After coming across the idea in a wonderful book of nature activities I picked up from a charity shop, I’ve been eager to try out making an animal track cast out of Plaster of Paris of some of those tracks we find out on our family walks. We gave it a first shot this winter when the deer were crowding around in the local fields but the chilly temperatures meant the plaster took too long to set and in the end we had to abandon our efforts, bringing home a lump of crumbly, clay ridden plaster dust rather than the beautiful track print we had intended!
Last week we gave it another shot. Having learnt from our previous mistakes we gave it plenty of time this time, the weather was warmer and we came armed with a trowel so we could dig underneath the cast into the clay that stuck so fiercely to our last attempt.
Despite still being fairly stone-riddled, the result was much more successful! We came home with a fairly clear cast of a Roe deer track and once we had dusted off the dried out mud and cleaned it up a bit, it wasn’t a bad first effort, though there’s loads of room for improvement.
Whilst the waiting time involved and the care needed with plaster of paris means that this is a tricky activity for toddlers and Beth wasn’t that excited by the whole thing, Roo at four and a half had a brilliant time helping me to take the cast. She has asked to go again soon so I have a feeling that the huge bag of plaster of paris I bought in haste is probably going to get used up after all!
Once we get really proficient at casting tracks I will put together a little You Tube video. For now though, if you fancy a go yourself, then this is how we set about making or first successful animal track cast.
What you need:
- Plaster of Paris (you can get this easily online or from a hobby/craft store.
- A bottle of water
- More water to rinse fingers with or a pack of wet wipes.
- A mixing container you don’t mind throwing away (this could be something like a large old yoghurt pot, ice cream container or even a large sandwich bag)
- Some bendable card and some paper clips (optional)
- Scissors (optional)
- A trowel (optional)
- An old spoon (optional)
- Some cardboard, bubble wrap or something else to support and protect your cast on the way home.
- A bag to put your cast in and one to protect your rucksack from messy plaster of paris residue on the way home.
How to make your animal track casts:
- Put all your kit into a comfy bag for carrying with you on your nature walk. Pack a spare plastic carrier bag to help protect your rucksack from any mess on the way back. A clothes peg or elastic band will come in handy for resealing your plaster of paris bag on the way back. Alternatively tip some out in to a sandwich bag or two.
- Find a track! These are easiest to find the day after wet weather (but not too soon or the ground will not be dry enough to take a good cast). Winter is a great time for finding animal tracks in mud but as we discovered, the cold increases the drying time of the plaster so be prepared to wait it out.
- Prepare your animal track for casting. Remove any large debris in the track that will obstruct the cast e.g. stones, seeds etc. You can use cardboard to bend into a circle (use paperclips to keep in place) to make a mould for your plaster of paris around the animal track. Alternatively you can use a stick or trowel to build an earth dam in a circle round it. On flat ground and working with thick plaster of paris you can get away without using a mould at all – we did!
- Mix up the plaster of paris by pouring the water into a well in the middle of the plaster. Mix well with a spoon or a clean stick. The general rule is two parts plaster of paris to one part water. You can use a spoon to measure it out or you can take a rough guess, mixing to the consistency of a thick batter. The thicker you make the plaster of paris, the less time you will have to work with it before it sets. Conversely, make it very runny and you’ll be waiting around for ages and it could escape the mould!
- Pour the plaster of paris into the track, filling first the animal track itself and then the area immediately around it.
- Rinse off fingers (plaster of paris can cause burns as it sets) and wipe down any equipment with plaster on that you want to save to use another time. It’s a nightmare to remove once it is set!
- Sit back and wait! In warm, muggy weather it took our track about 20 minutes to dry sufficiently. In cold weather expect even longer. With little children it’s best if you have some other activity planned whilst you wait or look for some more tracks to cast.
- When the plaster of paris is quite firm but still soft you can use a stick or pointed stone to write some details, such as date, animal track type etc. on the back. You can also neaten up the edges by using a knife to cut a smooth edge at this point. Next time we are going to try putting in a picture hook or bit of hooked metal into the back to use to mount our track on the wall once it is dry.
- Once hard carefully and slowly peel up the plaster cast from the ground. If you are working on very sticky ground or clay, like we were, or if you can’t wait for the cast to dry completely before heading for home, use a small trowel to carefully dig under the cast.
- Wrap up your cast in some protective cardboard and a plastic bag.
- Back home, leave the cast to dry out for 24 hours. If it still has mud on it, you can leave this to dry overnight before brushing it off with a paint brush. You can gently sponge off any extra dirt too with cool water – just don’t completely soak your cast or you risk damaging it!