Used to much decal softner

[Ian M]

A very good point Steve. One I sort of touched on.
Another good tip is keep an eye on the decal in the water. NEVER let them float off the backing. The Glue will also be gone. Wet them so the backing paper is wet then remove from the water. As soon as the decal loses its grip and can be slid on the paper, its ready. Apply and leave it. (a cotton bud or brush to nudge it around and remove excess water).
IF the decal has not dried down into the surface detail give it some softener. (You might want to consider diluting it with water if it works to harsh). Then LEAVE IT to dry and hopefully suck down into the detail.
Bubbles under a dried decal? Prick with a needle and give it a little softener and carefully press it down with a brush. Do not 'paint' the surface, gentle dabbing over the bubbles to remove air and introduce softener. Less is more! Just like super glue, adding more is not going to solve the problem, just make it worse. The less you can use the better. Put it on and leave it.

 

[stona]

Even after several days of drying it is still sticky.

It's always difficult to comment without seeing the 'damage', but that sounds like it may have been some reaction with the paints or varnishes. It is odd that everything has not dried after days.

I don't know what's in your MIG softener, but some quite 'hot' solvents can make DIY softeners. I've used everything from an acetone based nail polish remover to cellulose thinners (which probably contains acetone among other solvents). You've got to be VERY careful, you certainly don't splosh them on like commercial softeners*, but I've even had some success with Tamiya stickers, the ones that masquerade as decals. It goes without saying that such things can also affect paints and varnishes.

*Start with a barely moist cotton bud. Initially start with nothing much more than fumes, you can always add more and be more aggressive if nothing happens, but if you destroy the decal or your paintwork by being over eager there is no going back. If anyone fancies a go I strongly suggest a few trial runs on some old model or with a selection of spare decals before committing to your latest pride and joy. Some of the better decals, the ones with very thin carrier films, probably won't react well to such aggressive treatments!