Decal gloss coat question

[cct70]

I'm building a few Western Pacific cabooses in HO and am *almost* to the decal stage on one of them (one of them is stalled until I get some more white paint and the other hasn't been started yet). Question I have is regarding gloss coat prior to decal installation. I have heard numerous times that the recommeded practice is to apply decals to a glossy surface, but never could understand why? I prefer to shoot flat paints rather than gloss as the finish comes out much better, and seal with dullcoat if I want a flat finish over the decals and gloss coat or a mix of flat and gloss for newer equipment. Spraying a coat of gloss, then decal install and then another coat of gloss just seems like too many layers to me, especially if I want a flat finish ultimately anyway. What is the advantage of gloss substrate for the decals? does the gloss paint give better decal adhesion? Or does it *really* matter if I go with gloss or flat surface first?

 

[ICG/SOU]

does the gloss paint give better decal adhesion?

Yes. With flat or uneven surface, it's a risk for poor adhesion.

 

[CP9302]

Decals will adhere to a glossy surface better and the clear film around the decal will be hidden better on a glossy surface.

You only 'need' the gloss coat before the decals, not after. You can seal the decals/model with a flat or satin finish. As long as you keep the layers of clear coat thin, you won't notice them.

 

[fast_ian]

Decals will adhere to a glossy surface better and the clear film around the decal will be hidden better on a glossy surface.

+1

.... As long as you keep the layers of clear coat thin, you won't notice them.

+1

I have a passenger car on which I practice clear coat application - I find it harder than color for obvious reasons.......

Cheers,
Ian

 

[Dortoh1]

The decal will adhere better, but also the clear edge of the decal will be less visible. Some times on a flat/dull surface the clear part of the decal can look hazy. That is why I like to use Scalecoat II paints, they are very glossy to begin with, so no clearcoat before decaling is needed. Then when I'm done decaling I can either apply dullcoat, or gloss, or a combination of the two, depending on how I want to weather, to seal and protect the decals.
I've attached a picture of some F3's I'm building that are painted with Scalecoat II. They are in the middle of decaling in the photo (all of the yellow stripes are decals) so they have not been clearcoated yet. I find that the decals go on much better on a glossy surface.

 

[tomstockton]

Gloss vs. flat surface, as it was once explained to me...

The particles in flat paint are very uneven in shape -- as the solvent evaporates, the surface will resemble a field of boulders. As light reflects off of this surface, there is a little bit of scattering, which gives the surface its flat look.

On the other hand, the particles in gloss paint are much more uniform in shape -- as the solvent evaporates, the particles nestle in with each other much more evenly, more like a brick wall. This generally eliminates much of the spaces between the particles, and gives the finish its shiny, glossy look.

The "silvering" occurs when the decal is applied over a flat (matte, not glossy) surface. The irregular shapes between the particles of paint form air pockets. As the light is reflected off of these air pockets, you get that "silvering". However, with a gloss finish there are very few (if any) air pockets, so there is little (if any) silvering. A side benefit of the gloss finish is a much more level surface the decal is adhering to, so the decal has a better "grip". But with a flat surface, there are all of those air pockets, which means the decal is only adhering to the "high points" instead of the entire surface. Decal setting solutions will help some, but usually not enough to offset the uneven surface of a flat finish.

So (as I understand it), you should apply decals to a glossy surface; then after the decals are thoroughly dry, you then apply a clear flat finish over the entire model.

Hope this helps!

Regards,
Tom Stockton

 

[cct70]

Thanks guys! I have finished one car now and working on decals for the 2nd, and you're right, the decals are adhering much better to the glossy surface. I then dullcoated the finished car and got the look I want.

Those Red F's look killer. Anymore shots of those or similar engines?

 

[diburning]

Here's a tip. Krylon Crystal Clear comes in a larger can, is only about 4 bucks, and come in gloss, satin, and flat finish varieties. They're acrylic so they don't react with certain paints that dullcote (which is a lacquer) or other types such as solvent based clear coats could do. (I've had dullcote react with and separate an acrylic based paint)

Works just like glosscote and dullcote.

 

[RexHea]

Eric: I also have started using Krylon Crystal Clear: both gloss and flat. The results were excellent and darn sure Cheaper!

 

[Dortoh1]

Tom, here are a couple new pics of the F's, cell phone quality but it's all I have of them right now. The railroad is my own Roanoke & Western. The decals were made by a friend with an Alps printer.
Doug

 

[cct70]

I REALLY like that scheme.

 

[IowaFarmBoy]

Here's a tip. Krylon Crystal Clear comes in a larger can, is only about 4 bucks, and come in gloss, satin, and flat finish varieties. They're acrylic so they don't react with certain paints that dullcote (which is a lacquer) or other types such as solvent based clear coats could do. (I've had dullcote react with and separate an acrylic based paint)

Works just like glosscote and dullcote.

Be warned that for me applying Rustoleum Painter's Touch Clear over acrylics had a much different effect. Strip and re-paint time after that. Krylon Crystal Clear has never done that for me. I use all 3 finishes and seal the homemade decals I print with Crystal Clear to keep the ink from running.

 

[Outback]

Here's a tip. Krylon Crystal Clear comes in a larger can, is only about 4 bucks, and come in gloss, satin, and flat finish varieties. They're acrylic so they don't react with certain paints that dullcote (which is a lacquer) or other types such as solvent based clear coats could do. (I've had dullcote react with and separate an acrylic based paint)

Works just like glosscote and dullcote.

So then, could you not just apply a dull finish clear coat - which in essence should be a smoother surface than a flat paint - and then the decals? Or does it work in the same manner as flat paint particles?

 

[diburning]

So then, could you not just apply a dull finish clear coat - which in essence should be a smoother surface than a flat paint - and then the decals? Or does it work in the same manner as flat paint particles?

Decals need a flat surface to adhere properly. Glosscote has more even particles while Dullcote has rougher particles. The Crystal Clear is the same. The Crystal Clear is acrylic based so that it will work on acrylic paints such as Polly Scale as well as solvent paints such as Floquil. Crystal Clear comes in Flat, Gloss, and Satin.

I've found that Testors Dullcote reacts with some acrylics even while dry, causing the paint to separate and bleed into the dullcote.

The Crystal Clear is fine enough so that it's a perfect alternative for Dullcote and Glosscote. They're also less expensive (about 3 bucks at Walmart for a can twice the size of the Testors version) Crystal Clear is available at WalMart, Ace Hardware, Home Depot, and Sherwin Williams (who owns the brand)

 

[Outback]

OK thanks. It just seems weird to me to paint a gloss coat only to then dull it all after decalling. I never was very tech savvy with my painting proceedures lol.