howdy, i am modeling glennwood springs canyon in colorado on a section of my layout. I have constructed a mountain on one end of my layout that is about 3 ft tall and 3 or 4ft in diameter it is on a loop. The mountain is made of cardboard ribbing and covered with plaster cloth. My question is does anyone have any suggestions for an inexpensive way to create the canyon walls? I have used woodland scenic molds in the past i have about 7 or 8 different molds and then sculptamold them togeather. What i really want to do is create some different looks because the molds start looking all the same. I thought maybe using durahms water putty and then sculpting my own rock formations into the sides of the mountain. ANY one have good ideas on what i could use would be great. to hear. Thanks scott
bunsniffing my way through the rockies
Years ago I made my own molds using a product called Mold It , which is Liquid Rubber Latex. While this exact product is not made now , I am sure there is liquid rubber latex around , maybe at a craft store. Anyway you get a rock you want to use for the mold , wash it good to remove dirt etc , then brush several thin coats on the rock letting each layer dry. after a few layers I use cloth gauze to strengthen the mold , by brushing a thin layer and while wet gently pushing the gauze into the wet liquid rubber , then when it dried i put another layer over it. When all is done just peal off the mold . I found large rocks and used one side of it to make the mold so its kinda flat.
Hi Scott.
I'm very partial towards rock molds from Bragdon Enterprises. Joel Bragdon was a double major in college in fine arts and geology. He not only knows his rocks he knows how to model them.
Check out Joel's website. He has photos up for most of his molds. Most of the molds are under one square foot, but come are quite large. You could easily cover your canyon walls without it looking repetitious.
I own a couple dozen of Joel's molds and they have proven VERY durable. I build model railroads for a living and have been using some of his molds for ten years. Some of my favorite molds have been used well over a hundred times and are still in good condition. Joel has developed his own system for making rocks using poly urethane resin and foam. He has it down to quite a science and it works very well on large projects and modular layouts where weight savings is desirable. However, the system is quite messy and requires a lot of mold prep. Personally I prefer to use the molds with hydrocal.
Scott, do know what you mean about using the "same old" molds over and over for such large areas. I ran into this for a considerable cut (over 10ft long and 14" high). I can blend various molds and "play" w/ the strata on smaller spots, however, on something much larger I found that using the Cripplebush rubber rock worked out great. I would check them out. They can be a bit pricy, but a couple large molds will cover a lot of "ground" and work in rather quickly. If you had to go and buy a half dozen or so new or different molds this would be about the cost of one or more of the Cripplebush ones.
Modeling B&O- Chessie Bob K. www.ssmrc.org
When you make your own rock molds you only need to make them 1/2" - 3/4" deep. I can get several different molds off from rock giving me some variation. Also, if you have made them deeper, tilt the mold a little so that you do not always use the same spot.
To answer the "inexpensive" part of your question, have you thought of applying a thick layer of Sculptamold and shaping it with a palate knife or something similar?
I am not sure what the rocks you are trying to model look like, but for my "big" rock surfaces (not nearly as large as yours) I crumpled heavy duty tin foil and put in a layer of Sculptamold 1/2" to 3/4" deep. When they started to set up I pressed them into place. You could repeat this process, as you would molds and could cover an area quite rapidly. My largest one was about 6" x 18", but could have easily been larger. Mine are put on a foam base, but a plaster cloth base should work just as well.
Good luck,
Richard
You can use foam to make some rock outcroppings. If I don't have a lot of room I will cut off a thin slice of foam as if I was cutting a slice of bread. You can go quite thin in your slices. I caulk it in place and paint it up. You can get a very large piece by cutting the large flat surface off a sheet of foam.
Note the thin slice in the left side of this tunnel portal. It transitions between my cement rock face and tin foil tunnel liner. Once painted it blends the two together seamlessly.
Once painted up foam makes a good Rocky Mountain granite.
Good luck.
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
You can also use crumpled up aluminum foil for rock molds. No two are the same and they are cheap one-use only.
Tare a sheet off, crumple it up some (not too much), straighten it out some, bend the edges up to form a tray, and pour in the plaster. From that point, do just like you would with a rubber mold.
I like to put mine on while wet because it conforms to the surface and you can over-lap them. You do have to let it cure until you can pick it up and it cracks a bit but is still thick like batter. Takes a few times to learn to do it that way.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
Some observations based on my experience:
Model from nature: You mentioned a specific area that you are modeling. Use color photos from that area when doing your rock work. This will help with coloring and rock formations.
About Plaster: Hydrocal or casting plaster are my favorites. Cheap in big bags from the lathe and plaster store. These plasters set up hard as stone and take colors very well. I don’t recommend the WS light hydrocal as it is expensive and not as strong as the other plasters I mentioned. All plasters absorb water over time and eventually go bad. If the plaster doesn’t generate heat when it sets, it is probably bad. Seal it water tight containers (five gallon buckets are handy) and don’t put bags of it directly on cement floors (water is absorbed through the bag very quickly). If train guys offer you left over bags from several years ago – pass. The plaster has probably absorbed water
Coloring rocks: Use your photos as a guide to coloring. I use water colors and stain the castings. Others prefer to seal the rocks and then paint with acrylics. I use a painter’s palette to mix colors. I usually work on a dummy casting that I test my colors on before applying to rocks on the layout. Helps cut down on gross errors. I have found that real rock in nature is much darker than I can achieve in the layout room. When I go for the same degree of darkness found in nature on the layout, the color is way too dark to look good under layout lighting. Remember - You can always add color and make things darker - very difficult to remove color to lighten the rocks.
A couple of methods that I have used:
Hand carving: I did this on my last layout. Very time intensive. I used hydrocal. Mix a batch and apply to the hard shell after it has stated to set. Start carving! You have roughly ten minutes before it turns to stone. I used a chisel and utility knife to chop, fracture and carve the material. You must work quickly and decisively. If you don’t like the results, no problem, tear em’ out with a hammer and start over. You might try using longer set patching plaster or retarder in the hydrocal for more time. This method is cheap and can yield good looking rocks depending on skill and type of rock being modeled.
Hand carving example: This canyon is all hand carved rocks. Took roughly a year (carving in the winter) to complete. Coloring is leopard spot technique using water colors.
Rock molds: I agree with Dave H in his recommendation of Bragdon. I have used his molds quite a bit on the current layout. I apply the molds to the base hard shell after letting them partially set up on the bench. They can easily be bent and curved to fit various areas. By flipping the molds and careful placement it is easy to hide repetitions. The rocks look great and this method is very fast relative to carving rocks. Have a bucket of water handy and as soon as the rocks get warm to the touch, pull the molds off and douse them in water. Clean them immediately or the plaster will set in the molds and be very difficult to remove.
I have tried the tin foil mold method and didn’t like the results. I have also made my own molds and have found that this can turn into a hobby all on its own. Bragdon’s molds are better than what I can make at home. Advantage of molds is great looking rocks and speed of application. Downside of molds is cost. Find some local modelers and share the cost of the molds amongst yourselves.
Mold example: Basic rock work in this section took one evening using molds. Coloring is staining using water colors.
Good luck with the project,
Guy
see stuff at: the Willoughby Line Site
I got together with some friends and bought a selection of molds and then we shared them. This works well and is much cheaper than buying them yourself for a one time application.
The tinfoil method works ok for background rocks or for transition areas between mold casting. I'd not use them on foreground scenery. They don't look right.
If you are carving plaster rocks yourself, then add a small amount of vinegar to the water that you mix with the plaster. This retardant will slow down the reaction time and give you more time to carve.
Have fun!
Scott Perry, Utah
Whether to use tinfoil rocks molds, depends on the type of rock you are modeling. Make a small one and see if it looks like what you want to model. Here in the NE where the Interstate blasted through hills, some rock faces do look just like the crumpled foil. Other types of rock, hand carving Sculptamold, carving foam or using ceiling tiles would look more appropriate.
I used Sculptamold rather than plaster in my molds as placement timing is not so critical and dries slower. I have not done any hand carving in moist Sculptamold or plaster yet.
For talus at the base of rock faces, I pour some plaster in a shallow tinfoil mold (need not be crumpled) and break it up into small chunks and stain it with the same colors as I use on the face above it. You can also use pieces broken off the main casting that were broken off to make it fit properly.
I use Color-Rite rock molds; they are more flexible that the WS ones. I do not have a local source for Hydrocal; I use plaster of Paris.
I mix plaster with water until it had the consistency of a thick soup, like pea soup. I pick up the container and inch or two and drop it a few times to get the air bubbles to rise to the surface (just like my mother did with cake batter).
Spray the mold with water with a few drops of dish detergent, this acts as a parting agent. Pour into the mold, and let it sit for a few minutes. When you can pick up the mold and the plaster surface starts to show cracks unstead of flowing, it is ready to apply to the surface. Assuming you have a hardshell plaster or plaster cloth surface, spray the surface with water using a misting bottle - dry plaster will suck the moisture our of the mold and you will not get good adhesion between the mold and substrate.
Place the mold on the surface, and hold in place for a few minutes. You will feel the mold getting warm as the plaster sets up. After a few minutes, carefuly peel back a corner of the mold. If the plaster sticks to the mold hold in place for a bit more. Peel the mold off the casting, and check for voids, air pockets, etc. This is a good time to do a bit of carving while the plaster is still green (not set up hard).
Clean your mold as soon as you can after use. Roll the mold back and forth between your hands over a trash cans to remove the larger chunks of plaster sticking to the mold, then rinse it under running water. Let it air dry. If you put it away in a plastic bag damp. it may mildew.
George In Midcoast Maine, 'bout halfway up the Rockland branch
Thanks for the suggestion i went to my local hobby lobby store and they had a similar product called morld builder. I am in the process of molding my first rock casting. I also found an article in mrr hobbyist that suggest using silicone but i tried it and only was able to make a huge mess! The idea is good but the part that is hard is spreading the silicone with my finger it tends to just want to stick to it and pull the mold up off hte rock.
Thanks for all the input. Your canyon looks great. One problem that i run into when coloring my plaster rock molds is trying to get a good reddish color without turning them pink. I mostly use the painting a base color tech and then using acrylics to get the end result. Any help on this subject would be great. thanks,
Has anyone ever tried a "mold exchange"? Maybe an honor system of borrowing molds for several weeks and then returning them to owner or on to the next user.
Perhaps a system in place to keep the dollar values equal for direct trades. For instance person "A" has 5 Bragdon molds (numbered and having a value of say $75 dollars) He could exchange them with person 'B' who has 4 molds having a value of $60 dollars. "B ' trades with 'A' and pays the difference of $15 dollars.
Just a thought......
Mark B
Start by dying the rocks with a base color. I use Rit Dye in liquid form (crystals work, too.) I put a half teaspoon full into the water then mix with plaster. This gives the plaster a base color which makes your add on colors look better. It also prevents white spots when you chip the plaster. It works great. Oh, and the RIT Dye is acidic, so it slows down the drying process giving you more time to work.
A group I belonged to just had everyone donates some molds and we put them in a box, then anyone could borrow the box. Worked very well.
Have used Grand Central Gem molds for years, in particular the mold in-place shallow relief versions. I need to cover a large are 24" high by 20+ feet long. Just received 5 new 17 x 10 molds where 3 are variations on a theme if you will, for combining into large areas with pattern similarity but still yielding variety.
Thanks again for all the ideas and examples. I molded some of my own rock formations which turned out pretty good had to do some carving to give it a better look, i also have 3 bragdon molds on the way and am excited to see how they work. They look really detailed and realistic looking so wish me luck hopefully by mid febuary i will have an awsome glennwood springs canyon.