The decals for the Corsair will not slide off the sheet. I keep them in warm water for a ridiculusly long time. The only way I can get the decals to slide is slip an Exacto blade under them to break them loose. This leads to a bunch of bad things, Thank God the decals after all the stuff needed to get them moving are fine. Is there something else Iican use rather than water to get then moving?
You can add just a couple of drops of liquid soap (like dish washing soap) to the water you soak the decals in. This also reduces air bubbles. i also spread some of this water on the surface of the model where the decal goes.
Maybe try using hotter water? I use a small Corningware bowl and generally nuke it for a couple of minutes, till the water feels hot, not just warm. And I’d leave the decal in the water till I can see it start to release.
While dishwashing liquid might help eliminate silvering by filling tiny pits in the surface below the decal film (which is what a gloss coat does, by the way), I’m not sure it’d help decals release from the backing paper. Unless the degreasers present in most dishwashing liquids might promote release?
Also, it may be that it’s a bad batch of decals. I’ve never had that problem with the decals in any of the Tamiya kits I’ve built. I have had decals in kits from other companies, like Wave, that were slow to release, but I found that starting with relatively hot water and letting them soak overcame that.
Hope that helps!
Best regards,
Brad