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| The homebrew vacuum chamber lid. | The leaky hose fitting repaired with a puddle of moldmax. |
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| A simple galvanized threaded pipe T is used to provide the relief valve's connection port. | These machined brass garden hose connectors are used to let me swap out the new lid with the old working one.. | |
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| I used a cheep engine vacuum gauge and attached it to the port on the vacuum pump's smaller port. | |
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When I tried out the lid I found I had made the hole for the
brass fitting to large, the assembly wouldn't hold a vacuum and I could hear the
air leaking in around the hole. I filled the gaps by: Using Alumilite's Synthetic Modeling Clay to build a dam around the fitting, Pouring in rubber, and vacuuming the pot and lid down. This let me make sure rubber flowed down between the brass threads and plexiglass. It dripped a little while curing but the dam was high and I had filled it plenty full. There is also a brass fitting inline between the vacuum pump's hard line hose (it's a natural gas line feeder) and the vinyl tube. This is a nice brass male female water hose set. Their openings are large, they are cheep, and secure easily. The hose and fitting's inner diameters really effect the speed at which the vacuum pump can get the pressure down. I added this quick connect so I could more easily switch between this lid and my original lid, just incase it didn't work. As noted it was a long process to get this lid setup and it was nice not to lock out the vacuuming setup while waiting for each stage to get worked out. Also note the T section with cutoff valve. This allows me to release the vacuum quickly. I also use it to make sure degassing RTV doesn't boil up over its container releasing a little vacuum while the pump is running but letting the rubber fall back down. In this manner I might vacuum, to the point of over flow, quickly relieve the pressure, let the mixture settle back a little, close and let the vacuum build/drop, until the moment when the mixture has released all the internal air pockets. One can see this easily , it looks as though the whole bubbling mess has popped some big internal bubble, and it settles back down to it's post mixing level, still 'boiling' but no longer rising. |
| PaintPot to Pressure Pot, Lid conversion | Home | Techamges @ Butch O'hare |
| Replacing the rubber gasket on a lid, & examining the vacuum chamber lid | Up | Homebrew Electric Hollow-Caster |