Global Scale Modeller

Paul wrote: Tue Oct 24, 2017 8:55 am I’ve not watched wills video yet, but my last half dozen or so aircraft, including the 1/32 special hobby tempest we’re not glossed for decals or the enamel washes I used on them. Non of my car or bike bike are glossed before decals either and I have no issues at all with silvering. Matt paint can still be smooth

Paul wrote: Tue Oct 24, 2017 1:42 pm Im adding no extra effort, I'm just decaling like normal. I think its a case of try it for your self rather than speculating (thats aimed at everyone btw)

Stokesy44 wrote: Tue Oct 24, 2017 1:48 pm

Paul wrote: Tue Oct 24, 2017 1:42 pm Im adding no extra effort, I'm just decaling like normal. I think its a case of try it for your self rather than speculating (thats aimed at everyone btw)

Completely agree mate. I was simply asking if you had any pointers to avoid a rough finish. PSI, needle size, distance from the kit etc. I'm no luddite, but Lordy I need help sometimes.

Paul wrote: Tue Oct 24, 2017 2:18 pm I spray at about 20 psi, with a .35 needle spraying approx 4" from the model and nicely thinned with Ultimate thinner. I lightly mist the first coat on, continuing around th model till I've fully covered it, so very light thin coats. Hope that helps

Stokesy44 wrote: Tue Oct 24, 2017 2:26 pm

Paul wrote: Tue Oct 24, 2017 2:18 pm I spray at about 20 psi, with a .35 needle spraying approx 4" from the model and nicely thinned with Ultimate thinner. I lightly mist the first coat on, continuing around th model till I've fully covered it, so very light thin coats. Hope that helps

Thanks Paul, I'll certainly try that on my next kit. Much appreciated.

Kevthemodeller wrote: Tue Oct 24, 2017 4:32 pm Try looking at these mate:




This is how I use Ammo Mig paint and it works, not with standing the issues I've had with a few of them, the vast majority work very well. It shows the application of light coats.

Stokesy44 wrote: Tue Oct 24, 2017 4:44 pm Thanks Kev - I think I've spotted at least one thing where I am causing myself problems. I need to learn to cover the whole area being painted with a very light coat, dry it and start over. What I've been doing is filling in smaller areas too quickly, I do layer but I need to slow down, and apply the very thin layer across the whole area I am trying to paint.

bfrd wrote: Tue Oct 24, 2017 1:37 pm **Disclaimer** I didn't watch the video. I am thinking about this from a physical and theoretical standpoint only.

I guess I am a little confused by the physics of a smooth matte finish. If you were to look at the physical structure of a gloss coat under a microscope you would find a "mostly" flat surface. All light is reflected linearly and because the surface is flat the reflected light is very uniform. This is what allows us to see reflections in glossy surfaces.

Matte coats are rough by design. When light bounces off of the rough surface it goes in many different directions. Because the light is going in so many directions reflections are so diffuse they basically can't be seen.

It is physically impossible to have a completely smooth matte finish. If it were completely smooth it would be glossy.

Granted we are talking about microscopic differences, but physics are not subject to limitations in scale. If I am not mistaken silvering happens when the decal is not completely flat against the paint. This difference is angle causes light to be reflected differently. Obviously, this is much easier if the decal is placed on a flat surface such as gloss. However, with proper care (and chemicals) it is certainly possible to make them lie flat against a matte surface.

Imagine laying a piece of news paper over a book. It won't readily conform to the surface, but if you bend it you can get a fairly tight fit. Now imagine laying that piece of news paper over a layer of rocks. It will take much more work to bend the paper around all of the nooks and crannies. You will get wrinkles, because you cannot bend a flat object perfectly around a rough surface. If you use water to make the paper wet this becomes easier because the water softens the paper. You are more likely to tear the paper since it doesn't stretch very well. Decals would work in a similar fashion, though I suspect they do stretch at least a little easier. Chemical solvents also add much more control by softening the material and allowing it to conform to the surface. While we are very well aware of this happening at a macroscopic level (panel lines and such), it is also happening at a microscopic level.

I think my final point is that gloss coats should make decaling easier because the surface is more uniform. Decaling over matte surfaces is certainly possible, but cannot be done without more effort.

I am also not trying to start any kind of discord. I just have a background in chemistry and physics, and cannot understand the idea of a smooth matte finish.