Marine Wiki Forum

Recently we came across an interesting problem in our project. The paint makers (CMP) and IPK) in connivance with the shipyard (HHI) came out with a research piece with the title, "The effect of welding fume for coating performance".

Before I go in to the debate, let me get the facts straight. We all know that the welding or cutting on a steel plate can cause what is known as fume on the opposite side or on areas beyond the weld zone. It is also well known that these are alkaline in nature and that painting should be done on neutral surface. Given these facts, it is only obvious that painting on such surface will not give a long lasting coating. Only a proper surface preparation (blasting or power tooling) can ensure a proper coating.

In a shipyard, during construction of the ship, there are various areas on the steel plates that are subjected to such damages. It is expected that yard, ensures that such damages are rectified before painting. Now this means that lot of manhours as well as delays are caused in such repair. Hence the shipyard and the paint makers came out with a brilliant (allegedly fabricated) research report. Let me walk you through the conclusions:

1) The higher the fumes (read damages) on the plate surface, the higher is the creep resistance!
2) Cutting fume do not seem to have any effect on the adhesion of the paint
3) Cutting fume increases the life of coating (anti-ageing) by passivation effect of other mechanism

Now, any normal person can put this report in trash. However, when a group of companies come together for pure commercial interest, and fabricate evidence, the only way to counter this is by bringing out appropriate evidence and research material from established (read un-biased) research institutions.

I request you to add on any information or material in this regard.

PS: I am attaching the report from CMP for your reference. IPK, quite interestingly came out with an independent report with same result (to the decimals) - not attached here.

Attached is a guide from Hempel paint maker that clearly outlines that fume is alkaline and that it can affect the coating performance contrary to the benefit that is outlined in the supposedly independent reports from other paint makers!