Nice trick for making a whole bigger, I have had to do that a couple times, and did not think of that... (Just tried to hold it very steady, and went slow, It helped that I usually only work with drywall or soft materials..)
Is the sink going to drain into the black tank vent tube? I am Not a plumber, but not sure that's good practice. Would think the air across the vent could suck the water out the sink U trap, and let the gases in to the coach through the now empty sink drain. But again I am not a plumber, so could be wrong. On the other hand, I guess if you get a sink with a closed drain you have to operate to let the water out (i.e. spring loaded to stay closed), you might not need a U trap, so would not be a problem. (I just know enough plumbing to be dangerous, not competent. 🤣)
You are not wrong, ideally you should have a separate drain. When you flush the toilet air is moving out of the tank through the vent line, I suppose it could act like a venturi but I doubt it will. I'll let you know what happens.
![ถามตรงๆ กับ อาจตุพร ทำไม ประเทศไทย ใครเป็นนายก ก็โดนด่า พอออกเเล้วคนคิดถึง!!?? l [Nickynachat]](http://i.ytimg.com/vi/3YFLMXxBGAs/mqdefault.jpg)
Nice trick for making a whole bigger, I have had to do that a couple times, and did not think of that... (Just tried to hold it very steady, and went slow, It helped that I usually only work with drywall or soft materials..)
The trick works well
Is the sink going to drain into the black tank vent tube? I am Not a plumber, but not sure that's good practice. Would think the air across the vent could suck the water out the sink U trap, and let the gases in to the coach through the now empty sink drain. But again I am not a plumber, so could be wrong.
On the other hand, I guess if you get a sink with a closed drain you have to operate to let the water out (i.e. spring loaded to stay closed), you might not need a U trap, so would not be a problem.
(I just know enough plumbing to be dangerous, not competent. 🤣)
You are not wrong, ideally you should have a separate drain. When you flush the toilet air is moving out of the tank through the vent line, I suppose it could act like a venturi but I doubt it will. I'll let you know what happens.