Timing of DFT inspection and Water spray test for Thermal Spray Aluminum
Timing of DFT inspection and Water spray test for Thermal Spray Aluminum
(OP)
Dear respected TSA expert,
Im new to TSA and have been reading several specifications.
However, i can not see any specification specifying the timing of inspections for TSA DFT measurement and water spray test.
My undestanding of inspection sequence is as follows:
TSA Coating -> DFT check (specification does not specify when - 1 day after TSA application?) -> water spray test.
Your inputs will be highly appreciated.
Thanks,
Im new to TSA and have been reading several specifications.
However, i can not see any specification specifying the timing of inspections for TSA DFT measurement and water spray test.
My undestanding of inspection sequence is as follows:
TSA Coating -> DFT check (specification does not specify when - 1 day after TSA application?) -> water spray test.
Your inputs will be highly appreciated.
Thanks,
Talk To Other Members
RE: Timing of DFT inspection and Water spray test for Thermal Spray Aluminum
One of the great qualities of TSA, is instantaneous cure. As long is the surface is not so hot as to damage your gauges or cause any safety concerns, you can check DFTs as soon as you'd like. Typically we wait 15-20 minutes with temps of 70-80F.
Once DFTs have been found in compliance, the water spray test can be followed immediately afterwards. There are two notes I will make in regards to water testing.
1) If possible, it is always better to use rain water, rather than tap water. I have personally witnessed water testing for 2-3 days, and no rust bloom occured. The material was picked up and delivered to Exxon, where it sat on the ground for roughly 1-2 weeks. During the end of this time period, we saw the first thunderstorm in roughly a month. We received a phone call the next day, requesting a site visit. Upon inspection, roughly 10-20% of the total surface area had rust bloom present.
2) Some companies have different definitions of a "water spray test". Shell, for example, requires that you continuously water the TSA for 24 hours(via sprinkler or similar method). Other companies/specifications do not list this requirement.
Hope I could be of help.