Is it okay to wash decaled models with water?

[Trainman440]

Hi, I do apologize for the influx of painting questions, as this is my first time painting a brass engine and want to do it right.

So, I did the soapy water washing, I did the primer. I did the multiple thin coats of scalecoat ii paint, and I did the wait 24 hr between handling rule. 

Finally, Ive done the decaling with mircro set and micro sol. Onto the final step, which is clear coating and removing that gloss. 

Since Ive touched the model with my fingers during the decal process, should I be rewashing the loco with soap and water before clear coating? Would that ruin the decals since the glue they use is water based?

There are no visible finger marks, so the water washing would strictly be for paint adhesion not visual cleaning. 

Charles

[7j43k]

Microscale says, in their FAQ section, that it's OK to use some water to remove leftover decal glue on the model.  Soap/detergent was not mentioned.

Water, without detergent, will likely not remove any residue from your hand touches, as that will be more oil based.

All that said, I doubt there will be a bonding problem for your clear coat.  The important time for cleanliness is before the FIRST coat of paint.

I am, of course, presuming you weren't eating a sausage-burger while you were decaling.  Ideally, you washed your hands before starting decaling.

 

Ed

[SeeYou190]

Building on what Ed said.

You want to make sure that the binder that held the decal to the decal paper is all gone. This will show up as specks when the model is examined closely.

I use diluted dish detergent (Dawn, because we always have it on hand) mixed with distilled water. I use a very soft make-up brush, and rinse the model with distilled water.

Then I blow the model dry using compressed air at about 20 PSI. I do this at the paint booth, and then set the model on the turntable so it can be clear coated without touching it again.

OK, now that I said that. these are steps I only use on special models, like brass locomotives, where I want to do my best. I usually do not take these extra cleaning steps for workaday freight car models.

The stray finger-touch and left over decal binder residue is rarely visible beneath a clear coat.

-Kevin

[Overmod]

Part of the issue, I think, is associated with the vehicle in the 'clear coat'.  In the bad old days this would have involved some sort of organic solvent that would easily dissolve fingerprints and likely incorporate the oils seamlessly and at least relatively invisibly in the film.  A water-based product won't act on those fingerprints any more than Ed's no -detergent-containing flush would... and might not bond to the area under them either.

Probably the best approach when using a water-based coat over the decals is to observe strict discipline once the base gloss has been shot: wear clean gloves; don't scratch your forehead or nose etc. with the gloves on; work in a clean room without dust -- see Ed's precautions above.

I tend to be obsessive about rinsing after using even dilute detergent.  On the other hand, I suspect a water-base clear might require much less extensive or obsessive drying before the clear coat is shot...

[SeeYou190]

Overmod

Probably the best approach when using a water-based coat over the decals

What clear coats are water soluable that are commonly used?

The only examples I have used are Vallejo, and they give poor results compared to Testors.

-Kevin

[Overmod]

SeeYou190

What clear coats are water soluble that are commonly used?

There are a bunch coming into use in automotive and industrial applications, and as low-VOC craze spreads I expect to see more of them in hobby applications.

My naive appraisal of some of these is that exotic chemistry is used to get the 'water' solubility (for rinsing and disposal, I think, rather than ease of thinning or 'stretching') and some of them have potential danger with overspray or rebound inhalation, etc.  That might cut down on their marketing suitability for hobby sale!

In a way this is similar to the push for RoHS (resting on hands, snickering?) lead-free solder 'technology transfer' to hobby products.  More eork and probably more cost for even comparable results... but as with disappearing VOC materials, better keep up with how the Brave New Alternatives work...

[doctorwayne]

Trainman440

Finally, Ive done the decaling with mircro set and micro sol. Onto the final step, which is clear coating and removing that gloss.

Fully-set and dry decals shouldn't be affected by water, but plain water won't have much affect on fingerprints.  If there are visible fingerprints, a little dish detergent in water, on a clean cloth, and with a quick swipe, should take care of things without harming the decals.  Follow-up with a similar pass using water only.

I would suggest that if your decals were applied over a clear gloss coat, it would be beneficial to apply a second gloss coat over the entire area on which the decals were applied, as the gloss of the decals is seldom the same as the gloss on which they were applied. 
You can follow that application as soon as it's dry-to-the-touch, with your preferred clear finish, whether it's flat or semi-gloss. 

This extra step will make properly-trimmed decals look like painted-on lettering.

Wayne

[tankertoad135]

I wuzza gonna put in my 2 cents worth, but the gents have covered your question very well!!