adhering to foam base

Hi Deemiorgos,

All the scenery on my tiny layout is various mixes of Sculptamold applied on top of an extruded Styrofoam insulation base. It's been on  the layout for over twenty years and there's never been a problem with delaminating.

Sculptamold is similar to Celluclay. Depending on what I was trying to model, the basic Sculptamold and water had yellow carpenters glue or acrylic matte medium added to help it adhere to the foam. But to be especially sure when the mix was going to be spread on top of the flat, factory smooth finish I poked LOTS of small, shallow holes close together, using a pointed bamboo skewer, all over the foam surface. In some places, for added assurance, I also poked holes in areas where the foam surface had been roughed up when carving and rasping it to contour the terrain.

The Sculptamold primarily was applied with a small, stiff chemistry spatula, pressing firmly to force the mix into the holes for a stronger mechanical bond. I used very thin layers of the mix (often less than 1/8 inch). When the inevitable tiny lumps of the mix dragged across the foam, they were quickly poked into the foam using the pointed spatula tip and then smoothed over.

Also, both acrylic craft paints and/or universal paint tints were added to the Sculptamold mixes to precolor them. The paints and tints do not affect the final strength of the applied mix. The precoloring created a starting point, eliminating the stark white. Additional staining and painting with acrylics or latex paints was done on top of the dried mix to give the area a realistic appearance.

There is a detailed article about all the ways Sculptamold was mixed and used on the layout in the November 2020 Railroad Model Craftsman.

billgill4,Thank you.Using

billgill4,

Thank you.

I mix paint

in with the Cellu Clay mix.  This provides consistent colour through the mix.  I really don't use a formula, I just grab a handful of Cellu Clay, add some water and a few squirts of craft paint, mix it up and then add water/paint until I get the consistency I'm after.  Works pretty well...

The ground cover here is my Cellu Clay mix, the mountain side is carved foam that is painted.

Here it is with more ground cover added...

adding glue and paints

Deemiorgos,

You can add the paint or the paint tint pigments directly into the mix as you add water to the Celluclay, same with the carpenters glue or acrylic matte nedium.

Think of it like mixing cake batter: put the dry ingredient (Celluclay) in a bowl and add a bit of water, stir it up so it isn't dusty. Add a squirt of paint, stir. Add a squirt or two of glue, stir some more. There really isn't a fixed recipe oops, I mean "formula". It changes depending on what you are using it for and with the weather. I use more water, glue, paint or matte medium if a mix will be used for paving roads so that it can be spread and worked to a very smooth surface. Less of those ingredients if the mix will be used for rough ground cover. 

Adjust until the consistency is what you want (I aim for a mix something like peanut butter for pavements and carving rock faces).

Practice with a few small batches and see what works well for you. One thing to note about adding paint and pigments to the mixes: in general mixes with dark paints and pigments tend to dry a bit lighter than they look when wet and mixes with light paints and pigments tend to dry a bit darker. So experiment with that too.

I ended up using non sanded

Removed

You made the right choice!

You made the right choice, the banks came out super!

billgill4,Thanks. The

Removed

"Ground-goop" recipe?

I recall from old magazines that some modelers were using (what they called) "ground-goop" made from a mix of Celluclay and some other material. Might anyone have any info on a possible recipe to create this stuff?

Set the wayback machine for 2010...

...and the first Ground Goop thread to pop up on the Google Search:

https://forum.mrhmag.com/post/ground-goop-who-uses-it-12186603

This thread had several recipes for "Goop:"

https://forum.mrhmag.com/post/goop-12196365

Thanks for those links, Jeff.

Thanks for those links, Jeff.

what is up with the removed

what is up with the removed posts?

-Doug M

Ground goop

I used ground goop extensively on an o scale club layout and it looked great. However, the surface is extremely rough and abrasive, to the point you can draw blood if you accidentally scrape your arm on it. OK if you’re going to cover it completely with a top coat of plaster or puff balls, but hazardous otherwise.