Tank preparation

The first rule - do not scrape the surface prior to the GreaseMaster application Case study In 1997 the Sea-Land Discovery had the forepeak tank cleaned from Eureka Gel B soft coating with the GreaseMaster. A 2-man crew operated the 3200-psi pressure washer at a temperature of 145F and cleaned 25000 sq.ft. in 10 hours. Material cost was 75 cents per sq.ft. and the job was completed within the allocated time. In 1998 the Sea-Land Challenger came in to Long Beach Port for cleaning of the forepeak tank. Without telling us, the crew had scraped the tank, thinking that this procedure would reduce the cleaning time and also result in less GreaseMaster use. The same 2-man team did the job on this vessel. The results were surprising, unfortunately in a negative way. The actual cleaning time was 18 hours for the same 25,000 sq.ft. and the product cost increased to 97 cents per sq.ft. The fact is that the scraping of the soft coating pushes the greasy residues even further into the pores of the steel, making it much harder and time consuming to remove all deposits from the substrate. An 80% increase in man hours and a 60% higher product cost are clear evidence to the fact that pre-scraping of soft coatings prior to the GreaseMaster application is a futile effort, in fact it is counterproductive to our technology. Equipment 3200-psi pressure washer, 6.6 gpm water flow; Hot water capability and soap intake, for direct injection of the GreaseMaster; Spin nozzle and angled attachments to clean below stiffeners and other hard to reach areas; Diaphragm pump with 2" hose to pump sludge from the bottom of the tank; Slop or waste disposal tank to collect the sludge and let the oil and grease residues separate from the wastewater; Black light to test for grease deposits. NOTE: The step-by-step cleaning procedure and the suggested equipment to perform it may vary from rig to rig, or tank to tank, depending on what the actual conditions are in each case. Based on past experience in removing grease coatings we have found it may be necessary to adjust the application and/or wash-off procedures reflecting the actual tank conditions, equipment availability and/or tank accessability. We have listed these various methods below:

Standard Cleaning Procedure
Step 1:	Pre-dilute the GreaseMaster at 100:1
Step 2:	Insert soap hose into the GreaseMaster solution
Step 3:	Attach spin nozzle to gun and start the pressure washer
Step 4:	Set temperature at 150F-180F
Step 5:	Hold gun tip about 4-6 inches from surface
Step 6:	Commence cleaning from the top of the tank
Step 7:	Start diaphragm pump to remove sludge
Step 8:	Proceed cleaning form the overheads downwards
Step 9:	If necessary adjust pressure by moving gun away from surface
Step 10:	Clean surface methodically moving gun up and down and sideways
Step 11:	Use angled tips to clean difficult to reach areas
Step 12:	Use short gun attachments in confined areas
Step 13:	Continue operating diaphragm pump
Step 14:	If flash rust is a concern use DH or ventilation to keep at minimum
Step 15:	Remove final standing water/sludge with vaccuum pump
Step 16:	Let the solution separate for 48 hours in the holding tank
Step 17:	Skim grease/oil residues from top and dispose as hazardous material
Step 18:	Test water for oil content and dispose as non-hazardous rinse water
Step 19:	Remove bottom sludge as hazardous material
Step 20:	Test cleaned surface with black light for grease residues
Step 21:	Spot clean any area missed during cleaning
Step 22:	Inspect for steel replacement or proceed with coating preparation
Step 23:	If steel has been replaced, wash tank again with the GreaseMaster
Alternative Cleaning Procedure

a)	If no soap intake is available on the pressure washer then the GreaseMaster is to be applied by an airless sprayer at a pre-dilution of 50:1. Let it cure for 24 hours and then wash off with hot water at a temperature level of 130-180F.
b)	If no airless sprayer is available, then the GreaseMaster can be applied with a 'bug sprayer' or Hudson Sprayer at the same dilution factor of 50:1 (approximately 8oz GreaseMaster to 2.5-gal water).
c)	In some cases the soft coating has become very hard over a long period of time, in fact it is almost like a hard coating. In such a case the GreaseMaster is applied in the same fashion, but the wash-off has to be done with a UHP blaster.
d)	If no hot water washer is available and the wash off is done in cold water, it may be necessary to do an extra GreaseMaster application in order to remove all deposits.
e)	When calculating the product amount needed for an application, it is prudent to add 50% to the surface area to cover all stiffeners, stringers, difficult to reach areas, run-off and overspray.
f)	The GreaseMaster will also remove salt deposits during the removal of soft coatings and meets U.S. Navy specs on allowable salt deposits.
SURFACE STANDARD   The GreaseMaster Technology provides a surface that will be free of oil, grease or fat deposits, which can now be safely inspected for steel replacements or can be hard coated. This treatment is compatible with any one coat or two coat epoxy systems. Salt deposits have been reduced to levels that meet U.S. Navy specs. PRODUCTION RATE   A 2-man crew per each gun will be able to treat about 1500-2000 sq.ft. per hour. © 2005 Michael H. Nahm RUSTECO LLC GREASEMASTER is a federally registered trademark of RUSTECO LLC, California, USA