I like using putty to help join pieces and fill gaps! It allows for stronger joints, better posing, and for some models, like Games Workshop's Tyranid Hive Tyrant. I hope to assemble some useful references here.

Materials

• Putty - I currently use:
  • Milliput putty (Standard yellow/gray should work) for building up and weighting bases. It is very hard and heavy. It cures to a rock-like consistency.
  • Kneadatite blue-white for filling gaps and more delicate work. It adheres well and is cleaner and easier to sculpt, IMO.
  • Kneadatite blue-yellow is best used for full fledged sculpting projects, although Milliput may be desirable for components that need to be rigid as blue-yellow will cure to the consistency of hard rubber.
• Putty tools
  • A double ball sculpting stylus.
  • The standard GW putty tool - with a small blade on one end and a squared rod on the other end.

Warning: I recommend that you do not use plumber-style epoxy putty. It's only about a 35% savings, it is smelly and nasty, and it will stain your hands like crazy.

Epoxy resin vs. solvent-based - there are two basic types, epoxy resin putty (ERP) or premixed solvent-based putty (SBP). ERPs are . . . epoxy resins, which means you have to mix two parts together. Once you mix two equal parts, you knead them until the color is uniform (evenly mixed) and then work into the space/shape you want. It will gradually harden and it will become less water soluble as it does. Once an ERP dries, it can be sanded, filed, drilled, tapped, etc. ERPs bond materials together well; Milliput, can even be machined after it has set. SBPs have the advantage that you simply squeeze the tube and go to town. However, an SBP is not as good for durability, adhesion, and building up features. So, if you only need to fill some cracks, you can use an SBP or ERP, but if you want to sculpt a new head, arm, weapon, etc. then use ERP.

Grain size - Putties for use in hobbies and modelling come in different grain sizes. Fine grain will be more expensive, but is better for sculpting new parts and filling fine, exposed cracks.

Handling & Storage of Epoxy Resin Putty

Generally, the good stuff will come in a two-part ribbon. Separate the two sides of the ribbon, cutting away and discarding the thin strip where the two types meet. Store them separately inside the freezer. This will dramatically increase their shelf life. Fear not, it will be ready to use almost immediately from the freezer. It will cut more cleanly because it is colder, and will warm up almost immediately as you knead the two parts together.

Applications

• fill gaps in models
• create additions and modifications
• make your own figure

Brands

1. [ERP] Kneadatite Blue-White (Manufacturer Info) - good gap-filler on mins
2. [ERP] Milliput (The Milliput Company) - dries hard, can be machined; available in Standard Yellow/Grey, Silver Grey, Superfine White, and Terra-cotta
3. [SBP] Kneadatite Blue-Yellow (Manufacturer info) - AKA"green stuff" to minis enthusiasts; the industry standard for minis sculpting
4. [SBP] Squadron Putty - AKA"green stuff" to plastic model kits enthusiasts

Note: Green Stuff is Not The Same Thing to Everyone

Among miniatures enthusiasts, "green stuff" refers to Kneadatite Blue-Yellow, an epoxy ribbon putty that is good for sculpting masters of miniatures, whereas among plastic model kit enthusiasts, "green stuff" is a solvent-based putty useful for filling gaps in plastic model kits.

Tips & Tricks Using Milliput ERP

See Milliput's home page and read about sculpture techniques. Most important and generally useful is pointing out that the epoxy resin putty slowly hardens and becomes gradually less water soluble. This means that you can dip your finger in water and smooth out the surface. You scan also wet your tools for easier working, but since water will not readily stick to metal putty sculpting tools, you can use a mixture of KY and water. The old school method was licking the sculpting tool, but that may not be good for your health.

When I knead the pieces together initially, there is a tendency for small particles to flake off and fall onto my work surface. That's messy and wasteful. After I break off the two pieces and initially combine them together, I dampen my fingers in by dipping them water once. This helps reduce the amount of particles that break away and fall off the ball of putty.

Stages of Milliput

• Initial - soft and tacky
• 1 hour - rubbery and less tacky
• 3-4 hours - hard and tack free
• overnight - rock hard (now it can be filed, machined, drilled, tapped, etc.

Tips & Tricks Using Green Stuff

I am a neophyte, but here are some pointers:

• Green stuff cures somewhat fast and it's consistency changes a lot from mixing to curing, play with some first to get a feel for it.
• Be sure to wet your tools as needed to prevent sticking and facilitate smoothing
• Work in layers because of the curing properties and becaue it gives you some insurance against messing up the whole thing (you can peel off a recent mistake and try again)
• If you need structure, a firm support can help, e.g. armatures
• Cool trick - for miniatures wings, make an armature of sorts out of the wall of a soda can :)
• Green stuff dries to a hard rubber consistency; if you need rock solid, you can add some Kneadatite Brown/Aluminum, or you might use Milliputt for that particular part

Groups

• 1listsculpting Yahoo! group - I highly recommend them, they are helpful and knowledgeable.

References

• Miniature Sculpting Tutorial by Ramon Laan
• Miniature Figure Sculpting by Bob Lippman
• Milliput's How To Page (follow Some Basic Techniques in Epoxy Resin Sculpture)
• The Kneadatite putties
  • Kneadatite Blue-Yellow page
  • Kneadatite Sculptor's Tips & Work
  • Kneadatite Blue-White (harder to find info on this one, this "tech sheet" is the only link)

Where Can You Buy Them?

Support your local stores if at all possible! Try to get them to carry the paints you like. If you have a "real" gamestore nearby that supports your hobby with good discounts and/or a place to play, then help keep them alive. The extra 10% you might save from mail order or online ordering will not be worth it if your local store goes out of business! That said, sometimes the store does not have what you need. Here are some vendors: