Silicone painting medium substitute for PSI-641?

I am going to be making some silicone puppets, and I watched the awesome tutorial about painting realistic flesh tones on silicone.  I have looked online for the PSI-641 caulking that is recommended in the tutorial, but all the companies I have contacted have told me that it is discontinued.  What other silicone can I use as a medium?  Can I just use a little bit of the same catalysed silicone that I am pouring up the mold with?



  • I spent two long days trying to get the mix on 100% silicone to make its way through an airbrush. It never carried the pigment well when it did go through and inevitably it would kick in suspension in the naptha and clog.

    Perhaps the thinning down instructions could be more specific and updated to usable materials.

    We did end up using the catalyzed silicone (Gel 10) in this case thinned and through the airbrush easily and it held the pigment beautifully. I'm not sure if it was the cab o sil, or the silicone (we skipped both) but  were able to to start immediately.
  • Hey there. I think Stan Winston's is going to make a tutorial from the Tim Gore Webinar he did. It would answer everything. I use GE 100% silicone from Home Depot and it works great. Thinned with Naptha. The cab o sil you should only really need at the end. I don't matte the base gel as I find it works way better to matte the final paint job.
  • Tim Gore uses GE Silicone II and oil paints.  I've used it and it really bites into the silicone.  Tim Gores Bloodline are awesome paints also. 
  • The GE silicone Tim Gore uses is good- widely available, too.  Make sure whatever you get is "clear".  GE also makes a high grade construction caulk called SCS 1200 that's more durable and UV resistant, but its harder to find and a little more $.  Shinetsu makes great caulking- I think its KT-45T -Burman's sells it.
  • I'm using RS Flowable Fluid 692-542 for both sealing and painting. I have heard Wacker Elastosil A07 was also quite good (especially if you are in a rush as it is a quick dry one).
    I used to work with Dow Corning 734 as well. I thinned all of them with D-limonene.
    Hope it helps :)
  • What's the difference between silicone 1 and 2?
  • RTV 1 silicones are single component silicones like acetoxy, alkoxy and oxime moisture cure silicone adhesives. RTV 2 silicones are two component like your platinum and tin cure silicones.
  • If you are talking about the difference between GE1 and GE2 silicones, it is the cure method. GE1 is an acetoxy cure and releases acetic acid as a cure byproduct. GE2 is a neutral cure and releases methanol and ammonia as a byproduct.

    The information above is partially correct but there are two types of RTV2 silicones. The two part silicones I mentioned above (which also includes a one part platinum silicone which cures with heat, used in dip molding) and also one part RTV2 silicones which are condensation cure silicones containing an organo-tin catalyst. Totally not confusing...

    Here is a link explaining it better than I can: RTV.htm

  • So the GE2 is the tin cure kind? So it will cure all the way through better than the GE1? I have been having a hard time with my caulking paints curing (was using some of the silicone adhesives and GE1) so this is good info to know.
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