To find an efficient means of removing the gypsum build- up from inside railroad tank cars.
Gypsum is a by-product of phosphate which is used as fertilizer. This gypsum must be hauled from the phosphate field for further processing into wallboard, etc. The railroad cars used for hauling the gypsum are rubber lined for corrosion resistance. After a short period of time, the gypsum builds up on the inside of the tankers and must be removed because of the increasing weight added to the train. Sandblasting is formerly used to remove the gypsum, but because it leaves a mess and often removes a great deal of the rubber coating on the inside of the tanks, a better method is used. Now high pressure sprayer is used. The spray works its way under the edge of the thick gypsum build-up and blasts it free. The pressure and flow varies depending upon the thickness of the gypsum build-up. The new pressure sprayer is also used to clean the dirty exterior of the tankers, because the identification markings must be visible. With the old sandblasting method, many of the markings were removed along with the dirt and these were time consuming and expensive.
After spraying, the gypsum begins to erode and the spray gets under the edge and blasts large sections free from the rubber wall.