This may have been covered before, but I have yet another help request for my forums friends. What would be the best set of rock molds for moldeling sandstone in HO scale? I will also be using Scluptamold rather than using Hyrdocal. (I found, when I had to make an emergency repair, that the main section of my hill has gotten quite heavy over the years with all the Hydrocal tunnel portals and retaining walls that I have applied over the years. Unfortunately, scenery is my weak area when it comes to layout building (and all of us have one).
As usual, any and all help the forums can provide would be most welcomed.
I really like and can heartily recommend Bragdon Enterprises rock molds. There are many kinds of rock represented so you will have to browse his list to see which ones are most suitable for the look you want. Many of the Bragdon molds are fairly large so you can cover a good sized area with one casting. They are also relatively shallow saving plaster and weight.
I am a great fan of Sculptamold but not for rock castings. I think you will be much happier with Hydrocal. Or try the Bragdon two part epoxy method. Very light weight.
I punched up the company’s website and those molds were a little more than I had in mind to spend. However, I will keep those molds in minds.
Given that I don’t do a lot of rock castings, I have found Hydrocal tends to “spoil” after awhile. The hill in question is about 5 feet long and probably 2 - 2 1/2 feet long and I am not getting any younger on moving that hill. I have had pretty good luck on casting with Sculptamold. (Woodland Scenics tunnel liners).
I’m going to recommend using both the Bragdon molds and the two-part resin foam, if weight is a concern. The castings are very thin and light, unlike Hydrocal, and the resin foam takes mold details extremely well. The molds are far better than what you typically find at Woodland Scenics or other companies.
I still use mostly Hydrocal for my castings, but I’ve got one “signature scene” at the front of my layout that I wanted to make into a real focal point, and the Bragdon products really did that for me. I only used one mold for the whole scene. It’s a big casting, almost a foot square, and with a couple of castings inverted, cut and mixed around, there’s no obvious repetition of the pattern.
Over the weekend, I was at a show and I bought a second Bragdon mold from a vendor. I’ve got another vertical face to cover, and I decided to go with the foam instead of Hydrocal.
I think the Bragdon products take your modeling up a notch. Think of boxcars with metal grabs vs. molded on plastic, structures with illumination and interior detail, or nicely weathered trucks with metal wheels instead of plastic.
My only question is how the foam “keeps,” so to speak. Given that I don’t get a lot of time (a few hours a week) to do my modeling, I don’t want to get a large quantity of it only to find that it only lasts for a short time once opened.
I had mine for years before I ever opened it, and it was fine. Like Envirotex, it’s a two-part mix. I haven’t re-opened the bottles lately, but I’d expect them to still be fine based on my experience with Envirotex.
Bragdon is a one-man shop. Joel is responsive to e-mails, so if you have questions of a more technical nature, I’d suggest sending him a message.
I use Woodland Scenics rock molds with patching plaster. Patching plaster gives you a few more minutes working time but it takes longer to fully set up.
To get more use from different molds, try only partially filling them. This will give you some different shaped rocks. Try tilting the mold so only part of it fills or partally fills.
If you only partially fill the molds, the rocks will be thinner and can be broken into smaller pieces without a large ugly seam to hide.
I use pre-mixed drywall mud to attach the rocks to the hard shell scenery. By putting it around the edges of the rock, pressing it on the hard shell will cause it to ooze out around the edges. Then take your finger and smooth out the mud. You get a nice clean edge.
You can also use mastic that is used to put tile on walls, to mount your rocks. Sticks to almost anything and holds tight.