View Full Version : Best Material For Casting Tracks?
I want to start a collection of animal tracks, via making a plaster cast of each track and then somehow ( ideas? ) transferring same track to something a little more longterm?
My initial thought was some metal material but the process for transferring one track ( plaster ) to the other ( metal ) must retain detail and provide a long term 'tactile' substance that can be picked up . touched etc .
Ideas?
what about having a look around a dental supply web sites such as the dental directory, things like Coltoflax Impression Putty, i've no experiance of this just an idea.
google modeling suppliers......they should be able to supply....
rubberized moulding kits or materials...
white metal moulding kits or materials....
you may find enough information on these processes to make your own kit cheaply...
Hope that's helpfull.
Minotaur
27-03-2009, 21:32
I wonder how the US CSI people do tire tracks, and footprints?
They are bound to have it down to a fine art, and they must do it more than anyone else. It is part of their job.
You could try using wax to make your first mould of the track, take it home or even out in the field once dry cover it with plaster of paris to create a positive mould. Melt the wax out using a safe heat source. and there you have a perfect copy of the track.
As per Smoggy, try a two Pak silicon moulding solution. You can get this stuff in varying degrees of hardness and cure time.
I do casting. I get my mold material from this company:
http://www.smooth-on.com/
I use dental lab stone for my castings.
Harmony
forestwalker
28-03-2009, 06:01
I wonder how the US CSI people do tire tracks, and footprints?
They are bound to have it down to a fine art, and they must do it more than anyone else. It is part of their job.
My forensics textbooks are at work, but the amazon "search inside" of Jackson & Jackson talks about plaster of Paris or dental stone. Spraying the track with hairspray apparently preserves fine details before a thin slurry is poured into the track. Langford points out that dental stone is the prefered material these days, being more durable. In particular Lanford give step-by-step instructions for the dental stone version (see URLs below).
http://www.amazon.co.uk/gp/reader/0131998803/ref=sib_rdr_next3_ex103?ie=UTF 8&keywords=footprint&p=S03P&twc=3&checkSum=aGefbiH9CCFpmm2MAGYG0 wOac308EvS7UgZk0KrS3vY%3D#read er-page
http://www.amazon.co.uk/gp/reader/0131144006/ref=sib_rdr_prev2_ex148?ie=UTF 8&keywords=plaster&p=S04O&twc=2&checkSum=ZppRVfzWDMenR81FVoPI5 ZGqid6Rxis9QXZcGh%2Fz2EA%3D#re ader-page
Googling dental stone gave several hits, e.g. http://www.evidentcrimescene.com/cata/cast/dscasting.html, with nice instructions
What about trying liquid masking fluid which artists use, it should be good for getting in the smaller detail. The finished mould would be rubbery which could be useful.
Im going to take onboard everything thats bee offered, all good advice.
Keen to see if the hairspray trick keeps the track in greater detail when casting.
Also like the wax concept for creating a 'true' track and then reverse it to make another 'negative' track.
Ideally i was thinking about casting it in something a little more suitable for display prurpose but also hardwearing enough to create 'fresh ' prints for kids etc.
Is Bronze to ambitious?
Lead is easy to smelt and soft but longevity would be an issue?
You're getting heavily into the realms of forge working if you are contemplating casting in bronze etc......can be done yes and would probably be capable of reproducing the detail you seek.....
But I think you will probably be best doing some net research into the whole subject of casting, starting with a google or two....there are some very good sites out there and its a big subjectin it's own rights...
No disrespect to anyone on this forum but you probably need to be asking elswhere, I have some knowledge of casting and metalurgy but nowhere near enough to cover all the questions your going to be asking next...LOL
Having said that, soemone is going to come allong now and astound us with his or her knowledge gained from 25yrs in the industry....LOL
Smoggy.
Singeblister
29-03-2009, 00:06
I would suggest you read up on casting mate , it can be very dangerous , if you have any moisture in your mold when you pour any molten metal into it can will spit and spray out almost like an explosion, couple of tips I can give you are if doing lost wax casting leave your plaster mold in the oven for at least 30 mins and pour the metal into the hot mold, start off with some of the low melt metals and avoid reclaimed lead, Alu is a pos and easy to get hold of if you dont want to spend much , best advice is to do lots of reading google will throw up loads of sites on the subject
Again thanks for saving me before I incinerate myself.
I am fortunate / unfortunate ( depends on what day of the a week you meet me ) to work in a an Aviation Maintenance environment , Aluminium is plentiful and the off cuts ( which are no longer of use for anything else ) would be free.
We have , as you may imagine , a wacking great big Workshop with an obscene amount of hardware and machinery , one of which is an industrial sized digitally controlled oven the size of a Volvo , me thinks i may be able to make this whole casting thing easier then i expected.
Will have to chat up a workshop supervisor or two and see what they say.
Singeblister
29-03-2009, 21:20
well it sure makes things better when you have the right gear to hand :) good luck with the project hope to see some pics soon,