Arnica Sneak Peak: New Shed Design

Not much to report right now. My thumb is getting better and I've resumed my normal work schedule of casting parts and tooling (i.e. sanding) them. Orders are shipping and things are moving forward. The position of the cut does make it hard to mix mold rubber, though. Silicon rubber is very thick and holding the mixing rod puts a lot of pressure on my thumb -- exactly on that cut. So I won't be making any new molds for a few more days, yet.

When it heals I'll be focusing on making replacement molds for a few damaged parts, as well as making extras of key parts (like the wall of the bank, for example -- right now I've only got one mold for both walls and a second wall would really come in handy). After that, I'll move on to making some new molds for some new buildings, including the long-awaited Adobe collection.

We'll also be offering a new building for a set of original designs I've started working on: The Miner's Camp. You see, when we add the adobe buildings to our set, we'll have most of the major buildings that you need to create a nice Western town. The keyword being "nice." I'd like to add some more buildings that aren't so nice, nor so big. In other words, I want to create a set of small shacks and shanties like those you might find in a mining camp.

Here's a look at the first building I've designed (which, obviously, is based on our current Attached Shed).

New Shed Design

This photo shows the master pieces glued to a board that will serve as the basis of the master mold. As you can see, it will have a slopped roof with one end higher than the other. I'm hoping this will create a dramatic profile when compared to the other buildings in the town. Also, the flat roof (to the left) could serve as a place for outlaws to wait while ambushing people -- if the slope doesn't prove too steep, that is.

I'm also hoping that this model will offer a little variety to the various board & batten buildings we currently have. Also, it's a very small building, so it's low cost should prove to be popular. I've no idea yet when this will be released, but probably sometime this month. I'll keep you posted.

Remember, you can buy all of our Western Buildings at the Arnica Website.

See ya back next week for more behind-the-scenes fun.

Arnica: Sneak Peak Behind the Scenes

Not much time for blogging today. I'm busy pouring resin to fill orders, as you can see from these pictures of what I poured last night.

Here are the molds filled with tan resin on my work table last night. As you can see from the empty cups, I poured four cups of resin,. Each cup is 300 grams, so that means I poured 1200 grams of resin. That's about 42 ounces of resin, or about 2.5 pounds.

Here's the rest of what I poured. Today I will de-mold them and then store the pieces until I can sand them, which will probably be on Sunday. My goal is to pour about this much again tonight. In fact, I'm off Friday, so I will probably do an afternoon pour of roofs and extra bits that we like to keep on hand.

See you back here Tuesday

Arnica: Lights, Camera... Bubbling Rubber!

I've been busy this week on all things Arnica Real Estate. Not only did I get the new mold for the Boardwalks made, I also made a replacement mold for the side walls to the board & batten buildings. These molds got ripped to shreds last Christmas. One wall went because of malfunctioning mold release agent and the other went due to an error mixing resin. Mostly, though, they went because they were old and had outlived their capacity.

While I was making that mold, I whipped out my trusty camera phone and shot a short video of what the rubber looks like while we're sucking the air out of it in the vacuum chamber. It's not much of a video (just 2 minutes), but I think you'll all get a kick out of watching the rubber bubble around as it "came alive."

If you'd like to watch it over at YouTube, Click Here.

More About Molds

You see, molds don't last forever. As they age they get brittle and lose the slickness that is necessary for the easy removal of the cured resin. Without this slickness, the mold fails and tears when you pull out the finished piece. One question that's been asked a lot is, "How long do these molds last?"

The Arnica Work Table

Well, pilgrim, there ain't no good answer for that. You see, we use different types of silicone mold rubber and they each have different properties. As you can see in this picture, we use three types of rubber: purple, green and yellow.

Yeah, I know it's more of a teal or a turquoise or soa foam... I'm a guy working with chemicals and power tools. Right now, I'm just going to call it "green."

Each of these is slightly different. The yellow is made by a major company called Alumilite. We use their Quick Set Mold Silicone which sets in about half an hour (and completely solidifies in 4 hours). This is a good, fairly stiff rubber that is good for holding details and is justly famous for its long-life and durability. It's a bit expensive (the boardwalk mold had 410 grams of rubber and cost about $20 to make). That might not sound like much, but when you consider we've got 40+ molds... well, it adds up. We also have to be careful of that stiffness, as it can make it harder to de-mold smaller parts.

A look at the pump and the pot (vacuum chamber)

The Green is the 2125 from MPK Enterprises. The company is run by a guy by the name of Mike, and he's one of the nicest and most helpful guys out there. You can reach him through his site at www.hobbysilicone.com. This particular silicone rubber is very flexible which makes it ideal for small parts like the awning posts you can see in the photo above. It also has the advantage of holding details very well. In addition to small pieces, we use it for some of the roofs, as the flexibility makes it easy to de-mold the large flat panels. Finally, it only runs about $10 a pound, so it's less expensive than the Alumilite. 

The purple is the pleased spiritualist -- er, I mean "happy medium" between the two. We use MPK's Extra-Firm 135 because it's more flexibile than the Alumilite, but more rugged than the green. If I had to pick just one rubber to use for all occasions, I would choose the purple. Fortunately, I don't have to pick just one. As with any job, you need to use the right tool for the task at hand. Figuring out which rubber matches which mold master is a bit of an art, but I'm getting better at it.

Just as there are different molds for different situations, we use different resins for different applications. Come back next week and we'll talk more about why sometimes we use white resin and sometimes we use tan.

See ya then, amigos!

Arnica: Making a Replacement Mold

In case you didn't know, Hawgleg Publishing also manufactures and sells resin buildings to use while playing Gutshot. We sell these buildings under the name Arnica Real Estate (we inherited the name when we bought the Arnica line of buildings from Mark McGraw a few years aback). You can see the complete line of buildings over at www.arnicarealestate.com.

Right now we're only offering buildings from our Western Collection: http://www.arnicarealestate.com/cart_catHome.asp?ppcID=1  But I hope to start making some molds for the Adobe Collection later this week. Mosey on by the site to check out what we've got ready and what's next on the list.

Making buildings takes a lot of time and energy, as well as some specialized equipment. This week we launched a new Spring Reopening, so I'm working to fill orders and to replace some molds that have been damaged over the last year. One of the most important molds (at least in terms of sales) is for the boardwalks. There are three to a pack and, up until now, I've been operating with just two molds, and one of them actually tore across the bottom but is still usable. But, the truth is, it's gotten a bit rough and it needs to be retired. So, I need to make a new mold that will let me pour two boardwalks at a time (and with the other good Boardwalk mold I still have, I'll finally be able to pour a whole set at a single time).


Here's a quick photo strip of what I did tonight while making a new mold for the Boardwalks:

Two resin masters glued to a board.

First I prepped the masters. They were already attached to the masonite board, so all I had to do was seal the edges.

You see, if there are any gaps between the resin master and the board, the rubber will seep into it and make it very hard to pull off the mold rubber after it solidifies.

Painters Tape seals it, the walls add structure.

The next thing I did was build a mold box around the masters. Now, I'm bound to get some criticism form people for how I do this. I know most people use wooden boards and either clay or epoxy to create the walls around the masters. That's not how I ride, pilgrim.

I use 3-inch wide painters masking tape to adhere 1-inch thick Styrofoam blocks around the masters. These form the box walls.

I use this method because the Styrofoam is light, but at this thickness won't bend or bow against the weight of the rubber once the box is full. The painters tape forms a perfect rubber-tight seal (I use special corner joints to make sure there are no gaps at those crucial points).

Be careful to brush into the wood grain.

Once the box is built, I then heat Petroleum Jelly in the microwave oven for about 5 minutes at 70% power. This softens it enough to make it easier to brush on.

I cannot stress the importance of this step!

It is absolutely VITAL that every tiny bit of the master is coated with a thin layer of petroleum jelly. If the layer is too thick, you'll lose the wonderful detail in the wooden planks of the boardwalk. If it's not thick enough, though, the rubber will probably tear during the de-molding step (which we'll look at on Thursday), thus wasting your work and your mold rubber.

No kitchen is complete
without a vacuum pump!

It's also important to coat the tape on the walls and the bottom of the mold. If you don't, tearing will almost certainly be in your future.

I took a picture of the next step, but you can't see it clearly enough to make it worth the effort to post it. The next step I take is to put a small 1/2 inch square wooden dowel along the edge of the box and mark a line with a pencil. I then put another one on top of that and mark again. This gives me two continuous pencil lines around the inside of the box to act as guides when I level the box after its full of rubber. I also use this line to make sure that my molds are at least a half-inch thick. Any less than that an there is a significant risk of tearing the mold as you work with it.

Next up, I get out the mold rubber (in this case, Alumilite Quick Set) and mix it according to instructions (I'll discuss this more at a later date). Then it goes into the Vacuum Chamber. This is a vital step because mixing the rubber introduces a lot of air into it. Air can lead to bubbles which can lead to ruined molds. Our Vacuum Chamber is not your typical kitchen food-saver. This is a powerful 1/3 horse power motor capable of creating a pure vacuum.

In a vacuum, no one can hear you bubble.

Once there is no air in the aluminum chamber, the mold rubber loses its surface tension, rises up about 2 inches and begins to "boil."


This is a COOL thing to watch. The thick goo looks a lot like pancake batter (with this rubber, it's particularly pancake-like because of its color and the way the bubbles pop on the surface). The bubbles keep roiling about until I finally break the vacuum and let the air back into the chamber. I actually took a video of this through the top of the chamber's clear lid. I'll post it to YouTube some time in the future.

By the way, yes that is dried resin in the bottom of the pot. I had an accident two weeks ago and the boiling resin overflowed the cup. I keep meaning to clean it up, but I keep getting sidetracked.

It must sit flat.

After the resin has been degassed, I pour it into the mold box. The painters tape ad the Styrofoam walls hold up perfectly. Sorry I don't have any photos of me actually pouring the rubber, but it's sticky and I needed both hands to get the rubber into the box. In other words, I didn't want to get sticky rubber all over my camera phone!

Also, the pencil lines I mentioned help me level the mold as it cures. This particular type of silicon rubber takes about 4 hours to cure. However, I prefer to let it set for at least 12+ hours before I consider demolding it, and I won't use it for 24-48 hours, as that helps it cure more thoroughly.

It is very important to level the mold as the silicon rubber cures (i.e. hardens). If you don't, then the mold will be lopsided and every time I pour resin into it the final items won't be flat: one side will be thicker than the other. And that, of course, just ain't how we roll. The final step is to use a vibrator (the big type for your neck or back) on the table to help it jostle loose any bubbles that might be trapped below the surface. This is just a precaution as the degassing step removed most of them. This last vibro-step is "just in case" some air got caught beneath the undercut of the edge of the boardwalk.

If you'd like to take a gander at what we're going to make with this mold, you can see (and buy) it here: http://www.arnicarealestate.com/cart_detail.asp?ppID=22


See ya Thursday for the demolding, and the first pour!