vessels internal coating checks

[gsnmech]

I have a few vessels with bad coating in sea water systems like not uniform thickness, sand on the coating, improper cleaning before coating at some locations. What check can be done on the internal of vessel to check the coating quality after a repair job or when ever i received a vessel after a coating.

 

[SnTMan]

gsnmech, the first is visual, if it looks like a crappy job as you describe, don't accept it.

Second, is a test for the integrity of the coating via a test for "holidays", which I beleive is a spark test. I don't know the details and disremenber which ASTM standard covers it, but you should be able to google it up.

Third is applied coating thickness, again I don't know the details but these are all routinely done.

Unfortunately, proper surface prep is going to be hard to check after the fact. Maybe make it a hold point.

Regards,

Mike

 

[metengr]

What check can be done on the internal of vessel to check the coating quality after a repair job or when ever i received a vessel after a coating.

First off, do you even have a specification for coating performed by a contractor? What is the type of coating yo need for the service application, required thickness, etc??????

If you do not have a coating specification for these vessels, you have nothing. This is more than just checking coating quality, you should have a detailed specification.

 

[vesselfab]

And an inspector to check and accept it at the coaters.

 

[micalbrch]

I think ASTM D429 (Standard Test Methods for Rubber Property -Adhesion to Rigid Substrates) is one of the standards you need.

 

[gsnmech]

we have coat thickness to be achived in each coat and the number of coats and the coat material is also specfied. We have done thickness test and found the coat to be not evenly coated and at some palces the caoting thicness was below the required level.

The holiday test will be good test and i was looking for some test quality of the surface preparation.

any way thank u for the replies.

 

[eyec]

check SSPC specifications for surface prep requirements