Frosty
07-10-2007, 12:52 AM
Having discarded the zink? contaminated wheel wts. per my last post, I discovered my RCBS twenty-pound pot to be coated with a yellow oxide which defied steel brushing and scraping with a steel spoon.
I acquired the pot at a garage sale for a very modest sum and have tolerated a faulty thermostat and a drip for several years. The thermostat is not much of an issue as I control temp. with a thermometer and the on/off switch.
The drip is a nusiance, however, and, as it hasn't responded to antibiotics, I decided to treat it and the attached oxide with boiling water.
Filled the pot with tap water and turned it on. It boiled in five minutes. I refilled as needed and scraped/brushed for about an hour running at least two quarts of boiling water water through the valve/spout.
The drip persisted for thirty minutes at about the rate noted during casting, then slowed and ceased completely. I had disassembled and cleaned the valve parts and interier of the spout with abraisives prior to the water treatment, but suspect that oxide and debris persisted where the valve rod meets the seat. Apparently repeated flushing cured the problem.
The oxide coating also responded to the hot water etc. Some negligible residue remains and I will see if it contaminates my next casting.
Some words of caution. Keep the water level far enough below the top to prclude its running over and into the insulation surrounding the pot. After clearing the spout/pot adequately, pour the remaining water from the pot as draining the dregs through the spout may plug it or coat it with wet oxide. Rinse the pot thereafter. Discard the water safely as it will be contaminated with lead. Blow the valve works dry with compressed air (canned computer air works fine), then heat the pot long enough to thoroughly dry it.
GL
I acquired the pot at a garage sale for a very modest sum and have tolerated a faulty thermostat and a drip for several years. The thermostat is not much of an issue as I control temp. with a thermometer and the on/off switch.
The drip is a nusiance, however, and, as it hasn't responded to antibiotics, I decided to treat it and the attached oxide with boiling water.
Filled the pot with tap water and turned it on. It boiled in five minutes. I refilled as needed and scraped/brushed for about an hour running at least two quarts of boiling water water through the valve/spout.
The drip persisted for thirty minutes at about the rate noted during casting, then slowed and ceased completely. I had disassembled and cleaned the valve parts and interier of the spout with abraisives prior to the water treatment, but suspect that oxide and debris persisted where the valve rod meets the seat. Apparently repeated flushing cured the problem.
The oxide coating also responded to the hot water etc. Some negligible residue remains and I will see if it contaminates my next casting.
Some words of caution. Keep the water level far enough below the top to prclude its running over and into the insulation surrounding the pot. After clearing the spout/pot adequately, pour the remaining water from the pot as draining the dregs through the spout may plug it or coat it with wet oxide. Rinse the pot thereafter. Discard the water safely as it will be contaminated with lead. Blow the valve works dry with compressed air (canned computer air works fine), then heat the pot long enough to thoroughly dry it.
GL