There's two types:
- decal setting solution
- decal solvent
Generally they are available in the 'Micro' range of products, but I've seen them in other jars too (I think one was PollyS). The idea is that you put some of this on the surface of the model first, then lay the decal on top, then coat with more of the solution. You do this all with the products 'wet' and basically they cause the decal to 'soften' and snug down into the little details and crevices of the model. It will also allow the decal to conform to curved surfaces better.
Some things I'm still learning:
- I *think* the 'solvent' is just a stronger form of the 'setting' solution. It really makes things soft and chances are that if you touched the decal it might rip or fall apart very easily. The idea is to put the solvent on and then just LEAVE IT ALONE until it dries. It might cause the decal to crinkle up a bit, but JUST LEAVE IT ALONE and it will level back out and conform to the surface.
- either one of these will soften the decal quite a bit. So, make sure the decal is in place and don't be moving it around a bunch once you've got the solution on it. Chances are that the decal will tear.
- I've heard that you can use household vinegar and that it will give you the same results. I tried it once and it seemed to work OK.
About your bike:
I don't suppose you're putting the decal on a surface that was painted with a flat/mat paint? If so, that's probably your problem because decals don't sit on flat paints very well. Judging from your prior posts and the type of model (there's not a whole lot of flat paints on a racing bike...), I doubt that this is the issue, but I thought I'd ask anyways.
Hope that helps... If not, keep asking and perhaps someone else here will have the correct answers...
M.