PAINT DEFECTS B

PAINT DEFECTS - PART B

FISH EYES

·        It is look like a fish eye pictures that is some foreign material is entrapped into the paint coat and after painting the coat is pill off or blow out from the work surface.

·        It is caused due to applying of paint before proper cleaning of the work material and some foreign particles like dust, oil, grease etc. present on the work piece during painting.

·        Needs to proper cleaning or applying any surface cleaning method like sand blasting or shot blasting before painting.

·        It can be removed by using sander wheel or grit paper and after remove then apply the light coat on this surface.

                                   

BLUSHING

·        It is milky like surface finish looks after painting.

·        It is caused due to moisture content in the atmosphere during painting which accumulates on the surface of work piece. Paint is spread in zig zag lines having large space between two zig zag lines.

·        Remove by sander wheel and if the defect found in large area then apply blasting and paint coat.

                                       

UNEVEN PAINT FINISHING

·        It is the non-uniform paint layer on the work piece due to this somewhere having shiny look and somewhere is not.

·        It is caused due to moisture found in the wet film of paint coat during painting, uneven coat thickness due to using unskilled painter. Also occur if the temperature of work piece is changes during painting.

·        On those surfaces where paint coat is uneven, there is another coat should be apply on that surfaces of work piece after first coat is gets dry.

                                 

FADING

·        Fading is the defect of changing color shade where the irregularity or uneven surface found on the work piece.

·        It is caused due to moisture contain on the surface of the work piece and get entrapped after painting. The ultraviolet rays may be affect the paint shade.

·        If possible then sand the fading and repaint wherever need and avoid the moisture contain on the work piece. Check moisture % before painting in paint booth.

                                            

WRINKLES

·        It is the defect of paint when wrinkles that is rough paint surface found on paint coat.

·        It is occur when applying of second coat before curing of first paint coat. For higher wet film thickness it may occur and it is found when painting is done in higher temperature than atmospheric temperature.

                                      

BLISTERING

·        It is nothing but the broken and unbroken bubbles occurring on paint surface of work piece.

·        It is caused due to oil particle, grease particles, gas and dust entrapment into the paint coat. If the surface having salt contamination after blasting may occur this type of defect.

·        Need to match up those bubbles by using brushing before curing and using of sand after curing.

·        It should be prevent by proper cleaning of blast surface & salt contamination test on blast surface before painting to ensure the salt contain % on the surface.

                                      

PIN HOLES

·        It is deep holes found on the surface of paint which may throughout the paint coat up to work piece surface.

·        It is caused due to not doing proper atomization of paint spray.

·        Remove by using paint brush before curing and after curing needs to wipe out the holes by using sander and applying of new coat on that.