Painting Defect 1

[Edy Achmad]

Hy there, i have a few question about painting defect,
now i run my shop for painting plastic material to supply metallizing process, but when we use basecoat material,most of them is not good, like there is bubble, or grain of sand, or even like a contamination.

if you have any clue of it, please give your opinion, thanks

 

[TugboatEng]

Have you contacted your paint supplier? If not, search "solvent popping" to give you some questions to ask your paint supplier.

 

[Edy Achmad]

solvent popping occur when curing temperature too fast isn't ? i thought, that is not my problems, cause before we place part to the oven, i can see the bubble at first.

sorry for the letter, English is not my first language.

Ramadhani

 

[MacGyverS2000]

Perhaps there is dust/detritus in the spray booth? I'd suggest oils on the part, but that typically results in an open pore rather than a bump. A picture would help us define what's actually there...

Dan - Owner

http://www.Hi-TecDesigns.com

 

[MintJulep]

Mold release still on the part.

 

[TugboatEng]

Mold release compounds usually causes "fish-eyes". Plastics are fairly permeable and perhaps could contain some contaminant that is rising to the surface during painting. Maybe run the part through the oven once prior to painting?

 

[Pud]

It could be the parts need drying prior to coating. Most plastics absorb moisture from the air. This is released when parts are heated.
What is the material you are coating?


Politicians like to panic, they need activity. It is their substitute for achievement.

 

[Compositepro]

Contamination sounds very plausible and you have obviously considered it. So what have you done about it? Use a microscope. There is nothing we can do to help you, given the information that you have provided.

 

[Edy Achmad]

1)Perhaps there is dust/detritus in the spray booth? I'd suggest oils on the part, but that typically results in an open pore rather than a bump. A picture would help us define what's actually there...
ans; soon i'll post the pict

2)-Mold release compounds usually causes "fish-eyes". Plastics are fairly permeable and perhaps could contain some contaminant that is rising to the surface during painting. Maybe run the part through the oven once prior to painting?
ans: so we need to oven the part before washing process ?

3)It could be the parts need drying prior to coating. Most plastics absorb moisture from the air. This is released when parts are heated. What is the material you are coating?
ans: most of our part use PP, and ABS.

4)Contamination sounds very plausible and you have obviously considered it. So what have you done about it? Use a microscope. There is nothing we can do to help you, given the information that you have provided.
ans: For the first time, i thought if contaminant is the main problems, but we have already change the cloth for washing part,and multiply time for maintenance paintbooth, but it still appear, so everybody on my place like thought that we can't handle about it, so we need to do something else.

Ramadhani

 

[TugboatEng]

Bake it after all of the washing and before the painting. Baking is a great way to drive off volatile compounds.

 

[dik]

Degrease it first, then bake?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Edy Achmad]

1) Bake it after all of the washing and before the painting. Baking is a great way to drive off volatile compounds.
ans: thanks for your advice, gonna try soon.

2) Degrease it first, then bake?
ans: we don't try that yet, cause the oldest way we know is de-grease first then spray with airgun, and after that we do the coating process. but, thanks for your advice, we'll try soon.

Ramadhani

 

[dik]

it was a WAG... trying to get rid of all possible sources of contamination.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Edy Achmad]

sorry for asking, what is WAG ?

Ramadhani

 

[dik]

Wild Assed Guess...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Edy Achmad]

that is the image of defect but after metalizing process


Ramadhani

 

[Jacob Henry]

Bake your material.