[MW:3326] Re: Painting

Dear sardev,

                   I faced the same problem before with same coating system as i was working in Kuwait.  This problem is because of High Build Epoxy with the application problem of painter, not proper mixing of paint(Part A & B),   and in cold weather and if the relative WFTor DFT is high .

                  Mainly this problem is because of MIXING & application and not giving enough SWEETING TIME. Application of paint in high wind speed, paint noozle not at perfect angle of application as required, maintaining distace from  substrat to paint gun with proper nozzle tip.

 

after application of primer practically u will get the dft around 50 to 125 microns,

Intermediate coat of high build epoxy u will get the DFT including primer dft around 250-350 . this also makes a problem.... so try to control the dft between 200 to 250 as practical as possible for intermediate coat.

 

Regards,

Y.C.Shiva,

QA/QC Mechanical Engineer

Welding & Coating Certified,

Doha Qatar,

+974-6166465

 

 

On Sat, Sep 26, 2009 at 11:46 AM, Saravanan Mohan <sardev@gmail.com> wrote:

Dear Guys!!!!!!!

 

The project which I am involved following the paint systems as per client spec follows:-

 

Inorganic Zinc(75-100 micron) as a primer

High Build Epoxy(100-150 micron) as a Intermediate

High Solid Aliphatic Polyurethane(40-100 micron) as a finish

 

Total Dft between (215-350 micron)

 

After the complete curing of the finish coat visually I observed tiny pinholes like appearance or fish eye only inspector eye can find them.

 

Please give me the suggestion where the problem from? this appear in almost all the painted works which applied many different days, different paint batch followed by airlesspray method.

 

 

 

 

--
Yadav Shiva Chelliya,
Inspection Engineer,
Doha Qatar,
+974-6166465

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