colouring silicone?

Hi, anyone know a good way of colouring about 40A hard silicone after hardening? is there any way of painting or lacquering it? the material will be stretched and bended, so do I have to add colour before hardening? in that case i might have a slight problem. any help appreciated!

I did endless research on this topic… found only one method. Which included using xylene and 220 grit sandpaper to rough up the surface- then clean with isopropyl alcohol, prime for paint… nothing happened. Basically, that method is claiming that underneath that silicone is a surface that you can paint on, when in reality, theres just more silicone.
As far as I know, silicone will repel basically any household or readily available chemical, adhesive, paint, etc.
If someone has an answer, I’d be very interested to know the process. This is a classic problem when ameteur painters use the wrong color silicone caulk to fill gaps in windows or trim, and then cannot paint over the caulking, giving a poor aesthetic - and no way around it.

Isn’t the 40A hardness essentially soft like a very flexible casting mold?

Visit your local industrial paint supplier. There are primers designed to be used on flexible surfaces. My limited experience was a few years ago so I don’t remember brand names. However, the shop I worked at used Dupont and PPG paints so the primer was compatible. We painted a few data cables for computer mice. The adhesion was better than stock primer but eventually wore and cracked. Still, if you’re going to stretch silicone drastically then I’m not familiar with anything that would work.;.

Is this a school project-short deadline low $$? These paints are mixed for spray guns. Is the silicone the simple household stuff or is it from a 2-part mix? If the latter I think you could dye it during mixing.

One of the best materials to adhere to silicone is… silicone. You might experiment with coloring the same silicone material and applying on top of your other silicone part. The stretching, hardness, and other crucial properties will be essentially identical. I don’t know how you would paint it without it running off, but if you can coat it with more silicone somehow, there might be a solution here somehow.

Have you tried roughing up the silicone with fine sandpaper and then dipping in in? I think I did this a long time ago. The ink is not interconnected so it should bend with no problem. Try it on a test piece first!

Sorry. Dip it in Ink.


Google the phrase “silicone pigment” and see what you get.

Here’s three …

have had alot of experience with this. the very best way to ‘paint’ silicone is to mix a small amount silicone base with the correct amount of catalyst, tint the silicone with an oil paint (the water in acrylic paint affects the chemical kick of the silicone) the colour you desire and cut the silicone with naptha, until it’s real nice and thin, and then proceed to airbrush (or HVLP spray) the coloured silicone onto your silicone piece. you may want to do some test runs to check what your new kick time is once you have cut with naptha before you go spraying it all over your piece. what you’re effectively doing is making your own paint with a silicone base. there are commercially available versions of this, but nothing is better than using the same silicone that you cast your piece with (unless you can find a silicone base paint meant specifically for your silicone). This method can sometimes take awhile to build a constant tone, but with patience, perfect paint jobs are within reach. hope this helps abit.
p.s. don’t forget to clean your airbrush out immediatly with clear naptha.

Thanks! That seems to be a good idea. This might even help making a smoother surface on the eventual bubbles and holes my original cast has. I hope it wont expand the volume a lot though, as the form needs to fit in a shell. I`ll experiment a little, thanks for great tips!