vince’s ear

Making a cast of an object such as a sculpture is easy as long as you have the right materials. It took some product testing and trial and error but I do believe I’ve found some decent mold making and casting supplies.

Hobbies, Crafts, or Small Business

There are any number of reasons you may want to make a mold of something: you may simply want a copy of a keepsake; a duplicate of a tool or other useful object; some molds for soap, candle, or candy making, or you may have another crafty purpose such as making chess sets, as was the reason for my pursuit. Many people sell their handmade crafts on sites such as Etsy.com.

I started sculpting as well as turning chess pieces a little while back when I got my mini lathe (Turning Chess Pieces 101). As an amateur turner I can turn a decent piece and even duplicate one fairly close to the original, but chess pieces can’t be close; they need to be exact. So I needed to find a way to cast the original many times over for accurate copies. This would also make it easier in the long run- I’d only need to make 6 pieces on the lathe.

Finding The Perfect Material

Like an engineer, I needed to find the best and least expensive material for the project. Other factors are considered such as time and effort, re-usability, and difficulty. As you can see in the pic above I went through a fair amount of products to find the right stuff, and it was by no means cheap. But you have to crack a few eggs…

I rated the materials from 1 to 5 stars for several categories: 1 being the worst, as in a “1″ for time means it takes a long time, a “5″ for difficulty level means it’s easy, etc.

The Casts

1. Permastone- By and large this is the material I was most pleased with. This is a stone-like plaster which mixes with water 3:1 and dries quickly to give you a smooth, heavy cast which retains minute detail.

Quality: *****

Re-usability: ****; nice and durable finished product

Difficulty level: *****

Time: ***; 1-2 minutes mix, about 15-20 minutes for a solid cast

Price: ****; About $5 for 28 oz. box

2. Castin’ Craft Casting Resin- Ack! Don’t get any on your hands, this stuff is beyond sticky. You have to mix a catalyst just right or the resin won’t cure properly. It took three days before it even began hardening. In the end, the clear plastic finished product has potential- a good substitute for glass chess pieces, but using this resin doesn’t seem practical.

Quality: ***; the piece doesn’t look too bad

Re-usability: ***; solid and durable, but a week later the bottom is still sticky

Difficulty level: **; the stickiness and the mixing make it difficult to work with

Time: *

Price: **; Something like $12 to $15 for 16 oz., catalyst sold separately for some reason (?)

The Molds

1. Castin’ Craft Mold Builder- Very nice liquid latex mold builder, good for making molds of small, detailed objects, preferably flat, but not suited for my purposes here. The liquid is brushed on (no mixing reguired), and captures the finest detail. Depending on the size of the original, many layers may need to be applied. I made a cast of penny with the Permastone- every detail was preserved and the cast popped right out.

Quality: ****

Re-usability: ***; if only a few layers were applied, the latex is fairly flimsy and warps a little

Difficulty: *****; only setback is the washing of the brush in between each coat

Time: ***; each layer must dry completely before applying another. This may take some time if it’s a large object and needs 10 + coats

Price: ****; About $7, enough latex for many small molds.

3. Alumilite Quick Set Silicone- Now here’s where I need to make a managerial decision. Is the excellent quality of the mold worth the 4 hour wait? Silicone is the main material I sought on my shopping quest, I even bought some silicone caulking tubes to try out later as a cheap alternative. A catalyst is needed to mix, but isn’t very difficult, and this one comes with measuring cups which is a major plus (I had to weigh the casting resin earlier). One thing is for sure- the mold itself is probably the most durable, so even if it takes 4 hours at first, I should be able to get many uses out of each mold.

Quality: *****

Re-usability: *****

Difficulty: ***

Time: **

Price: *; $35 for 14 oz., just enough for a couple molds.

4. Webster Group 3D Gel- I certainly found treasure with this one, hidden amongst the little kiddie clays and molds. I think I have a winner: it was $4 for this packet (1 large mold and one small mold, $15 for a larger container), it took about 2 minutes to mix and2 minutes to completely harden (need to work fast), and the quality of the mold seems about the same as the Alumilite silicone- should be able to get many molds out of this. Plus, all I had to do is mix 3/4 cup of water.

[Update: Unfortunately after about a week, the mold dried up, reduced in size about 1/3, and became brittle. Looks like this is a great one time mold, but nothing more.]

Quality: *****

Re-usability: *

Difficulty: *****

Time: *****

Price: ****; $15 container ought to yield a decent amount of molds

5. Amazing Mold Putty- Another treasure found in the kids section. It shows a baby on the front so the store must have thought babies are supposed to play with it. But they didn’t notice the picture actually shows a mold being made from the baby’s hand. Very professional product, and very easy- 2 tubes of A and B, mix equal parts, knead until uniform, then embed an object, sets in 20- 25 minutes. When hardened, it made an excellent and durable mold. The only problem was a crease which came when I wrapped the putty around the chess piece. Instructions didn’t say youcould wrap, but I think I can find a way around this.

Quality: ****; we’ll see if the creases persist

Re-usability: *****

Difficulty: ****; 4 stars only because it is super durable, and for my purposes harder to make the cut line to get the piece out. Depending on how you look at this, the extra good quality makes up for it.

Time: ****

Price: ****

6. Instamold is made by the same people as Permastone. It is mixed with either 1 to 1 powder and water for a strong mold, 1 to 2 for average, and 1 to 3 for a weak mold. It appears that the 1 to 3 may save money, stretching the amount of molds possible from one box. I used the 1 to 2 average mix. I don’t know if it was because of the mix ratio, but this material was extremely bubbly. Luckily, only one minor defect resulted on the piece, which was easily sanded away. The set time for this was very quick- about 10- 15 minutes. However, while easy to cut away the original, it ripped a little.

Quality: ****; made a good piece, a little weary of the bubbles though

Re-usability: *; When I opened it up, it tore, and while I could be a little more careful, I’m doubtful the mold can be used more than a few times. [Update: After about a week, the mold dries up and shrinks.]

Difficulty: *****; easy mix, easy set, easy release

Time: *****

Price: *****

7. Sculpey, and generic modeling clay- Before I went shopping for the real mold supplies, I made a mold of a chess piece with Sculpey clay. This clay never hardens until you bake it, so is ideal for making a cheap one-time mold, which you can demolish and use for any other clay sculpting. The material is very pliable so makes for easy original removal, but difficulty in resealing the mold for the pour. In the end, an interesting duplicate is made, but nothing that can be sellable. A first attempt at chess piece mold making.

I also tried some modeling clay just in case I can make the absolute cheapest option work in any reasonable way. As I imagined the molds did not capture any real detail and crumbled the first time I removed them after the cast was dry. The clay molds of the smallest pawn pieces (about 3/4″ tall) actually turned out better than the Sculpey ones, which utterly failed beyond recognition.

Quality: **

Re-usability: *

Difficulty: *****

Time: *****

Price: *** for Sculpey, ***** for Modeling clay

The Results

 [From left to right: Instamold small queen, 3D Gel rook and pawn, Amazing Mold Putty bishop and pawn, Pawn made from Clear Casting Resin set in Sculpey, 2 small pawns set in modeling clay, 2 small pawns set in Sculpey, 2 large pawns set in Sculpey]

After this trial and error I have no reason to look for a further casting material: Permastone duplicates every detail, makes a heavy chess piece, and can be mixed with paint and other debris for effects. Some of the smaller ones in the picture above have been swirled with magenta watercolor paint for a “marble” look.

The Amazing mold putty is a very good product. However, the nature of the 3 dimensional chess pieces probably requires something which can be poured over the pieces. I will attempt to perfect the wrapping of the putty- aside from the crease it does make a good duplicate, and the mold seems to be infinitely re-usable.

In the end, the Alumilite 2-part silicone is the winner. The 3D Gel would have been great if only the mold lasted. If you only need to make a single duplicate, I’d recommend the 3D Gel, but if you need a mold which will last, the silicone is the best bet.