Shop Coating Inspection
Shop priming failures on new tanks have been a persistent problem for consultants and owners. From our experience, they are not limited to a particular contractor and problems appear widespread. We don’t believe that this is either a material or specification issue. However, quality control in some fabrication facilities appears to be sorely lacking. For this reason, many of the consultants we work for have Dixon inspect all of the surface preparation and priming of new tank steel at the contractors’ facilities.
Historically we haven’t done a lot of this inspection, as it isn’t possible for us to give an accurate budget estimate for shop inspection services before the project is bid. Most consultants need our total cost estimate for inspection prior to bidding and sometimes need to submit our cost at the proposal stage. Unlike field inspection where we know the amount of travel and approximate number of inspections, shop priming requirements aren’t known until after the project is bid. Tank builders have major facilities in Texas, Iowa, Kentucky, Indiana, South Dakota, and Ontario. Some can blast and prime all steel in a few days during one trip. Others may do sections of the tank weeks apart, requiring numerous trips. Since we couldn’t give consultants this cost estimate in advance of bidding, it usually was ignored and everyone just crossed their fingers that the shop priming would be done correctly.
But as problems have worsened, we have developed specification language for consultants. It makes the cost of shop inspection the responsibility of the contractor, but does not allow them to hire their own inspector, thus eliminating a conflict of interest. The contractors know where their facilities are and how many trips and hours our inspector will need, so they can accurately figure this cost into their bids. This has allowed owners to cost effectively inspect the 80% of the tank steel surface area that is primed in the shop. This should eliminate many of the problems that owners and consultants have had to deal with on new tanks. Many of these failures are not evident until after the warranty has expired, and it is often difficult or impossible to get the contractor to agree on their degree of responsibility and/or to perform repairs. Even if they do repairs out of warranty, there is no guarantee that all failures have become visible and new failures can continue to develop.
New tanks have increased substantially in cost and needless to say, owners do not expect to deal with premature painting expenses. The total cost of shop and field coating inspection tends to be a very small part of the project cost and most owners find this to be a worthwhile expenditure.
