Basing structures...

[JimF]

...to be able to add them to diorama after built.

Trying to decide how to base structures, and what to use.

For my in progress (slow) Horwood Bros. kit and my Carrick's Corner kit, Dario calls for 1/2" plywood to base the complete scenes on. I am wondering if 1" blue insulation foam would do, instead.

I have a small structure from a few years ago, with a foamcore base. The regular type, not gator board type. I painted both sides with a earth base color, mounted structure and did the small amount of scenery it needed. Has not warped at all, even having been in a box out in shed for about a year. I also have done a couple of small military models scenes in same way. All these are aprox. 2 or 4 inches by 4 or 5 inches. I'm wondering if larger bases might warp despite painting.

My Thames kit is mounted on picture mounting board, about 1/16" thick. The sidewalk is printed surface, attached directly to the board.

So, I'm very curious as to how others do it, and what they use.

Thankful for any input.

Jim

[deemery]

Foamcore would be good.  Gatorboard would be better.  That's because Gatorboard is completely waterproof, where plywood could warp or the paper cover on foamcore can peel off when exposed to water (from scenery).  The challenge for me is making sure whatever the foamcore/Gatorboard/plywood sits on makes the base plumb and level.

dave

[JimF]

Thanks for that, Dave.

The diorama base structure is 2 Woodland Scenics Mod-U-Rail 18"x26" straight sections. They are sturdy, I have them leveled and bolted together. I also have secured additional cross pieces, so my total top surface is now 30 inches x 6 feet.

Right now, there are 2 15"x72" panels of the 1"insulation foam as a table surface.

Jim

[jbvb]

A word of warning about Gatorboard: in 2011 a modeling friend used quite a bit of it as benchwork on his layout.  Not long afterward, he started feeling sick when he spent time in the basement.  I looked up the MSDS for Gatorboard and found that it outgassed formaldehyde.  My friend saw some doctors, who said he'd developed a formaldehyde allergy.

I just checked the Gatorboard MSDS again - the current one, issued in 2014, doesn't mention formaldehyde as a hazard, unless you burn the stuff.  Perhaps they changed the formula.

[Rail and Tie]

I am a big fan of 1" and 2" Polystyrene Styrofoam (The extruded pink or blue DOW stuff, not the popcorn stuff.) I have used foam core for some terrain layering but not a big fan as you need enough layers to get it to be rigid and as Dave mentioned, it has a tendency to delaminate when wet or just on its own after time.

Extruded Styrofoam is quite good, and I use 2" for my bases now. Caution if you use 1" or thinner for large area you can get some weird things happening if you don't reinforce the bottom or have it properly glued to your layout foundation. Since it is extruded, the top and bottom surface of the material skin over and set faster than the inside, causing the outside surface to be more stressed than the material inside. If you heavily sand that skin on one side, you will see it warp the other way as you sand away that stressed surface. I always rough sand the Styrofoam base so that plaster, glue, paint adheres better when making dioramas. I sand the bottom side as well to help reduce the potential warping problem. It is really only noticeable on larger areas. Ask me how I know that!! Shiny water surface that is not flat is really noticeable!!

That said, I am a complete convert when it comes to basing and layout base with Extruded Styrofoam. Way easier to carve and cheaper than Gatorfoam or any of the other signage substrates.