Decal Solution Residue

[Dougboy]

Not sure if this has been brought up before:

When applying thick decals over compound curves, the combination of decal solution, heat from a hairdryer and plenty of patience will usually give me a decent result. Problem is.... the heat from the hairdryer seems to dry up the decal solution pretty quickly and what's left is a sort of white residue. It's almost like watermarks that don't come off. I've tried gently rubbing it with a cotton swab soaked in water and the decal solution itself and it doesnt seem to go away completely. 

My next course of action will likely be a very light sanding or polishing to rub off the watermarks but that seem abrasive and might risk damaging the decals that took so much effort to lay on in the first place. 

 

Any tips and pointers would be much appreciated. I use Mr. Mark Softer if that matters. Do "weaker" stuff like microsol not have this issue? 

 

[peteski]

What brand/type of paint are you using?

Decal set/sol solutions can affect the paint, and they can also leave some residue, but that is usually easily removed with water.  The weaker formulas (the ones which smell like vinegar) should not leave much residue (but might not do good enough job getting the decal to settle down).   Have you tried removing the residue by gently rubbing it with a cotton swab dipped in the setting solution itself?  If you do this quickly, it should not affect the decal.

[Brutalform]

I’ve always used the Microscale set/sol, but decided to try that new Tamiya Mark Fit decal solution, in the yellow labeled bottle. Had the problem you described. I went back to the Microscale. 

Edited May 16, 2019 by Brutalform

[Slimguy]

I had the same problem with the Tamiya Mark Fit.  On dark decals it left what appears to be water spots on the decal.  Might have to switch to Microscale.

[Dougboy]

So I guess the issue stems from the stronger solutions from Japanese manufacturers. I love how this "stronger" stuff could make any decal conform , especially when working with CF.   I've not used microsol before and I'm afraid it wont be quite as effective, especially with thicker decals from Japanese kit makers like Tamiya....or would require extra application and patience. 

[Jim N]

Have you tried the decal setting solution without the heat?  I have been using Micro Sol and Micro Set on Tamiya kits for years and the decals conform to the model fine.  For what it's worth, here are a few examples.

[Jantrix]

5 minutes ago, Jim N said:

Have you tried the decal setting solution without the heat? 

What he said. the heat is your trouble I think.

[Brutalform]

I should have never strayed from Micro Scale, knowing how well it works. I bought the Tamiya solution at my LHS, to give it a try. After three uses, I was doing more work trying to get the residue off, and putting the decals at risk of being ruined. Actually, now I wonder why I even wasted my money. I normally don’t stray away from things that are known to work well. 

[gijoe]

My favorite is solvaset.  It's stronger than microsol, so you need to be careful, but with the right technique it produces the best results I've seen. I've never had issues with residue using this stuff.  Since it is so strong, I paint on a layer, then immediately brush over it with either a q-tip, or paint brush wet with plain water, then I turn on the hair drier and gently conform the decal to it's final shape.  Don't ever leave undiluted solvaset on for very long, it's too strong and will dissolve the decal.  

 

I will say though, that each individual's technique will play a roll in what setting solution works best.  My technique involves 0 wait time, I lay down the decal, get it as close to the final position as possible, paint with solvaset, followup with a wet brush, and heat, snug the decal down with the heat on, wipe the surface clean with another wet q-tip, then leave to dry.  

Edited May 16, 2019 by gijoe

[peteski]

One possible solution to your stains is a clear coat.  Usually applying clear over the descaled paint surface (which I always do) makes stains and clear decal film disappear.

[martinfan5]

9 hours ago, Jantrix said:

What he said. the heat is your trouble I think.

I can confirm that the heat is not the problem, I use both Tamiya Mark Fit and Mark Fit Strong and Mr Hobby and I have the same issues and I NEVER use heat.

One thing to try is wipe the standing solution away,  cover the decal, let it sit for a minutes, and then carefully wipe away, don't leave any standing solution to dry .

Edited May 17, 2019 by martinfan5

[gijoe]

11 hours ago, martinfan5 said:

I can confirm that the heat is not the problem, I use both Tamiya Mark Fit and Mark Fit Strong and Mr Hobby and I have the same issues and I NEVER use heat.

One thing to try is wipe the standing solution away,  cover the decal, let it sit for a minutes, and then carefully wipe away, don't leave any standing solution to dry .

I agree that it's probably standing solution causing the staining with that particular setting solution.  I always use heat.  The only time I have gotten stains and residue is when I've left the solution on to dry naturally, it beads up, and leaves behind stains.  Dougboy, consider giving my technique a try, a strong solution will have enough time to soften the decal while you wet a brush and start to dilute the solution on the surface of the decal.  I really only leave full strength solvaset on for a few seconds before I go over it with a wet q-tip, that's all it takes.  With care, and soft q-tips, I think you'll be able to get the decals nice and snug without leaving behind any unwanted residue.  

[Jim N]

Why do you guys use heat and what does it accomplish?  I hope this does not come across as being snarky.  I have never heard of this technique and am curious.

[gijoe]

26 minutes ago, Jim N said:

Why do you guys use heat and what does it accomplish?  I hope this does not come across as being snarky.  I have never heard of this technique and am curious.

For complex curves, heat will soften the decal and allow it to stretch better.  When doing custom carbon fiber around curves and small details, setting solution and heat are by far the best way to snug the decal down.  It probably isn't at all necessary over a flat, or gently curved surface, but it makes all the difference when it comes to the tricky bits.  

I can get some pictures later showing just how perfect you can get decals to conform without hiding details.  

[Jim N]

Thanks Joe.  I would appreciate seeing the pictures when you have some time.

[gijoe]

No problem, Jim.  I'll plan on getting some together later tonight, or tomorrow. 

I'm by no means saying that my technique is the only technique people should use, but I've found this technique to work the best for me.  I've become very comfortable with doing it that way, and the results have been very consistent across several different brands of decals.  

[Dougboy]

Thanks gijoe, your suggestion of dispersing the liquid with a Q-tip before it has a chance to fully dry does help. I guess the key is really just to be more patient, doing few more dab/soak of the decal solution and doing more low low heat passes with the hairdryer. The clear coat after should take care of the rest in hiding the watermarks. 

 

As for heating up the decal as it dries, its not really necessary for cars, especially older model vehicles with flatter panels. But its absolutely necessary for Formula 1 bodies and more so when CF decals are used around complex aero bits.