How to tell when FW resin is clean?

[Yodhrin]

I'm a bit stumped by my new Culln model; I followed exactly the same process I normally use to clean FW resin(almost-hot water with a 5:1 mix of dish soap and surface cleaner, plus a toothbrush scrub), but where before it's resulted in the model losing the shiny appearance that indicates excess mould release, this time it didn't. I've scrubbed it three time now, and it's still just as shiny as when I took it out the blister. At the same time, it doesn't feel oily.

Is there any way to tell definitively when you've properly cleaned it?

[Chewbacacabra]

A trick I use on FW models is to dull coat them prior to painting. It'll seal in any excess release and provide a nice painting surface.

[chromedog]

Sometimes shiny isn't a symptom of excessive mould release. Sometimes it's just where the mould was a very close contact with the resin and there was no release on that area.
Mould release isn't usually for preventing the resin sticking to the rubber, it's often used simply to minimise chemical interactions between the rubber and the resin (in a chemical erosion thing).

Try a drop of thin paint on it. If it beads and runs off, then it was mould release. If not, just shiny resin. Spray it with a primer (NOT GW spray paint) or a matt varnish like Dullcote, allow to dry then paint normally.

[TheBearminator]

A trick I use on FW models is to dull coat them prior to painting. It'll seal in any excess release and provide a nice painting surface.

I've had no problems with resin (even forgot to clean them sometimes) until I got started with my grenadier sergeant. He was ******* unpaintable, just as chromedog described it. The paint wouldn't stick! After some work with a toothbrush he was all right. :-)