Working with Sculptamold

Model Railroader Layouts and layout building
1

Hello Everyone!

Does anyone have tips on working with Sculptamold? I have used it in the past and I followed the instructions on the package. Once I have it mixed with water it is the consistency of oatmeal. After it has dried I have tried to sand it, and it seems like some of the material is not getting saturated with water. I think I may not be mixing it enough, or using enough water. Has anyone tried to mix this stuff in an old blender, or is that not a great idea?

Any help is appreciated!

Kurt

2

I have used Sculptamold in castings, as butter between castings and just added over foam, never tried to sand it. Since it is a paper mache like product, I would think the fiberous nature of it would be difficult to sand smooth. This may be what you are encountering.

Good luck,

Richard

3

Kurt:

I’ve used a lot of Sculptamold and I know what you are observing. Using the recommended ratio of two parts Sculptamold to one part water yields a mix that, as you have described it, resembles oatmeal. When dry you will observe “lumps” that don’t take water based stain giving a kind of speckled look. It doesn’t sand well as you have observed. This is due to the composition of the product which is plaster and cellulose filler. The cellulose is what is forming those lumps. I don’t know if blending will cure the problem but if you are feeling adventurous try it and let us know. Good luck.

Joe

4

I have used this in the past and experienced the same thing you have. I did try placing the water and sculptamold in an old milk cartoon and just shook the heck out of it…that seemed to help. But I haven’t used this product in a number of years, so I don’t have any recent experience with it.

Good luck,

Wayne

5

Kurt, that was my experience with it when I first started doing scenery. I switched to mixing it with Structolite, and used that mixture for all my scenery. I put a cup of water in a Pyrex mixing bowl, add a cup of Sculptamold and mix it with the whisk. Then I add a couple of cups of Structolite, 1 cup at a time, and mix some more. When the mixture is too stiff for the whisk, I switch to a plastic spatula. I’ve sanded and used a small Surform to smooth some scenery, (roads or parking lots). The Structolite contains fine perlite, that in my opinion, yields great scenery.

An in process shot.

Finished scene.

DJ.

6

I find that Sculptmold is too easily damaged when used alone. For river and lake bottoms and sides, I suggest that you use Hydrocal plaster, which is extremely hard and does not leak water. For mountains, I apply stain to a mixture of Sculptmold and Hydrocal plaster. This way, if some does chip off, the under color will provide the backup coloration. For areas that get extensive hands-on use, I use Patching Cement. For large harbors, instead of resin plastic w"water",I suggest the use of random patterned door plastic and paint the bottom a uniform dark blueish green, to indicate fairly uniform depth of water. By painting the bottom, the top surface will still sparkle. Bob Hahn.

7

I have used Sculptamold for years. At present, I am making my “to the ceiling” mountains. I use cardboard box strips glued with a hot glue gun. I then cover this with casting plaster used by doctors (or from Woodland Scenics). Then comes the sculptamold. I usually make with the “oatmeal” consistency. After I have spread it on, I let it begin to dry for about 15-20 minutes. I will use a spoon (bottom end down) and smooth out the material (or use an artists knife. If the sculptamold is too dry then I will wet it with a spray bottle of water. I am able to smooth out just about any form that I need. I also apply rock castings prior to the sculptamold step. I use “liquid nails” to get the castings to adhere to the plaster casting material. I paint all sculptamold with a brown acrylic paint.[:D]

8

DJ,

Love your work!!. I would like to see more of your layout!!. When I finish the current mountain, I actually plan to take a few photos and put them on the Forum.[;)]

9

I’ve been using Sculptamold over extruded foam to make scenery for years. I mix it using warm water, and stirring constantly. I probably used a little more water than recommended by the manufacturer, and although it is the THICKNESS of oatmeal when I’m done, it isn’t the CONSISTENCY (that is, not very chunky). Those chunks are ground up newsprint, and they do get saturated and behave nicely if you add water gradually at the end and stir it in thoroughly.

While Sculptamold can be sanded when dry, when I want a smooth surface I do the following. Let it set up for a couple of hours, then use a rasp to shape it to the the shape you want. Then, wet your fingers and rub the remaining surface smooth.

Like the previous poster, I find that painting it with acrylics or latex house paint works better than stains.

10

I use Sculptamold to fill in between urethane rock castings. I then paint paint the whole cliffside with flat, white, latex wall paint and let it dry thouroughly. A 60-40 (paint to water) coat of tan latex paint is then used to get the base color, followed by thin washes of india ink (don’t overdue the ink wash) and Woodland Scenics stains to add variation, and it really looks good to my eyes. Here a couple of pics I posted before showing the first two steps in the process. The area in the lower right corner is all Scultamold, and I to my eye it has a nice loose rock look to it. In these shots the washes have not yet been added.

11

Try experimenting with more water. Not much more, but a little. It sounds like you’re using it at the dry end of the mix.

I don’t bother measuring water into Sculptamold anymore, just run some water in on top of the dry, give it a couple of stirs, run some more H2O, repeat stir, until I get the texture I want. I use a stiff metal scraper to mix with, as you can just run the Sculptamold stuck on its blade off on the rim of the can.

When I’m stacking it into hills or other thick layered applications, I mix it towards the dry end. This helps these areas lose their water faster.

In places where I want a smooth surface, I mix it fairly wet, as this smooths easily and nicely.

Then there’s everything in between. Go ahead, try different things, it’s a very forgiving material to work with, unlike hydrocal and other plasters, etc, which require a pretty strict mixing ration with water.

Also, don’t mix too much at a time. If you find it getting stiff towards the end of the batch, it sometimes won’t stick or work as well. It’s definitely more of a PITA to work with then, anyway.

A couple of tips on embedding plaster castings. I usually just embed them in wet Sculptamold. I heard it helps to wet the plaster, but they seem to stick to the Sculptamold plenty good either way. Latex adhesive is probably overkill, but I won’t diss anyone who wants to use it.

Be careful when trying to color plaster and Sculptamold. If you tint it, the two substances take up the color differently. The idea of putting a base coat over the entire area is a good one, as that will help seal the surfaces so that they absorb at the same rate. However, the paint will keep the plaster from absorbing the tint, so you’ll lose some of the nice subtleties that can be created with tinting methods.

12

Thanks for all the helpful tips! I am going to try the trick of smoothing out the Sculptamold with the back of a spoon while it is still wet. Also, some complimentary products such as Hydrocal and Structolite were mentioned. Are these products that I can get from my local hardware store/home improvement center, or do I need to go to my local hobby shop?

Thank you,

Kurt

13

If your local hardware store does not have hydrocal, plaster of paris is a very close substitute. Structolite is a brand name, another brand of a similar product is Gypsolite. I have only found it in a 50# bag and being a small store they had to order it.

Good luck,

Richard

14

I work in small batches and use craft acrylic paints to tint it while I’m mixing. That eliminates the white chunk problem, and the paint also extends the working time a bit. The spoon trick works for smoothing the surface… think of it like pumping mud, forcing the dried bits down and releasing the water up. The sediments in the water eventually give you a smooth surface.

Lee

15

I am with mlehman, experimentation is the key. I only measured the first two times I ever used it. Now I just add water and mix until I am happy with the consistency.

I also let it dry for a while then smooth it out by hand or with other tools. Depends on what result I want as to how I actually do it. I also have a cup of water to add little amounts to aid in the smoothing process. I have found that with different techniques you can get pretty much any look you want out of it.

I do stick with hydrocal for molds though as it flows better into the molds than sculptamold ever could.

16

Similar to the spoon, I sometimes use a metal jar lid for smoothing the surface of the Sculptamold. The lid works somewhat better for making flat areas…

17

You can also use a palette knife, available in various sizes at art supply stores, for mixing and shaping.

A thin bladed palette knife is a terrific tool for pressing crevasses into rock faces made with Scupltamold.

18

Hi, I am actually a painter and I have been using sculptamold to make a sort of relief surface to paint on. I have been struggling with orange mold. Have you had that problem? Do you have any suggestions? I have waited 3 days before painting and the mold appears before I even begin to paint. I have also been adhearing the sculptamold to canvas wrapped over a panel. Could the canvas be creating some of the mold? I am in florida so it is extremely humid, but i have been using a dehumidifier. Any suggestions would be greatly appreciated!

19

I haven’t had any issues with mold here, but it’s a dry basement environment with central air.

I strongly suspect the Sculptamold isn’t fully drying. You really need to do that at first, especially iif the surface will then be rewetted.

Do you paint directly on the Sculptamold or use some sort of primer, gesso, or matte medium to seal it it? Sealing the surface will avoid moisture building back up. It may not give the color response, etc thatan unsealed surface does, so it’s possible that won’t work for you.

20

My layout is in a basement which can get damp, and Sculptamold does take a couple of days to dry completely. However, I’ve never had a mold problem.

Basically, there are a couple of issues you might have. Mold needs an environment where the relative humidity is greater than 60% to grow. Your dehumidifier needs to be big enough to keep the humidity in your studio (or whatever) lower than that. You also need to be very conscientious about emptying it as soon as it is full, or a little sooner, because it doesn’t do any good if it’s shut off because the float trips the limit switch. Also, mold is carried by airborne spores. Try getting a HEPA air filter, which will remove spores from the air.

It is also possible that your canvas is the source of the mold, especially if it has been stored damp. After you stretch it on your frame, spray it with Concrobium Mold Remover (available at Home Depot and other fine stores) and let it dry completely before applying the Sculptamold. It will kill any spores that are present. You can also spray your shower (or sink, or any other nearby water source) with it, which will kill any mold lurking there.

Hopefully, these tricks will get rid of the mold for you.