Thinning oils without damaging acrylics

[Evil Eye]

Having recently dived into the use of oil paints for weathering and shading and the like, I've found myself quite in love with them. You only need a tiny amount of paint to get a lot of coverage and the blending properties are just wonderful. Unfortunately I have hit a bit of an issue- whilst it does work, I've discovered that the enamel thinner I was using to thin them with can strip off acrylics if you aren't careful.

 

This makes perfect sense as enamel thinner is quite fearsome (though I will say it works very nicely for thinning oils) but is nonetheless frustrating. I have since purchased some oil-specific odourless thinner, but have yet to try it out. Will this still risk damaging acrylic paints? Should I use white spirit instead? I've also heard mixed things regarding whether you need to varnish before applying oils, some say it's a necessity whilst others say there's no need, so any advice on that would be appreciated.

[Firedrake Cordova]

Marco Frissoni on YouTube uses oils over acrylic for a Blanchisu style a lot.  He's got a primer video, but a gentle stroll through some of his others might be a good idea.

 

"Beginner's" video: https://www.youtube.com/watch?v=x_pxojd7kp8

 

TL;DW: he uses white spirit

Edited August 10, 2020 by Firedrake Cordova

[Lovecraft0110]

Hi Evil Eye,

 

You need to varnish first, and odorless thinner is gentler than white spirits. I have several videos on this. This one, for example, could be useful:

 

 

If you have any other questions, you can join my YT Channel's Discord.

[Arkhanist]

I use pebeo odourless mineral spirit for thinning my oil weathering washes as it what my local art shop had - it's less harsh than enamel thinner, which is overkill for diluting oil washes. Other odourless white/mineral spirits equivalents are available, and are all fairly similar, and less harsh than enamel thinner. Rule of thumb though, before doing oil weathering, do a quick varnish coat first to protect the acrylic layers - not least as you usually mechanically remove excess oils with say a cotton bud. It's not 100% necessary, but it depends upon how robust your acrylics are - inks and Contrast are more fragile than GW layer paint, for example. It also means you can remove almost all the oil wash with fresh spirits if you accidentally overdo it. It's trivial with an airbrush, so I always do a varnish coat pre-oils.

 

I use gloss PU varnish over the acrylics as a) that makes the oil washes flow better and more controllable with a gloss surface, and b) the oils tend to dry quite shiny so need a matt varnish finish coat anyway, before final weathering pigments (I use dedicated pigment fixer for those)

[Spacecow]

I use liquitex Matt varnish ( but any varnish will do) and abteilung thinners. They have odourless ones and also faster drying ones.

I also have some Windsor and Newton oils that are water based that work really well so I can avoid having to use white spirit :)