Beginning Terrain-Making Blog, Part 2: Using Silicone Molds

Tuesday, June 21, 2011

See Part 1 of this series.

At PaizoCon this year I ran a seminar/workshop introducing all sorts of things about making terrain for RPGs and wargaming. In between various demonstrations of hot wire foam cutting, casting bricks in dental plaster, mixing epoxy putty, and using polymer clay, I rattled off a bunch of websites with more information and/or product links. Here's a rundown on the information and links for plaster-casting and mold-making, just in case you missed the seminar.

A Hirst Arts cracked floor tile mold.

Using Silicone-Rubber Molds

Do you want to build a fort for your PCs to invade? What about a dungeon with customized room pieces you can move around? Or a display piece to hold your favorite miniatures? Building these out of hard plaster "bricks" is easy with the right tools. First of all, you need a suitable mold for the bricks you want. Hirst Arts Fantasy Architecture is by far the best site for buying terrain molds and finding tutorials on how to use them. The mold types range from simple rectangular bricks (like Wizard's Tower Mold #50) to flat floor tiles (like Cracked Floor Tiles Mold #206) to molds for ancient Egyptian buildings, gothic towers, or natural caverns. The molds are durable and easy to use, and last for hundreds of casts (I've had some of my molds for years and have never seen any wear and tear on them). For many of these molds, there are free downloadable plans for how to use that mold to build a sample structure (for example, the Wizard's Tower Mold instructions show how to build a multi-floor tower).

Excalibur dental plaster.

Casting Plaster

Once you have a mold, you need a casting material. Plaster of Paris (aka "POP") is cheap and available at hobby stores and school supply stores, but it's fragile and not good for long-term use. Most terrain-makers use dental plaster, which is heavier and much more durable than POP. The two most common brands are Hydrocal and Excalibur (the most durable); the best places to buy them are dental office supplier (find them on the Internet, the yellow pages, or check the Hirst Arts message boards for a good supplier in your area). Either type costs about a dollar per pound and is usually sold in 25- or 50-pound containers. Depending on the size of the mold, 1 pound makes anywhere from 2–4 casts.

Casting is simple: Mix the plaster with water evenly until it's about the consistency of milk, pour it into the mold, bang on the table to cause trapped air bubbles in the plaster mixture to rise (otherwise you get bubble flaws in the casting), wait 5–6 minutes for the plaster to start to harden and settle, scrape off the excess plaster so it's even with the top of the mold, wait 25 minutes for the pieces to harden, and pop them out of the mold. In my PaizoCon workshop, I spent a few minutes mixing and pouring the plaster, and by the time the seminar was done I was able to hand everyone a fully cast floor tile from the mold. The plaster dust can irritate your eyes and lungs, so you may want to wear eye protection and wear a cloth mask while casting if you're sensitive to that sort of thing.

Miniatures display platform.

Ideas for Projects

If you can build it out of bricks, you can create it—castles, retaining walls, ruins, wells, arches, and so on are all easy first-time projects. Cast the pieces, let them dry 24 hours, glue them together with Aleen's tacky glue, and you're done. Optionally, you can paint them (latex house paint is cheapest) to give them a more uniform color.

Sean K Reynolds
Designer

More Paizo Blog.
Tags: PaizoCon Terrain
Dark Archive

1 person marked this as a favorite.

Excalibur dental plaster ... my mom is an oral surgeon ... all these years I had no idea I could purloin her casting putty for minis ! She's retired but the next time I'm in San Diego I shall be raiding her garage in hopes of finding material. I may even luck out and find a Nitruous Oxide tank.

Thanks for continuing the series Sean.

Dark Archive Contributor

Great topic for the blog. I love these kits.


Have these temporarily or permanently replaced design tuesdays?

These are cool, but I really liked design tuesdays.

Contributor

No, they have not.

Paizo Employee Director of Game Design

vagrant-poet wrote:

Have these temporarily or permanently replaced design tuesdays?

These are cool, but I really liked design tuesdays.

They are just a temporary thing while we sort a few things out.

Jason Bulmahn
Lead Designer
Paizo Publishing


Pathfinder Roleplaying Game Superscriber; Pathfinder Starfinder Roleplaying Game Subscriber

I have to do some casting tonight actually.:) I have a Lepidstadt Courthouse to finish.

Dark Archive

I have wanted to get into making the Hirst Arts structures for quite some time. Debating on waiting until I can take the beginners course at GenCon next year or to just start now. Love the article though guys!!

Contributor

I didn't take a class, I just experimented after following Bruce Hirst's tutorials on the website. It's not that hard. :)

Dark Archive

Sean K Reynolds wrote:
I didn't take a class, I just experimented after following Bruce Hirst's tutorials on the website. It's not that hard. :)

Thanks for the boost Mr. Reynolds. Looks like I know what I am ordering next month!! :)


Don't wait. If you wait, then once you *do* start, you'll realize how much fun you could have been having and how many awesome pieces you could have already turned out in the time you waited. The learning curve really is small, I promise. The molds also work with resin, if you like that instead of the various plasters.

I'd like to point out that the Hirst Arts' Egyptian line can make some great Mos Eisley-style architecture if you are a SW gamer, too. And some of the stuff works well with action figure displays.


Pathfinder Adventure Path, Lost Omens, Maps, Starfinder Adventure Path Subscriber
Justin Franklin wrote:
I have a Lepidstadt Courthouse to finish.

Did you get the ziggurats finished yet?


Pathfinder Roleplaying Game Superscriber; Pathfinder Starfinder Roleplaying Game Subscriber
Dhampir984 wrote:
Justin Franklin wrote:
I have a Lepidstadt Courthouse to finish.
Did you get the ziggurats finished yet?

2 more paint colors and some flocking and it will be done.

Grand Lodge

Pathfinder Adventure Path, Rulebook Subscriber
Justin Franklin wrote:
I have a Lepidstadt Courthouse to finish.

You don't have your construction of that documented that you can share anywhere do you?


Pathfinder Roleplaying Game Superscriber; Pathfinder Starfinder Roleplaying Game Subscriber
Galnörag wrote:
Justin Franklin wrote:
I have a Lepidstadt Courthouse to finish.
You don't have your construction of that documented that you can share anywhere do you?

I am going to try and do something once I am closer to or done.


the Haunted Jester wrote:
I have wanted to get into making the Hirst Arts structures for quite some time. Debating on waiting until I can take the beginners course at GenCon next year or to just start now. Love the article though guys!!

I discovered the Hirst Arts molds about 8 months ago while looking for less expensive alternatives to Dwarven Forge. At that time my last experience with plaster had been during elementary school nearly 30 years before. I started with a couple of molds to make sure that it was something I would enjoy before I spent a lot of money on it. In case you are wondering, the answer was yes, I enjoyed it a lot.

At this point I have acquired nearly 30 molds and poured over 100 pounds of plaster mix. If you are a person who thinks you will enjoy this kind of creative outlet then I cannot recommend it highly enough.

I do suggest starting with just 1 or 2 molds and using the cheap plaster you can find in hobby stores so that you can get an initial feel before spending money on the more expensive stuff. The molds are amazingly easy to work with and have a very high tolerance for newbie mistakes. Do your homework first so that you get one of the more versitile molds and read the instructions on the site and you will have a very hard time going wrong.

As a side note, while the message boards for Hirst arts are not as active as here, the people are very friendly and encouraging.

Try it now, I think you will enjoy it and will do fine without the hands on demonstration.

Dark Archive

I am really enjoying the terrain-making blogs. I do hope to see more of this. =)


I just want to echo Mr. Beadrsley. These blogs are really helpful. I've been painting and making terrain since the mid-70's, and it's still helpfull to return to the basics for a reminder or two.

BTW, what are design Tuesdays? I think I'm missing something here.

Sovereign Court

Halidan wrote:

I just want to echo Mr. Beadrsley. These blogs are really helpful. I've been painting and making terrain since the mid-70's, and it's still helpfull to return to the basics for a reminder or two.

BTW, what are design Tuesdays? I think I'm missing something here.

The daily blogs are sort of themed and blogging responsibility divvied up, design Tuesdays are all about game design, rules and FAQ stuff.


Thanks for the quick answer Robert. I useually don't read the blogs unless the title catches my eye. I think I'll have to pay more attention to them from now on.


Wow, makes me feel old to realize I have Hirst Arts Molds from when he only had 10 different ones for sale. Have I really been doing this for 10 years now?

One trick I've learned through the years can solve two minor issues in one fell swoop, although you may want a 5 gallon bucket with a lid or two.

Simply: concrete.

Plaster of Paris can actually start to get expensive after a while, and dental plaster definitely so. And while dental plaster is great durability wise, Plaster of Paris it just doesn't cut it for pieces that are going to see use and wear. PoP pieces can be easily damaged with a fingernail, and while this can translate into a decided ease for carving, it can be a liability if butter-fingers or a random flying die get in the mix at the table.

So mix the PoP with concrete, in about a 50/50 mix. One bag of concrete will run you 3 dollars at the hardware store, which even after you filter out the small rocks, will leave you with over two gallons of the powder. The bricks you cast from what I call "Plascrete" will be much stronger, nearly impossible to damage with fingernails or dice, will resist breakage, and yet are still sculptable with proper tools. You'll double your effective plaster amount for a fraction of the cost, and increase durability immeasurably. Arguably, this is about 90% as durable as dental plaster, and often much cheaper and easier to get ahold of.

Some words of warning: Concrete has small rocks in it, which you can use for terrain details down the line, but need to be filtered from the powder to use the powder in a mix effectively (just try stirring and pouring into the molds with pebbles in the mix, not fun or efficient). You will need something to filter with and to filter into.

Which leads to the next issue: Filtering concrete is messy and dangerous. The powder takes to the air easily, and will settle all over the place. Absolutely filter outside if you can, or in the garage, or at least on a hardwood or tile floor. Use a filter that kicks up minimal dust: an actual filter like a strainer or such is far better than jury-rigging a terrarium cover screen like I did once. Never again.

You'll need a 5 gallon bucket to store your concrete in, which will eat up about 3.5 gallons of the space. A secondary tub for filtering might be nice as well, as well as a small container to store the useful pebbles. And finally, a container to store your Plascrete mix.

A lot of stuff and prep work? Maybe, although you probably have most of what you need already. A milk jug works for storing the plascrete, using the top of a soda two-liter as a funnel. Buckets cost about 5 dollars from the gardening center at major department stores, sometimes less at hardware stores. (They also make great storage for flour, sugar, and rice. Several in my kitchen.) Most have a strainer in the house, if only for pasta. Just make sure you strain it outside and wash off the strainer thoroughly.

Hope this helps someone!

Contributor

Thanks for the tip! :)

Community / Forums / Gamer Life / Gaming / Miniatures / Paizo Blog: Beginning Terrain-Making Blog, Part 2: Using Silicone Molds All Messageboards

Want to post a reply? Sign in.
Recent threads in Miniatures