad case of mold on oak in such a short time. White oak is higher in tannins than red oak so it is often used in wooden boat framing, but red oak still has quite a lot of rot resistance compared to other wood species such as maple which has very little tannin content.

When I added blocking adhered inside of my shell so that I could have some thicker insulation I used western red cedar specifically because it is high in tannins and won't have an issue with mold and rot if moisture should get behind the walls.

[k corbin]

Originally Posted by thrifty bill

Regardless moisture is the cause. Finding and eliminating the leak is job 1!

The owners who posted about this issue know the cause of the leak and described it in their first posting.

[Jon in AZ]

Originally Posted by k corbin

The owners who posted about this issue know the cause of the leak and described it in their first posting.

They described a storm. Seems like the source of the water entry is not certain. Excerpt from the original post:

Originally Posted by patti-bill

... Where would the water have come in, and should we have to worry about that in the next strong storm?...

I agree with Bill. Find and stop the source of water infiltration, then decide how to treat the damaged wood.

It wouldn't hurt to take some active measures immediately to dry out everything as thoroughly as possible to prevent further spread of the stains. Open cabinets and use a dehumidifier and/or chemical desiccants.

[floyd]

To start... Open all interior doors remove cushions and turn the A/C on full with the trailer closed up and no one inside.
A/C is a dehumidifier.
Overnight should help dry it out.
You can then run the furnace. Once everything is dry then consider what K. Corbin said.


Also, I have seen moisture damage from wicking along the bottom of the wall. After cleaning and drying and eliminating the water source, you could remove that little 3/4" molding (mopboard) and replace it with a wider piece of oak trim.
Of course this is only after the problem is solved and you need a little cosmetic improvement.


I have Eggy-Sue (the pull-it surprize) , a 2004 Scamp13D.
I would be HORRIFIED to see something even close to what you have.
I am so sorry for what you are going through.
Please keep us posted.

[gordon2]

Originally Posted by ARVZ

...
It behooves you to accurately identify what this is because most molds are very toxic. ...

Not to me... most dont bother me at all.

If you believe Wiki, it says:

Molds are ubiquitous in the biosphere, and mold spores are a common component of household and workplace dust. The vast majority of molds are not hazardous to humans, and reaction to molds can vary between individuals with relatively minor allergic reactions being the most common.

[floyd]

Originally Posted by ARVZ

It behooves you to accurately identify what this is because most molds are very toxic.

Actually most molds are innocuous, very few are harmful to humans or pets.
Even most Black colored molds are not harmful.


Here on Earth, you would be hard pressed to avoid all contact with mold, radiation or Spiders!


Zinsser makes a great paint which proofs against mold and mildew...
it could be used inside cupboards and cabinets etc