Locos & Car Display?

[CBQ Fan]

So I have a bunch of equipment that doesn’t fit with my layout theme I would like to display.  My oldest son had me purchase some 8’ pressure treated 2x2 for a project he has long forgotten. I have an 8’ stretch of wall that I could mount the 2x2 to and space them apart to set my rolling stock on. If I want to get wild and crazy I could get some sheets of lexan to provide protection. This setup is just for me, not looking to have anyone come and view it.  It is so simple I feel like I must be missing something?!?  Thoughts?

[Ed Kapuscinski]

Dust. Don't forget about dust. It won't forget about you.

I think that's the reason most people use some sort of covering.

[Plate C]

I would not recommend the use PT lumber for this purpose.

[CBQ Fan]

I would not recommend the use PT lumber for this purpose.

Why not?

[MK]

I would be afraid of the gases and fumes that may ooze out of PT lumber from the chemicals they used to create it.  May react adversely with plastic or form a film of "gook" on metal, etc.

[Plate C]

PT material is generally intended for exterior applications. Also, it's mildly toxic and corrodes metals in direct contact, which is why stainless or epoxy coated fasteners
are required for use.

[peteski]

Plus PT lumber usually looks like crap (not very smooth and a bit greenish in color).  Doesn't it contain arsenic, or are the new formulas less deadly?

Yes, dust is the elephant in the room.  After few years dust seems to fuse to the surface it is on, so just blowing it off or even using a brush will not get it all off. Ask me how I know. Only way to bring the model to its original dust-free condition is to wash it with soap and water.  Imagine having to do this to few dozen of models.

While not cheap, I invested in several shelf units with a tightly fitting acrylic cover.  Dust free after over 10 years.

[wazzou]

CCA treated lumber has Arsenic in it, yes.
That treatment is really only available on Pole Barn sized lumber nowadays.  (No human contact)
However, nearly all commonly available pressure treatments are intended for decay, rot and bug defenses and contain chemicals I would not want indoors.
Plate stock on foundation walls are concealed in most cases or not in living environments.
I do a lot of Pressure Treated lumber in my business and we have a Trademarked proprietary treatment called Denali Gold that is a non VOC, non toxic pressure treatment but only for above ground use.

Bottom line…leave the treated lumber outside.

[CBQ Fan]

Interesting enough everything online said PT is safe indoors. That being said I am more concerned about the wood reacting to the trains. Dust on the shelf or on the layout is six of one half dozen of the other.

[peteski]

Interesting enough everything online said PT is safe indoors. That being said I am more concerned about the wood reacting to the trains. Dust on the shelf or on the layout is six of one half dozen of the other.

Do you believe everything you read online?    Besides, where is "everything online"?  Going by Bryan's credentials, I would take his recommendation.  But then again, we all do something that is not recommended, and we usually get away with it.
If dust is no object, then by all means, go for an open display shelf.

[CBQ Fan]

Do you believe everything you read online?    Besides, where is "everythgin online"?  If dust is no object, then by all means, go for an open display shelf.

Just stating the contrast. Must be google algorithm driven. Lol!  I have several passenger trains that are more modern than my layout timeline. So, I guess my point is that they can sit on the layout and gather some dust or sit on a display shelf gathering the same dust.  Either way I have to dust them ever so often.   

Your display case is very nice looking!  Impressive!

[thomasjmdavis]

Pretty sure that CCA (chromated copper arsenate) pressure treated lumber was banned (or heavily regulated and not in "home centers" at any rate) by the EPA about 10 years ago- so the modern stuff is not so dangerous as what some of us were chopping up 30 years ago (which was definitely unpleasant to work with). But I read that on the internet, so I'm not entirely certain.

When google searching on materials, start with the MSDS sheet (or in Canada, the SDS sheet).  If you look through it, you will be able to parse out the good advice from the bad advice available online.

The modern version that popped up in an MSDS that was the first hit in my quick search is for ACQ (as opposed to CCA) treated lumber, which is Alkaline Copper and Quaternary Ammonium, and may be more acceptable to the EPA than CCA, but doesn't sound like something I want in my bloodstream, lungs or eyes.  One major ingredient not obvious from the name is Monoethanolamine, which I will leave to the chemistry students to define.
https://www.msdsdigital.com/system/files/ACQ%20Pressure%20Treated%20Lumber.pdf

Here is the warning on monoethanolamine from the MSDS sheet:

MONOETHANOLAMINE. Inhalation of high concentrations of monoethanolamine has been
reported to cause pulmonary, liver, kidney and skin damage in experimental animals.

Monoethanolamine may be corrosive to the eyes, skin, respiratory system and gastrointestinal
tract, and may cause permanent damage to the eyes. Monoethanolamine may be absorbed
through the skin in harmful amounts and may cause allergic skin reactions.
Monoethanolamine exposures may cause damage to the nervous system, lungs, liver or
kidneys.

And read the MSDS for whatever brand you are using, so you know what is in it and additional safety precautions when working with it and/or long term considerations.  Also handy to have on hand if you happen to have an allergic reaction, as it gives the doc a place to start in figuring out the best treatment.

Sorry if I'm taking this too seriously.  Been the "safety guy" for a number of my employers. And I've cut a lot of wood.

[CBQ Fan]

I did find 2x2 oak trim boards.  If I go with this idea I will go with that instead.

[wazzou]

ACQ is no longer available because the “Q” (Quat or Quaternary) part has become unavailable to Koppers and other suppliers due to its importance in hand Sanitizer and other disinfectants, obviously heightened by Covid-19.
CA or Copper Azole has been the primary replacement.
CCA is still supplied and used, just not in consumer contact situations.

[Missaberoad]

How adept at woodworking are you?
If it were me I would rip pine boards (or hardwood if you want to get fancy) into 1/2 inch thick pieces.
Then build a simple frame with shelves on a plywood or Masonite backing board. Glue and pin with brads.

Rabbets and dados would provide strength but for n scale trains a backing board would be enough...

Something like this

https://www.tysmodelrailroad.com/2012/02/train-display-case.html

Using 2x material would waste alot of space IMHO... ...but that being said, you dance with the girl who brought you...