Helpful Tips and Articles

I will be updating this section regularly with new tips as they are discovered or when I see common mistakes that can be helped with reminders. Most of these tips below are not included in my book "Portrait Sculpture Simplified" (version 1.0).

Tips:

Modeling tips

Armature tips
Moldmaking tips
Casting tips
Patina tips
Photography and Presentation tips

Articles and External Instruction Links:

Polytek's casting and moldmaking tips

Smooth-On's how to page

Sculpt Nouveau's patina instruction book

Sculpt.com's casting and moldmaking tutorials

Aluminite's how-to moldmaking page

Bronze casting process overview 

 

Modeling tips

1. WED Clay: I recently discovered this modeling clay from Laguna Clay company that is used by many special effects movie studios. Official name: EM-217. This is an incredibly smooth and creamy water based clay that also contains retardants that slow the drying time considerably and prevent the shrinking and cracking problems that are so common with regular water based clays. The WED clay should never be fired and is an excellent and cost effective (about $13 for a 50 pound box) product for large sculpture instead of using regular ceramic or plasteline clays. Since the piece will not be fired, complex armatures can be used inside and since this is mostly water based, it will stiffen slightly, giving the piece added support. The clay can be sealed while still wet with Krylon Crystal Clear plus an additional coat of Krylon Matte Clear to dull the shine. Once sealed, the piece can be easily molded without problems of condensation (this is best done in temperatures below 75 degrees to assure there is no sweating of the clay while molding).

2. Wax Positives: If you want to make a one of a kind small bronze without having to make a mold, you can make the original in a medium -soft wax and give that to the foundry for casting. The drawback is that they only have one shot at getting it right. If the first casting does not come out well, there is no mold to make another wax positive.

3. To initially dry out a ceramic piece naturally and evenly, put it in a plastic garbage bag (tied very loosely) and place it in direct sunlight (one advantage of living in Arizona - no shortage of sunlight). Don't do this without the bag or the piece will crack.

4. To achieve a smooth surface, if desired,  apply sparingly with a brush the following: water based clays - water, oil based clays - mineral spirits, polymer clays - lighter fluid. After water based clay is fired or polymer clay is baked, you can further smooth and polish the surface with fine sandpaper and steel wool. 

5. When you think you've finished modeling a piece (or at any time in the process), look at it in a mirror. You will be surprised at what you did not see beforehand.

6. With figure sculpture, always make heads and hands detachable so you can work on them apart from the main figure. Heads and hands usually require much more detail and should be freely rotated while modeling them to observe all angles.

7. Children's heads are nearly as big as adult heads. It's their bodies that are proportionally so much smaller. Don't make the mistake of making an adult figure with a child that has a doll head.

8. Eyes are NOT flat! Remember, there are actual balls in those sockets.

Armature tips

1. Be sure your armature is strong enough to support the amount of clay that you will be adding when working with plasteline clay. Nothing worse than having a piece bend and slump half way through the project.

2. If possible, build an armature with detachable head and hands. Pipes that screw or pin together is one suggestion. Wires can be clamped.

3. One way to make a large or life-size armature - basic overview: 

   1. First, plan the structure of the armature and draw a detailed illustration of how the armature needs to be constructed inside of your figure, depending on the pose.

   2. Start with a large board that is mounted on a platform with wheels or dollies. 

   3. Build the core out of galvanized pipe running through the main sections of the sculpture, using T's and elbows for making turns. An additional section may need to be attached on the back to support the main frame. These pipes are screwed to the board using flanges. 

   4. Use heavy gauge aluminum wire through T's in appropriate places to add extremities and bend them in place. 

   5. Cut pieces of Styrofoam to fill the large voids of the sculpture  and duct tape them to the figure's pipe armature. You can use rasps to shape the Styrofoam.

   6. Cover the entire figure section with aluminum foil to hold the Styrofoam and keep the little balls from coming off everywhere, making a mess.

   7. Wrap the entire armature in a spiral manner with thin, twisted wire. This gives the clay something to hold on to. 

   8. Cover the armature with a thin layer of plasteline clay. This is easier if the clay has been warmed in a light box or microwave. You now have a fairly light, yet strong armature with which you can continue to build out your piece in clay.

Moldmaking tips

1. Using Plaster: Plaster and hydrocal are good materials for making decent and inexpensive mother molds. Though heavier than the more expensive resin and fiberglass products such as Smooth-on "Plasti-Paste", they can be reinforced with strips of burlap dipped in a runny mixture of plaster and water. To apply the plaster (or hydrocal), put several quarts of plaster in a bowl and quickly mix in enough water (with a gloved hand) until the plaster is the consistency of cake frosting. Stir well and squeeze any lumps with your hand. Immediately use a spatula to spread the plaster over your rubber mold (which has been sprayed with a mold release if you have not used silicone rubber). You will have about 15-20 minutes of working time before the plaster is too stiff to work.

2. Dishwashing liquid (Dawn, Joy, etc.) works well as a barrier for separating silicone molds where the sections of the rubber meet. Just brush it on undiluted where you want the rubber to separate, let it dry, then paint on fresh rubber for the next section.

3. Large pieces need to have a thicker rubber mold made (at least 1/2 inch thick) than you would make for a smaller mold - otherwise, the rubber will be floppy in the mold and your resulting casting will come out distorted.

4. You can bolt the sections of your mother mold together to be sure they are secure and don't shift while casting. Just make the edges fairly thick and when dry, drill holes through both edges of the mold. When you put the mold together for casting, line up the holes and run bolts through, securing them tightly at both ends. Bolts can be used in place of, or in addition to tire tube straps or clothesline cord wrapped around the entire mold.

5. Polytek's Polygel 40/50 is an excellent urethane rubber to use for mold making. It is easy to apply, doesn't need a thickener, mixes in a 1-1 ratio by volume, and is less expensive than silicone rubber. Be SURE to use a liberal amount of the proper mold release (Pol-Ease 2300) and brush it around to every nook and cranny when casting polyurethanes or the mold and casting will fuse. Learned that lesson the hard way - not a pretty picture. To apply, brush on Polygel 40 for the first two coats, mix the 40 and 50 to use for the third coat, and use Polygel 50 for the fourth coat. Don't apply the 50 to the 40 layer without the mixed layer in between.

6. You can mix Poly-Fiber II with your outer layers of urethane rubber to strengthen and thicken/stiffen the outer portion. This also allows you to build up undercuts quickly without the rubber running off. You can also use Cab-O-Sil, but Poly-Fiber is  recommended since it will make the rubber stronger where the Cab-O-Sil makes it slightly weaker. Either fiber material can also be mixed into polyurethane resins for lay up casting.

7. To fill out undercuts, embed pieces of dry, squishy sponge between the layers of rubber to build out the areas. This leaves the undercut areas flexible while still providing support for the mothermold.

8. Always wear rubber gloves and long sleeve (grungy) shirts in well ventilated areas. Respirators are advisable. Moldmaking and casting are messy processes and most of the materials used are skin and lung irritants.

Casting tips

1. Forton MG: Forton is an architectural casting medium that is gaining in popularity among artists. This is a gypsum and resin material that is many times stronger and much lighter than plaster. Filler materials (such as bronze powder) can be added to the top coat to make very nice cold cast pieces which will take cold patinas just like real bronze. A thin layer of Forton reinforced with glass fibers is slush cast in the interior to make a hollow piece. You can read more about Forton at http://www.artmolds.com/gateway/technique/forton_1.htm I buy the big sculptors kit at Ball Consulting. Aluminum sulfate is used as an accelerator for the slush-cast layer and is usually available where you purchase a Forton kit.

2. Polytek's Easyflow 60 is an easy to use 2-part polyurethane resin that mixes 1-1 by volume. Various fillers can be added (metal powders, porcelain powder, marble dust, etc) to create a variety of castings. The Easyflow 60 is white after the chemical reaction occurs ( does not yellow) and they also have a clear version available. The material can be filed, sanded, and drilled after casting.

3. MagicSculp can be ordered in a variety of colors from sculpt.com. This is a two part resin putty that when kneaded together, invoke a chemical reaction that will turn the stuff hard as rock in about an hour. Until then, you have time to model the putty as needed so only mix what you can model in that amount of time. When you first mix it, it is sticky, so wait about 10 or 15 minutes before you use it. This material bonds with resin and other castings and can be smoothed and cleaned up with plain water. It is ideal for doing repair on castings of any type. It can be painted, tooled, and sanded once it has cured.

Patina tips

1. If you are making bonded metal sculpture and plan to apply a reactive patina to the metal, silicone mold releases will interfere with that reaction. Solutions are to either use a silicone mold that requires no release, or thoroughly wash your castings to remove all silicone spray residue before applying the patina. Another option is to dust the inside of the mold (after applying the silicone spray) with aluminum trihydrate and the piece will be "paint" ready right out of the mold.

2. Always wear rubber gloves and long sleeve (grungy) shirts in well ventilated areas. Respirators are advisable. Most of the materials used for patination are irritating to the skin and lungs.

3. If you use colored waxes, keep them air tight or they will dry out. If you have some that have dried out, buy some clear wax and mix one or more of the colored dried waxes as needed. You can buy an 8oz jar of white wax and mix just a tad of the dried (or fresh) color waxes with blobs of the white to create a variety of lighter colors which are perfect for stippling on bronze or bonded bronze.

Photography and Presentation tips

1. Do not photograph your artwork against a distracting background or a wrinkly sheet. For the best results, invest in a paper roll. These are simple and fairly inexpensive and paper rolls can be ordered in a variety of colors. One suggestion to purchase a paper system is from B&H photo.

2. When using a paper roll on a table, be sure to lay the paper flat on the table and set the support stands back far enough that the paper does not angle up to the roll directly behind the piece you are photographing. If the paper angles sharply up instead of back and then up, you will have distracting shadows behind your piece.

3. Whether you are now, or hope to become a professional artist, and desire a web presence if you don't already have one, hire a professional to make or redesign your website. If you lack the know-how to make a quality site and end up producing one that is poorly designed (e.g, impossible to navigate, full of broken links and missing images, blinding and inconsistent color schemes, annoying flashing graphics or sounds, etc.) -  or go with an amateurish site from a free website provider, that will only detract from your work (no matter how good it is) and will turn people off. They will judge your work based on the quality of your website and exit just as fast as they possibly can - that is not your goal. Providing an easy to navigate, informative, and visually pleasing website will make you appear more capable and professional and may keep people there long enough to consider buying what you are offering.