Hi guys! I have a trouble is my surface silicone not dry up. I was use: - NSP Clay (not sulfur) for sculpting - Smooth-on Rebound 25 for make a mold. - Smooth-on Ecoflex 30 for casting. Please help me! Thank you so much!!!
Last Edit: Aug 31, 2018 3:40:05 GMT -5 by khiettran
Post by ichyandscratchy on Aug 31, 2018 15:30:46 GMT -5
Your issue might be that you used Smooth-on products. After 20 years of working with rubber, I would not recommend using Smooth-on products. It looks like you are having issues with the rubber being sticky and not curing. The most likely cause of this is the release agent you used. Did you use a spray on release agent?
....I am not that familiar with Smooth-On products as I exclusively use Alumilite. What your attempting to cast is kind of a Gray area for me, I'm going to assume that the silicone rubber (Rebound 25) and resin (Ecoflex 30) are recommend for use with this type of project, a bust ......also I don't know if there are any special instructions that need to be fallowed from the manufacture....I can only give you advise on how I do things with Alumilite HS-2 or 3 RTV Silicone Rubber as you have explained that "The surface of silicone not dry up".....with that being said what your experiencing could/would be caused by the fallowing:
Catalyst not being shook/mixed enough ...as an example I shake the catalyst bottle that comes w/ Alumilite HS for 1 min. before use.
Being off on your mix ratio...again not that familiar with Smooth-On ( this would be akin to you going to a Microsoft/Windows forum trying to figure out what went wrong with your Mac/Apple) .....if there was not enough catalyst mixed in w/ the silicone this will significantly slow down the curing process or cause it to never fully cure. One thing that does help, as it has worked for me with this same issue, is to allow the silicone mold to be exposed to as much heat and humidity as possible by being placed outside....again your mileage may vary as I don't know the finer details about Smooth-On.
Not mixing the catalyst and silicone together long enough. I mix the catalyst and silicone together for NO LESS than 2 minutes...I use a stop watch to insure this.
I am truly impressed with anyone who can take a chunk of clay and make it into a work of art, or in this case a master to be cast.
Hi Brian & ichyandscratchy I followed the manufacturer's instructions, but I failed three times. I followed the A: B scale with an electronic scale. I stir before weighing and mixing A: B together. If you have a better plan than smooth-on let me know