Gloss paints

[blueeighties]

Good evening.

During the last 12 months, I have been using my airbrush more and more, and I am now at the stage where I am merrily weathering stock, and doing the odd full repaint here and there. (See my layout thread for pictures.)

I can now spray colours fairly consistently and get a decent coverage and finish, with the exception of 1 final hurdle. Gloss varnishes! Matt are fine, but I just don't seem to get on with gloss.

So I was wondering, is it a better idea to just spray the basic base colours of a project in gloss finish? Or are gloss finish paints just as tricky as the varnishes? I would hope they are just the same to use as matt paints, as it will save a bit of work, (no seperate gloss coat required).

 

Regards,

 

Lee.

[AngryMeerkat]

Getting something to gloss will always be more difficult than matt, that applies to any kind of paint or varnish. The reason is how the paint creates the 'gloss' look and how it must be applied to give the desired effect.

 

To create a gloss finish, the surface coat of paint (or varnish, but for ease we'll call everything paint) must be completely smooth, right down to nano level, as gloss is created by the even reflection of light in all directions. Any fine scratches, lumps, bumps, or orange peel will reduce the gloss as these imperfections create a directional reflection of light instead of an even reflection. Unfortunately due to the nature of gloss, the paint shows up all these little tiny problems tenfold compared to a matt finish.

 

The best way to get as close to a perfect gloss finish as possible is an art, and can take a LOT of practice to master. You want to apply the top coat of paint heavier than usual, as you want the paint to flow as it dries. This creates a beautiful smooth finish and the depth of paint helps mask the tiny imperfections that are inevitable (these happen in all scales, from models right up to aircraft and super yachts, which is what I normally paint). Now the problem - the balance between a beautiful heavy gloss coat and something that has more runs than a running track is a VERY VERY fine line. This is where practice and experience come into play, it's not something that can be taught.

 

Try getting some old plasticard and priming it. Then try glossing it by using a little heavier coat each time. You'll start with a rough finish, pass through an acceptable finish, hit the perfect finish, then end up with runs everywhere. Do this a few times, watching how the paint coat looks as its applied, and remembering how your airbrush was set up for each coat. After a short time you'll find that sweet spot, and become a glossing master. Beware - you WILL get cocky at this point and get runs! Don't worry, everyone does. Just stop, and remember the process of how you got that perfect coat, and you'll be back to perfect in no time.

 

Hope this helps

 

Mark

[blueeighties]

Thanks Mark, very useful advice.

Reading that, do you get a full deep gloss coverage from 1 coat? I keep getting the advice to build it up with lots of thinner coats, but surely if you need the gloss to dry each time before recoating, this process would take forever?

When I am spraying my usual matt finishes, I just wait until the 1st coat looks touch dry, (usually a couple of minutes), and then re coat, repeating until full colour density is achieved.

But with gloss its a mare, how do you know when its dry enough to recoat, if indeed you actually need further coats?

[AngryMeerkat]

You should never try to cover or gloss anything in one coat, it's a guaranteed way to get runs! Ideally you should aim for 3-4 coats ...

 

Thin 'gripper' coat - applied thin and light. This coat is the bridge between a substrate and the paint finish.

 

Cover coat - this coat is the 'density' coat and gives the paint its correct colour and depth. Can be 3+ coats if the paint is thin or is a (technical term escapes me, but basically the tints used to make the colour are relatively transparent) such as yellow/orange/red.

 

Finishing coat - this is the final coat, slightly heavier, and is the coat that gives the final finish. This coat is the most important on gloss as its this coat you want to flow nicely.

 

The above applies to paint and varnish/lacquer, primer is applied differently again. If you are using paint then varnish then you want to use the above to get the colour right, then let it dry. Apply the varnish the next day in most cases, as most modelling paints don't like the 'wet on wet' applications that can be used with other paints. Again the varnish should be applied as above, and a flash off time allowed between coats. There is no correct time for flashing of paints as it depends on temperature, humidity, type of paint, brand, carrier agent, and so on. As a rule of thumb I generally wait until I can see the paint starting to change, with model paints in a warm room that's usually about 5 mins.

 

If you're struggling with knowing when to re-coat gloss varnish then again an old piece of plasticard comes in handy. You should always do a very quick test spray on some scrap before pointing your airbrush at your pride and joy to ensure its spraying correctly - spray a piece of plasticard and if you're happy with the flow and spray pattern then immediately start painting your model. When you finish a coat, lightly touch a corner of your test spray and see if it is wet/tacky/dry. Wait until the test spray is tacky before applying the next coat, again spraying over the top of you're original test spray (more paint = more drying time) then apply second coat to model. Repeat this procedure until you are happy with the finish.

 

Mark