I'm having some difficulties with painting Platsil Gel 10, I was recommended as a cheap solution to buy regular oil colors mixed with silicone. To thin it out I used a small bottle of chemical clean heptane/gasoline. But I'm not satisfied with the look,the substance is to sticky (see the picture)
Any other ideas or ways to get a persistent paintjob done over platsil gel 10 silicone? would be greatly appreciated
after a lot of time a restart with my experiment with Platsil gel 10.
Anyone know witch is a right glue to paste the silicon on the plastic or fiberglass?
anyone tried it?
so the best way to paint by airbrush is Rs fluid silicone + silc pig?
I just re-read my post and realized it sounded like I'm saying I'd only pre-tint platinum silicone, but I think I lost my train of thought. :) I pre-tint all silicone casts. It's nearly impossible to paint over clear silicone, unless you are making a jellyfish or something similar.
I found a ton of misspellings in my post above, so please see my corrections in bold below:
Doug Henderson said:
A cheap trick to bond silicone to many different surfaces is to coat the surface that you want silicone to bond to with shellac. You can use most silicones as an adhesive as long as you are not trying to use a platinum silicone to glue a tin silicone. But you can go the other way.
For example: you can put tin silicone onto cured platinum silicone and you can put silicone caulk onto cured tin or platinum, but platinum won't cure against tin or caulk.
As far as painting, using brushes or airbrushes has more to do with the effect you are going for. Airbrushing leaves less chance for accidentky building up too much thickness.
I recommend pre-tinting your silicone with silicone pigments. In platinum silicone, proper silicone pigments are best, but I've sometimes used oil paints in small amounts. Dry pigments work well too in small amounts. Makeup powders tempera powder, flocking, lots of options. Tin silicones are even more forgiving. I mostly use the cheapest oil paints I can find.
I know there are a lot of other painting systems out there, but I just use GE Silicone 1 as my paint base. I thin that with either Naptha or d-limonene (preferred - expensive, but totally non toxic). Some use Coleman fuel or mineral spirits.
I color the silicone caulk with oil paints if I want a long working time, or acrylic if I want it to set up fast.
The standard mix ratio is 4 parts silicone to 1 part pigment, thinned with about 5 parts solvent. It can vary a lot from there, but I don't suggest much higher concentration of pigment. You can add tons of solvent to create washes and translucency.
As far as matting the silicone to eliminate shine, I've used powdered sugar for years. When the paint job is done, I spray a very dilute layer of clear silicone over the whole thing and then shake on a very heavy layer of powdered sugar. DONT TOUCH IT AFTER THAT! I let it cure overnight, then rinse off the sugar. This technique was taught to me many years ago by Tom McLaughlin and I stuck with it. Now I prefer to use cabosil mixed with clear GE silicone 1 and heavily thinned with solvent. I airbrush this on and it dries very quickly, leaving an almost dead-flat sheen. If it's too flat, I might lightly spray over that with plain GE silicone caulk thinned with solvent. Just to leave little droplets to bring back a tiny bit of shine.
Another cool trick that most people don't know is: you can make silicone molds with silicone caulk. And you can do solid or hollow (brush up) castings with it. I only suggest GE silicone I for this purpose. It does shrink a bit, so don't use it to make molds or castings that need to be super accurate, but it works really well. Right now I'm casting fish out of caulk for an upcoming film project and it works really beautifully.
The secret is to mix a small amount of acrylic paint into the caulk. This catalyzes it and makes it cure the whole way through. If you use a tiny bit of acrylic, you get a beautiful translucency and longer working time. More acrylic will make it set faster and makes it more opaque. I use clear acrylic medium if I want the silicone to stay clear.
Hope these tips are helpful!
Hi Doug. Thanks for sharing all your tips. I too have found icing sugar to be really effective. Will look up d-limonene, which I haven't come across. I tend to think we're not using naptha in large quantities so I don't wear a mask. But anything that is less toxic has to be good.
Doug, can I ask a question about the GE silicone caulk you use?
Is it an acetoxy silicone? Presumably it does not contain fungicides, as it advertises itself as 100% silicone.
I am just wondering about the other silicones available, and whether they are also suitable. I have used glazing (non-acetoxy) silicone for attaching hair to Platsil, but never tried using it for painting. My hunch is that it would be fine for that too. So just wondering what the differences might be.
Hi Doug. Thanks for the info.
Glazing silicone is not acetoxy, that's the difference, so it may work differently, although it seemed fine for the hair patches.
I got some d-limonen today, so will give it a go too. Thanks for all the tips!
I forgot to report that silicone colored with acrylic doesn't stick well to the shellac and is probably the cause of most issues I've had randomly in the past. it is fine with a little oil paint, but works best with just untinted silicone caulk first.
Happy New Year everybody!