making a mold with RTV silicone rubber &urethane foam?

February 5, 2010 - 6:09 am 1 Comment

How do you make a mold of an object using urethane foam and/or RTV silicone rubber, and are there any substitutes for either one if you can’t find them?

RTV silicon rubber is usually poured, it’s fairly liquid.
You can also use 100% silicon rubber from any hardware store. Squirting it into a pan of water with plenty dishwashing liquid in there allows you to shape the silicone into patties which can be used for mold making.
But if you google RTV silicone rubber you find about a hundred place which are happy to sell it to you. Same with urethane.
But if you want to substitute, it really depends why you want to use urethane. Light weight important? If not you could use plaster or hydrocal for less fragility. Resins tend to be expensive, but for something small might be appropriate.
Wax, chocolate, concrete are all substances which can be poured and have been used for sculptures…

How you make a mold of an object depends largely on your object. You can find plenty of general instructions for mold making online.

One Response to “making a mold with RTV silicone rubber &urethane foam?”

  1. tigris Says:

    RTV silicon rubber is usually poured, it’s fairly liquid.
    You can also use 100% silicon rubber from any hardware store. Squirting it into a pan of water with plenty dishwashing liquid in there allows you to shape the silicone into patties which can be used for mold making.
    But if you google RTV silicone rubber you find about a hundred place which are happy to sell it to you. Same with urethane.
    But if you want to substitute, it really depends why you want to use urethane. Light weight important? If not you could use plaster or hydrocal for less fragility. Resins tend to be expensive, but for something small might be appropriate.
    Wax, chocolate, concrete are all substances which can be poured and have been used for sculptures…

    How you make a mold of an object depends largely on your object. You can find plenty of general instructions for mold making online.
    References :

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