by Jo Craemer

see also the article LEGAL OPTIONS FOR OBTAINING SPECIMENS by Jo Craemer

Woodcarver Ezine
Back Issues
Carvers' Companion Gateway


The first step in designing a carving is gathering good reference material. Photographs, study skins and taxidermy mounted birds are useful, but have their limitations. I've seen really nicely executed waterfowl carvings ruined by undersized bills that the artist faithfully reproduced from measurements made of a mounted bird. Many people don't realize that bills and beaks start to dry and shrink soon after the bird has died - rapidly in the hot sun if you find a road killed bird, and drastically in freeze dried or older mounts.

Commercially made study bills are available, and most are good, but you may have difficulty locating the species you want or you may want to see the details of structures inside the open bill. It's very simple to make your own.


For your own personal reference, a collection of study bills made from Dental Stone is quite adequate. The castings are durable and strong.

If you want to make multiple copies (if you are teaching a class, for example, and want to provide each student with a casting) you can use your Dental Stone cast as a "Master" to make a more durable latex or RTV mold for multiple resin castings.

I'm limiting instructions in this article to making molds and castings from the actual bird, using Dental Impression materials and Dental Stone for casts. These can be made very quickly at home or in the field. A list of suppliers will be provided at the end of this article.

materials needed<>


I use an Alginate Impression material. (Jeltrate or Surgident are two brand names.) This is the stuff you bite into at the dentist's office when you are being fitted for dentures. There are two types: Type I is FAST set and sets too quickly to be practical. Type II is NORMAL set and is easier to use.

This stuff is great for birds because it is not affected by blood or water, and does not stick to the feathers (which would ruin the bird for further reference purposes.)


I use dental plaster. It is very hard and picks up the smallest details. (I've been told you can also use #1 molding plaster, which is available from hardware stores.) DAMS & ENCLOSURES:

You'll need something to pour the Alginate mold material into. It needs to be big enough to allow at least a third to half-inch of Alginate material between the bird bill and the container. I use paper cups, small paper boxes or aluminum foil shaped around any convenient form, such as a pill bottle or the bottom of a soft drink can. The enclosure material should be flexible enough to be peeled away from the Alginate mold after it sets up. VIBRATOR:

Using a vibrator, held against the side of the Dam or Enclosure will "liquefy" the plaster. The plaster will then flow into all the crevices of the mold and air bubbles will be floated to the surface while the plaster is being poured into it. An inexpensive vibrator from the drug store works best, but you could try using the vibration from an orbital sander.

If you're working in the field, you can place the Alginate mold in a plastic bag (avoid squashing it) and wait until you get home to pour the plaster. It'll keep for a couple of hours if it doesn't dry out. Or pour the plaster in the field, tapping the mold with your fingers to try to work the plaster well down into the mold.


If you're making up a "kit" for your car, a small leak-proof bottle can be carried with you. At home, I use ice water to slow down the setting speed of the Alginate.

Have the container or dam ready to receive the Alginate impression material (Jeltrate).

Wipe any dirt or blood from the bird's bill. It should be dry. (No mold release material is necessary when using Alginate.)

Following package instructions, mix the Jeltrate in a paper cup, making enough to almost fill your dam. The brands I use need equal amounts of powder and water, a 1:1 mix. Add the Jeltrate to the water. Cold water retards setting; warmer water hastens it. To produce a creamy texture, mix with a tongue blade or plastic knife for one minute.

Immediately pour the Jeltrate mixture into your container. Working quickly, gently insert the bird's beak or bill into the Jeltrate. I try to have a container large enough to allow the head to sink at least as deep as the eyes. This gives you a permanent reference distance from the eye to the tip of the bill and to the corner of the mouth.

Now, the hard part. You must hold the bird's head perfectly still until the Jeltrate has set up and lost its surface stickiness. I can guarantee this will be the longest two or three minutes of your day. Once the surface of the Jeltrate is no longer sticky, you can gently rock the head to loosen it and carefully pull it from the mold. If any bits of Jeltrate have stuck to the feathers, and you are keeping the bird for further reference, try to remove them now.

Straight bills are easy to remove without damaging the mold. Hooked beaks (hawks) are more difficult, and you may have to make several molds before you can ease the bill out without tearing the Jeltrate. Practice makes it easier. Patience and tranquilizers help too.


Follow the instructions that come with your brand. Use a clean disposable container. Always add the plaster to the water. Never pour water over the plaster. Use cold or cool water to slow down the setting time long enough for you to work the plaster into all the small mold cracks and crevices. Using a clean tongue blade (or whatever else is convenient and disposable), mix the water and plaster for 30 to 60 seconds, stirring about two times a second. It'll set up all of a sudden, so you'll need to pour it into the mold immediately.

(Hint: Don't wash plaster dust or left-over plaster down the drain - it'll solidify in your plumbing.)

The best way to ensure that the plaster fills the mold evenly is to hold the mold on a vibrating surface while you spoon or pour in the plaster. The vibration causes the plaster to liquefy and flow evenly, and will bring bubbles to the surface.


If the bill is long and pointed or hooked, I also try to encourage the plaster to fill the very tip of the bill by gently dipping a thin, soft paintbrush tip into the plaster (still holding the mold on the vibrator) and down to the tip of the bill. Don't damage the mold doing this, and wash the brush immediately or it'll be ruined when the plaster sets. If you don't do this you may find that a stubborn bubble of air remains at the tip of the bill. Another technique is to GENTLY squeeze the mold a little it as you hold it on the vibrator.

Let the plaster set-up and harden according to package instructions. The Dental Stone that I use takes about 10 minutes.


Jeltrate molds are usually good for only one casting. If it's a simple straight bill, and you can pull it out without damaging the mold, you may be able to make one or two more casts.

Unmold the straight bills by gently wiggling the mold material to loosen it, and pull the bill out. For larger or hooked bills, I recommend carefully cutting the Jeltrate away from the bill. Use a sharp knife, take your time and remove just a little at a time. Be careful not to cut into the bill or to cut off the bill tip.

Be gentle. The plaster has not yet reached its full strength and you don't want to snap the tip off.


The plaster will be warm at first as the chemical reaction takes place. Then it will feel cool as the moisture evaporates. When it dries completely, use the flat back area to write the bird's species, sex, age (nestling, juvenile, adult) and any other information you desire - such as weight, length, etc.


You can get the Alginate Impression Material and Dental Stone from the same place your dentist buys it. I order from:

Dental Laboratory Discount Supply
(call them at 1-800-243-4571 and ask for their catalog.)

Another source is:

Hide and Beak Taxidermy and Supply Company

Call and ask for their catalog. They also offer an excellent manual, "Make your Own," a how-to reference for making molds. The catalog is full of other wonderful goodies, such as highly detailed rubber lizards and frogs - great reference material.