Skip to main content

Re: [MW:15410] Tollerence for Painting DFT

Dear,

Standard: SSPC PA 2

5.2.1 Minimum Thickness: The average of the spot measurements for each 10 m2 (100 ft2) area shall not be less
than the specified minimum thickness. No single spot measurement in any 10 m2 (100 ft2) area shall be less than 80% of the
specified minimum thickness. Any gage reading may under-run by a greater amount. If the average of the spot measurements
for a given 10 m2 (100 ft2) area meets or exceeds the specified minimum thickness, but one or more spot measurements is less
than 80% of the specified minimum thickness, additional measurements may be made to define the non-conforming area.

5.2.2 Maximum Thickness: The average of the spot measurements for each 10 m2 (100 ft2) area shall not be more
than the specified maximum thickness. No single spot measurement in any 10 m2 (100 ft2) area shall be more than 120% of the
specified maximum thickness. Any gage reading may over-run by a greater amount. If the average of the spot measurements
for a given 10 m2 (100 ft2) area meets or falls below the specified maximum thickness , but one or more spot measurements is
more than 120% of the specified maximum thickness, additional measurements may be made to define the non-conforming
area. Manufacturers’ literature may be consulted to determine if higher maximum thickness readings are allowable under
specific circumstances.

Also you can see ASTM D 1186

There may be no. of reasons for failure in test.

What was required DFT ?

What was the max DFT observed ?

What is the average DFT observed ?

For Proper Pull Off test refer ASTM D3359

Test Method A—An X-cut is made in the film to the substrate, pressure-sensitive tape is applied over the cut and
then removed, and adhesion is assessed qualitatively on the 0 to 5 scale.

Test Method B—A lattice pattern with either six or eleven cuts in each direction is made in the film to the
substrate, pressure-sensitive tape is applied over the lattice and then removed, and adhesion is evaluated by comparison with descriptions and illustrations.


Test Method A is primarily intended for use at job sites while Test Method B is more suitable for use in the laboratory.
Also, Test Method B is not considered suitable for films thicker than 5 mils (125μm).



On Wed, Sep 26, 2012 at 12:47 PM, Ramchandra vichare <vicharerke@indiatimes.com> wrote:
Dear Experts;

with reference to the subject referred above please let me advise with documentary evidence about tolerances for  Painted items when DFT is specified. Why paining fail in cross cut/peel-off test(Pl. ref photograph attached)? How to control the same?

Requested to advise

Regards
RK Vichare

--
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
http://www.linkedin.com/groups/MaterialsWelding-122787?home=&gid=122787&trk=anet_ug_hm

The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.



--
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
http://www.linkedin.com/groups/MaterialsWelding-122787?home=&gid=122787&trk=anet_ug_hm
 
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
 
 

Comments

Popular posts from this blog

Re: [MW:34105] SA266 GR4N 4 Cycle SPWHT

Hi,  You are correct, Minimum refers to the one cycle for which this part will expose until final work shop PWHT. hence mill test certificate shall include this.  Max. SPWHT, refers to additional cycles of heat treatment that are reserved for future repairs during equipment lifetime.  Again, these simulated no. Of cycles shall be specified in MTC.  The idea is we need to make sure that steel mechanical properties are not compromised upon exposure to multiple repairs (i e 4 cycles in your case).  One could say, if steel is subjected to 4 cycles and is ok, then it should by defacto be good for one cycle, yet, this is wrong assumption cause mechanical problems and microstructure of materials varies accordingly based on no. Of cycles for which material will expose. This is apparent in alloy steel and especially for impact test values as an example.  In your case, this forged CS with properties before PWHT can be understood to be " as forged" condition (i.e. Wit...

Heat tint (temper) colours on stainless steel surfaces heated in air // Heat tint

Introduction The colour formed when stainless steel is heated, either in a furnace application or in the heat affected zone of welds, is dependent on several factors that are related to the oxidation resistance of the steel. The heat tint or temper colour formed is caused by the progressive thickening of the surface oxide layer and so, as temperature is increased, the colours change.   Oxidation resistance of stainless steels However, there are several factors that affect the degree of colour change and so there is no a single table of colour and temperature that represents all cases. The colours formed can only be used as an indication of the temperature to which the steel has been heated. Factors affecting the heat tint colours formed Steel composition The chromium content is the most important single factor affecting oxidation resistance. The higher the chromium, the more heat resistant the steel and so the development of the heat tint colou...

Materails FAQs

Q: What are equivalents for standard Q 235 B (and Q 235 A) for U-channels? (asked by: boris.vielhaber@vait.com) A: DIN Nr. = 2393 T.2, 2394 T.2, EN 10025 W. Nr. DIN 17007 = 1.0038 Design DIN 17006 = RSt 37-2, S235JRG2 (Fe 360 B) Q: What is St DIN 2391 BK material? (asked by: dmcandrews@automaticstamp.com) A: Precision steel tubes, cold-finished/hard. Q: What is C.D.W. Boiler Tube? (asked by: montydude123@yahoo.com) A: Cold Drawn Welded Boiler Tube. Q: WHAT IS W.Nr. 1.4301? PLS TELL US IN EASY LANGUAGUE (asked...