How To/FAQ
How Does Temperature Effect Material?
Silicones
Cold temperatures do affect thecure of silicones, more with the platinum series since it cures quicker withheat and stops curing with freezing temperatures. Tin based silicones are notheat curable and will cure in cooler temperatures. The first hour of cure (Tinbased) will effect the final time the silicone cures. Very dry or low humiditywill also slow the curing process. Donot try to heat-cure the Tin based silicones. Adding more catalyst will cureTin based silicones and some Platinum based silicones quicker; although, thiswill affect the physical properties and the library shelf life. Platinumsilicones will cure faster with each degree of temperature over 90F (Notrecommended to cure by elevated temperatures unless pre-tested). Use MR-150parting agent when heating to help with the release process (Not recommended touse with temperatures over 150F). Heatsaturation for depth of rubber thickness needs to be factored in for final cureof silicone-- Add 1-hour for each 1” thickness.
UrethanePlastics and Urethane RTV’s
Urethane materials cure best whenthe temperature of the material is between 70F – 80F. As the material becomeswarmer it will react and cure quicker, and when it is cooler the cure processis slowed—if too cold, material may not cure. The temperature of the mold andmaster tool can also affect the cure process with similar results.
Epoxy
The best temperature for aconsistent cure is between 70F – 80F. If the epoxy material is quickly cured byusing heat, it can boil creating bubbles if you are not cautious. If the epoxydoes not cure properly you may see softening and/or dimensional distortionsduring heat exposure greater than 150F. Post cures at 125F – 140F are used to assure the completion of curebefore subjecting it to a higher temperature.
Polyester Resin
The temperature of the materialand mold will control cure of plastic with sticky surfaces or a finishedproduct with surface wrinkle marks. Clear resins are the most sensitive. Preheat molds to 100F. Use a lower percent of MEKP and heat to cure(100F – 125F).