I know this is an old post to reply to, I just couldn't help but spare a bit of information for everyone
Is there anything that i can use to make water slide decals adhere or be sealed better w/o top coating ?
Yes there is and you don't have to wait for good weather conditions for this since it doesn't involve any painting, yet.
Professional modelers use solvent based materials (Mr. Solvent), but if you really want the the effect and not the cost you can buy "solvent" the one used by manicurists. I tried my sisters' for kicks and it worked great.
Before jumping into applying solvent over waterslide decal be aware of the following:
Solvent is dangerous to your health and it is advisable to use this material in a properly ventilated room. And NEVER smell or inhale solvent.
- try a spare decal before using the rest, this will ensure that the decal can take the solvent without eating the design. Not all decals are created equal,
- if a decal is stubborn you may have to apply solvent after the first coat dries, some decals are created too thick because of the "top coat" during production,
- just like top coating removing it could ruin the area around it,
- it will eat the top coat where the design is "printed" on so you could be seeing only the design if you do it right,
- make sure the applied waterslide decal is pat dry with a paper towel because water will dilute the solvent,
- never use too much solvent over colored plastic because in due course it will react like cyanoacrylate or super glue to clear plastic.
- avoid the plastic at all cost specially if it reacts badly to the solvent,
- for a tiny decal a small brush (0 - 00) will do the trick,
- for a small decal a #1 brush would do,
- bigger decals can be either applied with spray (very risky) or large paint brush,
NOTE:
It would be wise to apply the decals over a single clear coat so you can redo the application with minimal work since the decal is not directly over the plastic.
Finish the job with another clear coat to even out the surface.
How does a properly applied solvent looks like?
- The design should look rough dry, all the "top coat" should be gone and it could not be removed even when rubbing.
What is the difference between top coating and solvent application?
- The topcoat will just apply a film of clear paint over the decal so you will notice the decals' surface coat and will only be evened out with more clear coats.
- Solvent will eat the decals' surface coat leaving the printed design over the plastic and will look like a dry transfer but harder to remove.
What is the advantage of using solvent on waterslide decals?
- Let's just say "you can apply decals where you've been having problem keeping them in place before".
What's the worse case scenario of a mistake?
- Since not all decals are created equal, you could see solvent eating the design as well. This happened to me before and the only solution is diluting the solvent or don't use solvent at all.
I hope this helps those who are still wondering how to apply a proper waterslide decal.
As mentioned, test the decals before applying this technique to the kit or you could be facing a disaster. I am not responsible for damaged kit because of you trying to speed things up.