Black Clear Over Silver Paint

Black or Blue …WHY???

I have sometime get the questions about BL Silver Coat RT.

1 When I coated Topclear it becomes black
2 When I coated Topclear it becomes blue

In both it worked went through well up to Silver process. But it turns black or blue when on Topclear was on it. Today I will explain you that how to solve this problem and the mechanism.

It become Black

"I went through well all coating process with Silver. But I have a problem when I on the Topclear it turned dark…" I also had same situation many many time. There are several reasons why it happens.

Reason 1 : Too thin main silver film thickness
Reason 2 : it was not enough heat to dry

I described the mechanism of BL Silver Coat RT Please refer to picture below.

It is status after silver coated. Nanonized silver particles are arrayed uniformly. It will be reflected almost 100% of visible light.

The top clear reaches the surface of the primer layer which goes through the crevice between silver particles.
Black colour appears in topclear as you can see.

The reason of the above too thin silver layer it because black colour stand out visually. By the huge crevice between the silver particles then the black primer appeared. The other matter, it because is lack of drying. So silver colour wasn't enough to shine but the Topclear was coated in the early stages.

It becomes blue

It is only one reason it could be the solving this problem so refer to my explain…

Reason : Lack of drying at the each stage

The thinner and another components remain on the primer but if already coated the Topclear so both going to react then it will change to irregular silver particles array. If the overlap and arrayed disturbed by external factor so it will change to another that emphasis the reflect of the blue wavelength in the visible light. The blue will appear br emphasised to the human eyes.

Mechanism : Silver arrayed particles uniformly

Nanonized silver particles are arrayed uniformly. It will be reflected almost 100% of visible light

When Topclear is coated but if the lack of drying each stage on your work it will be the thinner and components both reacted to change an array irregularly state

The result is a silver array that is sensitive to light of the blue wavelength in visible light.

Countermeasures

Have you understood the reason why the silver surface turned black or blue after Topclear coated.

1 Thorough drying after the primer
Forced air dry: 80-120℃( by material) 30-60min is standard
Normal temperature: Leave 7days more ( around 25℃)

2 Perfect Silver coating
Since there are some tips for the silver coat the general countermeasures are described below. Please check the Silver coat original page for the detailed.

Spray gun set up
・Needle size : 0.8-1.3 mm
・Pattern : Full
・Discharge: 1-1/4 rotate back
・Air pressure: 0.2Mpa
・un distance: 15-20cm
Dilution ratio: Main Silver : Thinner=1:1.6
Main silver paint layer: 3-6 times
Forced air dry: 80-120℃/ around 20min
Normal temperature : Leave 7days more

The material can be withstand high heat, we recommend forced air drying at 120℃ at 20minutes.

Technique : BL Silver Coat RT

BL HY-COATER
PRESENCE Co., Ltd. / BADLAND
4-18-1 Minamikase Saiwaiku Kawasaki Kanagawa JAPAN
ZIP CODE : 212-0055
TEL +81-44-587-3139 / FAX +81-44-580-3431 / info@badland.net

Black Clear Over Silver Paint

Source: http://bl-hycoater.com/blog/it-will-turn-blackorblue-why

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