Plaster Casts

Search  Inquiry Net

[ Back ] [ Home ] [ Up ] [ Next ]

Activities
Archery
Axe, Boy Scout
Axe, Saw, Forestry
Axe, Saw,  Knife
Axe Use: Beard
Axe Use: Seton
Axe Use: Traditional
Axe Throwing
Beds, Woodcraft
Bedding Materials
Bicycle Maintenance
Birch-Bark Torch
Birds
Bird Houses
Blocks Tackles Purchase
Blood Red Cross
Broom: Camp or Witch's
Buttons
Campcraft
Camp Hygiene
Camp Planning
Campfire Programs
Catapult
Chainsaws
Checklists
Chuck Box Riddance!
City-Craft
Compass Bear Song
Compass, Home-Made
Cooking
Cotton Kills Bear Song
Deduction in Tracking
Deduction & Detective
Drum
Dyes
Edible Plants
Equipment, Leader
Equipment, Personal
Equipment Maintenance
Equipment, Lightweight
Equip, Pickle Bucket Camp
Estimation
Field Signals
Fire-Building
Fire Building
Fire Laying
Fire Lighting
Fire Starters
Fire: Rubbing-Stick
Fire Types, Wood Types
Fire Council Ring
Fires: Woodcraft
First Aid
First Class Journey
Flint & Steel
Flowers
Forest
Gesture Signals
Ground to Air Signals
Handicraft Stunts
High Adventure
Hiking
Hike Planning
Indian Sundial Clock
Insect Collecting
Insect Preserve
Indian Well
Knife & Hatchet
Knots, Bends, Hitches
Knots: Diamond Hitch
Knots: Lashings
Knots: Rope Work
Knots: Seton
Knots: Traditional
Knots & Whipping
Lashings
Lashing Practice Box
Lace or Thong
Learn by Doing
Leave No Trace
Leave No Trace
Lights
Local Knowledge
Log Ladders, Notched
Log-Rolling
Logs: Cut Notch
Logs Split with Axe
Loom and Grass Mats
Lost in the Woods
Manners
Maps
Map & Compass
Maps: Without Compass
Measurement
Measurement Estimation
Menu Worksheet
Menu (Adult IOLS)
Mosquitoes
Mushrooms
Night Tracking
Observation
Old Trails
Paints
Pioneering, Basic
Pioneering Models
Plaster Casts
Preparations
Proverbs
Rake
Rope Care
Rope Making
Rope Spinning
Scout Reports
Signal & Sign
Sign Language
Silent Scout Signals
Smoke Prints
Snakes
Spanish Windlass
Spoons
Staff/Stave Making
Stalking Skills
Stalking & Observation
Stars
Stools
Story Telling
Stoves & Lanterns
Summoning Help
Sun Dial: Scientific
Survival Kit
Tarp Poles
Teepee (4 Pole)
Tent Care
Tent Pitching
Tom-Tom
Tomahawk Throwing
Tomahawk Targets
Totem Making
Totem Animals
Totem Poles
Training in Tracking
Tracks, Ground, Weather
Tracking & Trailing
Trail Following
Trail Signs & Blazes
Trail Signs of Direction
Trail Signs: Traditional
Trail Signs for Help
Trees of the NE
Wall Hangings
Watch Compass
Weather Wisdom
Wild Things

Scout Books

Site Contents

By Gillcraft

One disadvantage of the snow as a tracking medium's that it has not been found possible, as yet, to secure the cast of a track in it. This is where mud and sand have a distinct advantage.

A plaster cast gives a permanent record of any track that may have been seen. The making of plaster casts is part of the test for the new Tracking Badge for Scouts; and a collection of such casts forms an interesting exhibit in a Troop or Patrol Museum, as well as proving useful in actual tracking work, since casts can be utilized indoors to show actual reproductions of tracks in a box oaf sand.

Plaster of Paris is usually obtainable from any builder's yard. It costs only a few shillings a hundredweight, so that frequently a Scout can obtain a tin full of it for a copper or two, or less. The best plaster is that used by dentists - fine Italian plaster - but is not so easily obtainable. In any case care must be taken to see that the plaster is absolutely fresh, and that it is kept in an airtight tin, as exposure to the air will render it stale so that it does not set readily when mixed with water.

When a track has been found on the ground, carefully lift any loose material, straws, etc., that may be laying across it, but take great care not to mark the track itself in doing so.

If the track is shallow or on sloping ground, it will be necessary first of all to build a wall round the mark with twigs or mud, or even strips of cardboard, so as to keep the plaster on the track while it is in a liquid form.

In order to make the mixture, pour a quantity of water into a mug and sift the plaster into it, breaking up any lumps as much as possible. Stir all the time, and keep on adding plaster until the mixture is of the consistency of thick cream, and can just be poured out of the mug. The quantity of the mixture required will naturally vary with the size of the track, but it is better to make too much than too little. Tap the mug on the ground, or with a knife, so as to get rid of air bubbles, and pour the mixture gently into the crevices of the track. Be sure that the cast is made thick by adding successive layers of the mixture, as otherwise it will break in transit.

If the mixture is too thin, the cast will take a long time to dry, and will often be friable and easily crumble and break when it does eventually dry. If the mixture is too thick, it may set before all the interstices of the track have been properly filled.

The time the cast takes to dry will vary greatly according to atmospheric conditions and the dampness, or otherwise, of the ground itself. A pinch of salt added to the mixture usually has the effect of making the cast dry quicker, and of rendering its composition stronger.

When the cast is nearly dry, scratch on the back of it the place, date, and your name, and, if you know it, the name of the animal responsible for the track. At the same time make a record in your note book of all details in connection with the track - type of ground, weather conditions, age of track, what made it, its age, sex, etc.

When the cast is quite dry, dig it up, and wash off all the mud and earth that may still adhere to it. If you cannot wait till it is absolutely dry, dig it up and let the surrounding earth or sand adhere to it. When you have reached home it can be hardened by baking it in a slow heat, after which the superfluous earth can be brushed away. Take care, however, not to apply too fierce a heat as the cast will be apt to crumble to pieces.

Be particularly careful to wash out the mixing mug at once, after the mixture has been poured out on to the track, as otherwise what is left of the mixture will naturally harden, rendering it difficult to get the mug clean again. If the mixture has hardened in the mug, the best way to remove it is to place the mug in boiling water, so that the water does not touch the plaster, when the mug may expand sufficiently to release the plaster in a lump.

Before the plaster cast is quite set, a loop of string or wire can be inserted into it at the back so that the cast can subsequently be hung up in the Troop room. Otherwise, if casts are to be kept in good condition for any length of time, they should be stored in a flat box such as a butterfly case.

A knowledge of how to make plaster casts is a very useful accomplishment, because all kinds of things can be cast, from model bridges to leaves. In the case of leaves an impression of the particular leaf is first taken in plasticine, or some similar composition, and a cast subsequently taken of this impression in the usual way as detailed above. A surrounding wall of some kind will of course be necessary, and this wall should be shaped symmetrically, so that the cast can be used as a decorative plaque on the wall. The leaf cast can be subsequently colored with ordinary water paints.

The best plaster cast I have seen was one taken by some Australian Scouts. It shows the track of a wallaby; the marks of both the fore feet and hind feet are clearly seen, and also the mark of the tail behind the next step ahead. The cast measures a foot across, and came to Great Britain from Australia without damage.

It will be of interest, and of use, to give the Police method for taking a permanent cast of a footprint. It has the disadvantage that the mixture requires heating and takes more time to make, but it has the advantage of making the cast more permanent and less liable to fracture.

The instructions are as follows:

Heat two parts of resin to one of paraffin wax (candle grease) in a kettle or tin over a slow fire until melted. Stir well, taking care that there are no lumps of any kind left in the mixture. The composition is then ready for use and is poured into the track and lifted after it has hardened.

For an afternoon's inter-Patrol competition let each Patrol set out with a tin of plaster, mug, spoon, and bottle of water and return in a given time, with as many different casts as possible.

A very remarkable cast was found by a Birmingham Scouter in 1926. While playing tennis at a club his attention was drawn to what appeared to be a hand standing out of a stone built into a bank. A good look at the stone showed him the casts of two distinct feet standing out in relief, one foot having four toes and the other five. The stone measured fourteen inches by ten inches, and a photograph of it is reproduced. The Scouter was greatly interested, dug the stone out of the bank, and instituted inquiries in connection with it. By a process of reconstruction of events, as Huxley puts it, the following story was deduced from that small piece of stone:

Some fifteen or sixteen million years ago, when our climate was hot and damp and muggy, and when the large forests of palms and ferns that now form our coal deposits were still above ground, a large newt, which is now known by the pretty name of Ichnuim Sphaerodactylum, wandered round the edges of a muddy pond in the part of the country where Hampstead now is. He left the marks of his feet in the mud and passed on. But very shortly afterwards there was a dramatic climatic change in the world's history. The hot sun came out and dried the mud just after a shower of rain had pitted its surface. Great storms of desert sand came and covered up everything, and all vegetation, and most animal life, including our friend the Ichnuim Sphaerodactylum, died in the intense, blazing heat. During a further few millions of years the sand that had covered the tracks hardened into sandstone. Over thirty years ago, when quarrying stone for the bank of the tennis club, the very bottom layer of the sandstone was reached, and on this stone being turned up, on the underside of it were the complete casts in the sandstone of the tracks of the feet of the prehistoric newt - a reptile some five or six feet long!

Plaster casts are nothing new.

 Training in Tracking