Benchwork: Plywood, foamboard or both?

[ho/ttothemoss]

I've built two layouts both where track foam on too ply wood but this next one in my new house will be foam over plywood and my first time doing a shelf layout my last two where table layouts!

 

[flyboy2610]

Is it ok just to glue the foam to the plywood base?
Will painting the plywood help at all as far as expansion & contraction due to humidity?

Yes to both. Make sure that the adhesive you use for the foam is safe for foam. Some are pretty strong and will actually melt the foam. Tell the guy at the hardware store what you want and he'll see that you get the proper adhesive.

 

[CbarM]

IMO I think the best thing for a layout base is 7/16 OSB board...its cheaper then plywood and it is 100% flat and will not warp. I have used that in all my benchwork so far and its working out great! For my under table bracing and legs I have been using 2x3's, but I wish I had thought of the T-nut idea for levelling...but for now the atlas track cardboard package folded over under the legs is working hehe...

 

[videobruce]

Since I hate cheap OSB, I never thought of using it for a inside application as this.
The 3/8" sheets of ply that I had out in the garage for a couple of months did warp. After cutting into roughly 3x4' pieces and bringing them inside and priming them, they aren't too bad.

Here are pics of the finished room with the framework.

 

[videobruce]

Now with the primed table top in place;

 

[D&J RailRoad]

Videobruce, what did you use on the floor? It looks like its painted.

 

[videobruce]

Floor paint. Probably 3 coats.

 

[D&J RailRoad]

Floor paint. Probably 3 coats.

I meant what kind of paint? epoxy, latex, oil, etc.

 

[Beachbum]

I meant what kind of paint? epoxy, latex, oil, etc.

And what did you have to do to prep it before painting?

 

[videobruce]

Behr Porch & Floor glossy. They also have a Low Luster, but it is closer to a flat and hard to clean. I mix a gallon of each for my porches since glossy is way to slippery under wet conditions.

I just sweep and/or vacuum it first, then mop it and let it dry. No chemicals.

The only problem I have had is water seepage (before I got it under control and found exactly where it was seeping in through the stone foundation) where water sat on areas of the painted floor causing the paint to 'bubble up' making me scrap that portion, wait for the bare concrete surface to dry and painted tow or three coats just on that bare concrete.

If you look closely at the floor you will see it isn't flat or completely smooth. There are cracks with slight 'ridges' from ground heaves over the 95 or so years. (I love old houses, character no new house will ever have. )

 

[videobruce]

Painting a floor is easy as cake. I don't even use a tray. Pour right from the can with a plastic 'lip spout' and roll it on. One less thing to waste paint and clean up.

 

[GMTrainNut]

I'm considering using foam on top of ply for the new layout, but am concerned about the noise factor. I visited a layout once that was foam over ply, and the noise of the trains running, especially at speed, was irritating. It has me thinking about just sticking with good old wood and cork roadbed. But not having much in the way of a well stocked wood shop I'd like to avoid all the work of cookie cutter construction.

I've been told that 1) The type of adhesive you use to glue down the roadbed and track can make a difference, and that a flexible caulk is recommended, 2) the type of glue you use to ballast is a concern, and 3) once scenery is applied the noise starts to quiet down. That last one may be true, the layout I visited was not scenicked at all.

So I guess the temptation for me is the reduction in the amount of woodworking combined with the ease for sub-grade scenery.

I haven't cast my vote since I might be in the transition from plywood to foam over plywood!

 

[CbarM]

I think you might have it wrong GM...the foam over plywood is supposed to insulate the noise echoed up from the plywood. Thats what I have done with mine using 7/16 OSB and 1" pink foam overtop of that, with WS foam roadbed over that and it is about as quiet as running it on carpet. I think the best way to go about scenery is to get it finished before the ballasting, as thats how it is in the real thing...just my $0.02
Ohh...and I have used Elmers white glue for everything and it holds it just fine. Others will say it doesnt work but I say it does...

 

[videobruce]

I visited a layout once that was foam over ply, and the noise of the trains running, especially at speed, was irritating.

This is compared to what? That doesn't seem to make sense.
How about the room it was in? Hard or soft? Exactly how did the 'noise' compare to what you have heard elsewhere (other similar layouts)?

 

[GMTrainNut]

I'm sorry for not providing more information. The only thing I have to base it on is my old layout, which was homasote over ply in a carpeted room. So maybe since the visited layout was in a basement with a concrete floor that didn't help.

It just seemed that the noise of the trains running on the foam/ply layout resulted in a steady "hum" of sorts, I'm sorry I don't know how to describe it better than that. I guess you could say it was somewhat of a drum like sound. It's a sound that I would have expected on a foam only base.

I hope my questions or comments didn't upset anyone, that was not my intent. I'm just looking for the best method to use on my layout, one that is quiet and allows me to enjoy the clickety clack of the trains, and the sound equipped engines, which I usually run at a fairly low volume.

 

[videobruce]

The only thing I have to base it on is my old layout, which was homasote over ply in a carpeted room. So maybe since the visited layout was in a basement with a concrete floor that didn't help.

You just answered your question. I haven't seen/used Homosote in 50 years. Is that still made??
Concrete floor, hard walls vs carpeted room? Sure there is a difference.

It's a sound that I would have expected on a foam only base.

You mean expected on a plywood base don't you?

 

[GMTrainNut]

You just answered your question. I haven't seen/used Homosote in 50 years. Is that still made??

It isn't as nearly as widely available as it used to be, but can still be found. And Homabed still seems to have a bit of a following!

Concrete floor, hard walls vs carpeted room? Sure there is a difference. You mean expected on a plywood base don't you?

I actually think that foam by itself as a sub base would be louder than plywood as a sub base. The foam, to my ears, doesn't deaden sound like you would think it would, it seems to amplify it. Again, my experience is limited, and I'm only pursuing the issue because I like the pros of using foam, but just want to ensure I have a "quiet" layout.

I think I'm going to grab a 1" or 2" thick piece of extruded foam from the home center and do a little testing...

Thanks again for all the info.

 

[videobruce]

The foam, to my ears, doesn't deaden sound like you would think it would, it seems to amplify it

Anyone else comment on this??

 

[PaulB]

GMTrainNut,

have you done the testing yet? I'm interested to know about foam effects of sound whether it be one way or the other. I haven't used the foam yet, but it seems an interesting idea.

And I forgot to vote...doh!

Paul

 

[videobruce]

IOW's the foam acts like a sounding board with the plywood beneath.