I've always used distilled water to place the decal. Even if it doesn't sit down just right I let it dry and then use the Micro Sol red multiple times until it conforms to the nooks and crannies. I think the microsol blue is meaningless. 

Hi Jon-A-Its

  Now you see what a lot of us have dealt with .I have found , depending on the paint used, that except for Testors , you need to use the decal set solution made by the paint mfgr . T.B.

Nearly finished, a quick coat of Humbrol Flat, (feel like the prodigal, returning to the Enamels family!)

Bits of 'fuzz' on the tanker body, which is from the a/b (dried flat varnish?) which brushes off easily.

Conclusions: The Humbrol Gloss & flat do spray well, & make the tramline edges of the Tamiya decals disappear, enough said.

But I wasn't happy with spraying the gloss onto the windscreens. Luckily this stripped off easily enough with IPA, H20 & a toothbrush, I will DIP them as recommended by Humbrol's Youtube Tutorials.

Well, there are stronger decal setting solutions like Soluset but I'm not sure they're better. In fact some of the stronger ones can melt decals...

What you've got now looks good. Though next time you might try washing the model off well and then spraying another coat of clear over them. Sometimes it will make the issues disappear. After all if you're going to sand them off in the end you don't have anything to lose there anyhow! 

Well after advice here & elsewhere, I wet-sanded the offending areas with MDC's 5 pack of sanding blocks and some fingernail sanding/buffing/finishing stick set from Primark (£1.00/$1.60 ish)





A quick coat of Humbrol Gloss later,

24 hours later USAF & hood number decals on with Humbrol DecalFix





& the residue, much less than the MicroSol/Set



Cleanup & final gloss tonight.

More Pics showing the thinner truck & decals on the tailgate, which were fine.

According to the instructions(!) on the bottle:

MicroSET (Blue Bottle) is brushed on to model where decal is to go.... etc & MicroSET (RED Bottle) is used to Soften Decal to conform to surfaces....

I used blue to position then red to set decals on 3 models. The Cartograf decals were a dream, as were the Tamiya decals on the Jimmy truck, but the Tamiya tanker decals were very thick, not helped by my cack-handedness.

Not mopping up promptly is the cause of the 'burn', so looking for recovery techniques

& is there a better setting solution?