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Re: [MW:12869] Paint drying for next coat.

By Materials & Welding


On Thu, Nov 3, 2011 at 1:02 AM, Vasantharao Pamula <vasantharao@yahoo.in> wrote:
Dear experts,

Can anybody give  me guidance to accept the paint for next coats.

I work as inspector, i need to clear the painted pipes (primed) for 2nd coat.

When i  go for inspection, contractor offered to me 1st coated  pipes ( Jotun paint  -Barrier  comp.A,   DFT required is 75Microns as per specification).

I observed a situation that contractor applied 1st coat, in few areas, patch-up work (repaint) has been done to get the required  75 microns.

When i touch the paint, it looks to me that paint has not  dried. contractor claims that paint is applied 6hrs back, per data sheet of that paint 3h is enough for repainting.

Now problem is contractor is asking me to clear the 1st coat for next coats ( Pipe undergo 4 coat paint system). I objected it as it looks  paint is not dried.

Queries

 1. Patch-up work is allowed on 1st coat?
 
Yes ....It can be patch worked on 1st coat ..but it should be in minor areas ....make sure before patch work All slag materials removal and surface should be free from sand particals etc....

2. What is the min. & max. paint thickness allowed (75 Microns is nominal).
 
Minimum 75 Allowed ..Maximum up to 120-150
 

3. What is the testing method to clear the paints  for next  coats.
There is few methods are using ..please check your client paint specifications ...which power tolong,blasting etc....
 
 
 
 
4. For Drying time, we should refer only  painters data sheet?
 
Yes ..it is Mandatory

5. When will be used tape bonding testing ( ASTM D 3359).
 
As per Project specification/Procedue/Standard
 
 


Thank you in advance

Rao.

08297552539











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Thanks  & Best Regards,

Suresh

Mobile No: 91-92 92 905 905

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