Holiday Testing Of Coatings

Holiday continuity test on coatings.

Holiday testing of coatings. This covers the electrical test procedure that is adopted for checking whether there is 2. The holiday test is to be carried out for 100 of the wrapped and coated pipes using portable low amperage adjustable voltage and pulse type holiday detector employing an. Holiday test or a continuity test is one of the non destructive test method applied on protective coatings to detect unacceptable discontinuities such as pin.

Nace tm0384 holiday detection of internal tubular coatings of less than 330 μm 13 mils dry film thickness. Insufficient or excessive film thickness it is very difficult to detect holidays such as pinholes discontinuities and improper bonding of protective coatings as it can t be done during the inspection unless sophisticated equipment is used. The high voltage or porosity technique can be used to test coatings up to 25mm 1 thick and is ideal for inspecting pipelines and other protective coatings.

Holiday detection methods once full cure of the paint coating or lining has been established it can be tested for holidays. The first being the wet sponge method the second being the more widely used high voltage dc method. Coatings on concrete can also be tested using this method.

There are two main holiday detection methods. Running the holiday test because retained solvents in the coating can give false results. 4 2 electrical testing to determine the presence and number of discontinuities in a coating film is performed on a nonconductive coating applied to an electrically conductive surface.

Also measure the dry film thickness to make sure it is less than 500 microns 20 mils. Check with the coating man ufacturer about when a holiday test can be performed on a fresh coating. Discontinuity holiday testing of protective coatings a description is not available for this item.

If holiday detec tion is required for coatings thicker than 500 microns 20. The allowable number of discontinuities should be determined prior to conducting this test since the acceptable quantity of discontinuities will vary depending on coating film thickness design and service conditions. Holidays tests work on the concept of electrical conductivity.